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  • 1.
    Abbas, Malik Waseem
    et al.
    Natl Inst Biotechnol and Genet Engn, Pakistan.
    Soomro, Razium Ali
    Natl Inst Biotechnol and Genet Engn, Pakistan; Univ Sindh, Pakistan; Univ Bristol, England.
    Kalwar, Nazar Hussain
    Shah Abdul Latif Univ, Pakistan.
    Zahoor, Mehvish
    Natl Inst Biotechnol and Genet Engn, Pakistan.
    Avci, Ahmet
    Selcuk Univ, Turkey.
    Pehlivan, Erol
    Selcuk Univ, Turkey.
    Hallam, Keith Richard
    Univ Bristol, England.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Carbon quantum dot coated Fe3O4 hybrid composites for sensitive electrochemical detection of uric acid2019Ingår i: Microchemical journal (Print), ISSN 0026-265X, E-ISSN 1095-9149, Vol. 146, s. 517-524Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study explores carbon quantum dots (C-dots) as potential candidates for enhancing the signal sensitivity of an electrochemical sensor devised for biologically important molecule, such as uric acid (UA). The C-dots were evaluated for their electrochemical characteristics in combination with Fe3O4 nanoparticles (Fe3O4 NPs), which were applied as the primary electro-catalytic promoter. The hybrid nanocomposite (C-dots/Fe3O4 HCs) formation was achieved by facilitating the adsorption of C-dots over Fe3O4 NPs using amine-carbonyl interactions. Unlike, one pot method, the proposed strategy enables aggregation-free coverage of Fe3O4 NPs with highly conductive layer of C-dots that can act as conduction centres to support ultra-fast electron transfer kinetics to satisfy the need of high signal sensitivity. The hybrid composite demonstrated remarkable signal improvement when tested against the electrochemical oxidation of UA. The heighten current response and lower over-potential values enabled development of a DC-amperometric (DC-AMP) sensor for UA with a linear working range of 0.01 to 0.145 mu M and signal sensitivity measurable up to 6.0 x 10(-9) M. The said improvement was manifested as a synergetic outcome of active redox couple (Fe (III/II)), larger surface area of Fe3O4 NPs engulfed with a layer of highly conductive C-dots acting as efficient charge sensitisers.

  • 2.
    Abbas, Zaheer
    et al.
    Beijing Univ Chem Technol, Peoples R China.
    Soomro, Razium Ali
    Beijing Univ Chem Technol, Peoples R China; Beijing Univ Chem Technol, Peoples R China.
    Kalwar, Nazar Hussain
    Shah Abdul Latif Univ Khairpur, Pakistan.
    Tunesi, Mawada
    Beijing Univ Chem Technol, Peoples R China.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Karakus, Selcan
    Istanbul Univ Cerrahpa Avcilar, Turkey.
    Kilislioglu, Ayben
    Istanbul Univ Cerrahpa Avcilar, Turkey.
    In Situ Growth of CuWO4 Nanospheres over Graphene Oxide for Photoelectrochemical (PEC) Immunosensing of Clinical Biomarker2020Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, SENSORS, Vol. 20, nr 1, artikel-id 148Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Procalcitonin (PCT) protein has recently been identified as a clinical marker for bacterial infections based on its better sepsis sensitivity. Thus, an increased level of PCT could be linked with disease diagnosis and therapeutics. In this study, we describe the construction of the photoelectrochemical (PEC) PCT immunosensing platform based on it situ grown photo-active CuWO4 nanospheres over reduced graphene oxide layers (CuWO4@rGO). The in situ growth strategy enabled the formation of small nanospheres (diameter of 200 nm), primarily composed of tiny self-assembled CuWO4 nanoparticles (2-5 nm). The synergic coupling of CuWO4 with rGO layers constructed an excellent photo-active heterojunction for photoelectrochemical (PEC) sensing. The platform was then considered for electrocatalytic (EC) mechanism-based detection of PCT, where inhibition of the photocatalytic oxidation signal of ascorbic acid (AA), subsequent to the antibody-antigen interaction, was recorded as the primary signal response. This inhibition detection approach enabled sensitive detection of PCT in a concentration range of 10 pgmL(-1) to 50 ng.mL(-1) with signal sensitivity achievable up to 0.15 pgmL(-1). The proposed PEC hybrid (CuWO4@rGO) could further be engineered to detect other clinically important species.

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  • 3. Beställ onlineKöp publikationen >>
    Adam, Rania Elhadi
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Synthesis and Characterization of Some Nanostructured Materials for Visible Light-driven Photo Processes2020Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Nanostructured materials for visible light driven photo-processes such as photodegradation of organic pollutants and photoelectrochemical (PEC) water oxidation for hydrogen production are very attractive because of the positive impact on the environment. Metal oxides-based nanostructures are widely used in these photoprocesses due to their unique properties. But single nanostructured metal oxide material might suffer from low efficiency and instability in aqueous solutions under visible light. These facts make it important to have an efficient and reliable nanocomposite for the photo-processes. The combination of different nanomaterials to form a composite configuration can produce a material with new properties. The new properties which are due to the synergetic effect, are a combination of the properties of all the counterparts of the nanocomposite. Zinc oxides (ZnO) have unique optical and electrical properties which grant it to be used in optoelectronics, sensors, solar cells, nanogenerators, and photocatalysis activities. Although ZnO absorbs visible light from the sun due to the deep level band, it mainly absorbs ultraviolet wavelengths which constitute a small portion of the whole solar spectrum range. Also, ZnO has a problem with the high recombination rate of the photogenerated electrons. These problems might reduce its applicability to the photo-process. Therefore, our aim is to develop and investigate different nanocomposites materials based on the ZnO nanostructures for the enhancement of photocatalysis processes using the visible solar light as a green source of energy. Two photo-processes were applied to examine the developed nanocomposites through photocatalysis: (1) the photodegradation of organic dyes, (2) PEC water splitting. In the first photo-process, we used the ZnO nanoparticles (NPs), Magnesium (Mg)-doped ZnO NPs, and plasmonic ZnO/graphene-based nanocomposite for the decomposition of some organic dyes that have been used in industries. For the second photo-process, ZnO photoelectrode composite with different silver-based semiconductors to enhance the performance of the ZnO photoelectrode was used for PEC reaction analysis to perform water splitting. The characterization and photocatalysis experiment results showed remarkable enhancement in the photocatalysis efficiency of the synthesized nanocomposites. The observed improved properties of the ZnO are due to the synergetic effects are caused by the addition of the other nanomaterials. Hence, the present thesis attends to the synthesis and characterization of some nanostructured materials composite with ZnO that are promising candidates for visible light-driven photo-processes.  

    Delarbeten
    1. Synthesis of ZnO nanoparticles by co-precipitation method for solar driven photodegradation of Congo red dye at different pH
    Öppna denna publikation i ny flik eller fönster >>Synthesis of ZnO nanoparticles by co-precipitation method for solar driven photodegradation of Congo red dye at different pH
    2018 (Engelska)Ingår i: PHOTONICS AND NANOSTRUCTURES-FUNDAMENTALS AND APPLICATIONS, ISSN 1569-4410, Vol. 32, s. 11-18Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Solar driven photocatalytic processes to remove organic pollutants from wastewater and other aqueous solutions is very important and useful due to its environmental benefits regarding sustainability aspect. In this article, we report a study on the use of bare zinc oxide (ZnO) nanoparticles (NPs) prepared by the chemical low temperature co-precipitation method and used as a catalyst to degrade the Congo red dye from aqueous solution using solar radiation. We performed the photocatalytic experiments for degradation of Congo red dye under solar radiation at different pH values. The results showed that the ZnO NPs are effective under solar radiation for degradation of Congo red dye. Even when the pH was varied down to 4 or raised to 10, the degradation was observed to be slightly improved. This result is due to the excess of radicals species, which enhance the photocatalytic process. In general, the observed degradation efficiency of the ZnO NPs is due to the deep level defects within the band gap that were introduced during the growth process of the ZnO NPs, which enhance the absorption wavelength band towards the visible light region. Recycling of the ZnO NPs for 3 successive runs have indicated the feasibility of reusing the NPs for several times. This implies that by using bare ZnO NPs an efficient approach for degradation of toxic waste can be achieved. Radical scavengers were used to evaluate the role of the radicals in the reaction mechanism.

    Ort, förlag, år, upplaga, sidor
    ELSEVIER SCIENCE BV, 2018
    Nyckelord
    ZnO nanoparticles; Point defects; Photocatalytic
    Nationell ämneskategori
    Atom- och molekylfysik och optik
    Identifikatorer
    urn:nbn:se:liu:diva-153525 (URN)10.1016/j.photonics.2018.08.005 (DOI)000451653700003 ()
    Anmärkning

    Funding Agencies|department of Science and Technology, Linkoping University, Sweden

    Tillgänglig från: 2018-12-20 Skapad: 2018-12-20 Senast uppdaterad: 2020-03-18
    2. Synthesis of Mg-doped ZnO NPs via a chemical low-temperature method and investigation of the efficient photocatalytic activity for the degradation of dyes under solar light
    Öppna denna publikation i ny flik eller fönster >>Synthesis of Mg-doped ZnO NPs via a chemical low-temperature method and investigation of the efficient photocatalytic activity for the degradation of dyes under solar light
    Visa övriga...
    2020 (Engelska)Ingår i: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 99, artikel-id 106053Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Doped semiconductors nanostructures (NSs) have shown great interest as a potential for green and efficient photocatalysis activities. Magnesium (Mg)-doped zinc oxide (ZnO) nanoparticles (NPs) has been synthesized by a one-step chemical low temperature (60 °C) co-precipitation method without further calcination and their photocatalytic performance for photodegradation of Methylene blue (MB) dye under the illumination of solar light is investigated. The crystal structure of the synthesized NPs is examined by X-ray diffraction (XRD). XRD data indicates a slight shift towards higher 2θ angle in Mg-doped samples as compared to the pure ZnO NPs which suggest the incorporation of Mg2+ into ZnO crystal lattice. X-ray photoelectron spectroscopy (XPS), UV–Vis spectrophotometer and cathodoluminescence (CL) spectroscopy, were used to study electronics, and optical properties, respectively. The XPS analysis confirms the substitution of the Zn2+ by the Mg2+ into the ZnO crystal lattice in agreement with the XRD data. The photocatalytic activities showed a significant enhancement of the Mg-doped ZnO NPs in comparison with pure ZnO NPs. Hole/radical scavengers were used to reveal the mechanism of the photodegradation. It was found that the addition of the Mg to the ZnO lattices increases the absorption of the hydroxyl ions at the surface of the NPs and hence acts as a trap site leading to decrease the electron-hole pair and consequently enhancing the photodegradation.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2020
    Nyckelord
    ZnO nanoparticles, Mg-doped ZnO NPs, Photocatalytic, Photodegradation, Methylene blue, Congo red
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:liu:diva-164333 (URN)10.1016/j.solidstatesciences.2019.106053 (DOI)000516720100024 ()2-s2.0-85074706430 (Scopus ID)
    Tillgänglig från: 2020-03-18 Skapad: 2020-03-18 Senast uppdaterad: 2020-03-24Bibliografiskt granskad
    3. Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities
    Öppna denna publikation i ny flik eller fönster >>Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities
    Visa övriga...
    2019 (Engelska)Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 52, s. 30585-30598Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    High-efficiency photocatalysts are crucial for the removal of organic pollutants and environmental sustainability. In the present work, we report on a new low-temperature hydrothermal chemical method, assisted by ultrasonication, to synthesize disruptive plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis. The plasmonic nanocomposites were investigated by a wide range of characterization techniques, confirming successful formation of photocatalysts with excellent degradation efficiency. Using Congo red as a model dye molecule, our experimental results demonstrated a photocatalytic reactivity exceeding 90% efficiency after one hour simulated solar irradiation. The significantly enhanced degradation efficiency is attributed to improved electronic properties of the nanocomposites by hybridization of the graphene and to the addition of Ag/AgI which generates a strong surface plasmon resonance effect in the metallic silver further improving the photocatalytic activity and stability under solar irradiation. Scavenger experiments suggest that superoxide and hydroxyl radicals are responsible for the photodegradation of Congo red. Our findings are important for the fundamental understanding of the photocatalytic mechanism of ZnO/graphene/Ag/AgI nanocomposites and can lead to further development of novel efficient photocatalyst materials.

    Ort, förlag, år, upplaga, sidor
    Royal Meteorological Society, 2019
    Nationell ämneskategori
    Den kondenserade materiens fysik
    Identifikatorer
    urn:nbn:se:liu:diva-160568 (URN)10.1039/C9RA06273D (DOI)000487989300064 ()
    Anmärkning

    Funding agencies: Department of Science and Technology (ITN) at Campus Norrkoping, Linkoping University, Sweden; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation

    Tillgänglig från: 2019-09-30 Skapad: 2019-09-30 Senast uppdaterad: 2020-03-18Bibliografiskt granskad
    4. n–n ZnO–Ag2CrO4 heterojunction photoelectrodes with enhanced visible-light photoelectrochemical properties
    Öppna denna publikation i ny flik eller fönster >>n–n ZnO–Ag2CrO4 heterojunction photoelectrodes with enhanced visible-light photoelectrochemical properties
    Visa övriga...
    2019 (Engelska)Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 14, s. 7992-8001Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In this study, ZnO nanorods (NRs) were hydrothermally grown on an Au-coated glass substrate at a relatively low temperature (90 °C), followed by the deposition of Ag2CrO4 particles via a successive ionic layer adsorption and reaction (SILAR) route. The content of the Ag2CrO4 particles on ZnO NRs was controlled by changing the number of SILAR cycles. The fabricated ZnO–Ag2CrO4 heterojunction photoelectrodes were subjected to morphological, structural, compositional, and optical property analyses; their photoelectrochemical (PEC) properties were investigated under simulated solar light illumination. The photocurrent responses confirmed that the ability of the ZnO–Ag2CrO4 heterojunction photoelectrodes to separate the photo-generated electron–hole pairs is stronger than that of bare ZnO NRs. Impressively, the maximum photocurrent density of about 2.51 mA cm−2 at 1.23 V (vs. Ag/AgCl) was measured for the prepared ZnO–Ag2CrO4 photoelectrode with 8 SILAR cycles (denoted as ZnO–Ag2CrO4-8), which exhibited about 3-fold photo-enhancement in the current density as compared to bare ZnO NRs (0.87 mA cm−2) under similar conditions. The improvement in photoactivity was attributed to the ideal band gap and high absorption coefficient of the Ag2CrO4 particles, which resulted in improved solar light absorption properties. Furthermore, an appropriate annealing treatment was proven to be an efficient process to increase the crystallinity of Ag2CrO4 particles deposited on ZnO NRs, which improved the charge transport characteristics of the ZnO–Ag2CrO4-8 photoelectrode annealed at 200 °C and increased the performance of the photoelectrode. The results achieved in the present work present new insights for designing n–n heterojunction photoelectrodes for efficient and cost-effective PEC applications and solar-to-fuel energ

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2019
    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:liu:diva-155657 (URN)10.1039/C9RA00639G (DOI)000462646000051 ()2-s2.0-85062919263 (Scopus ID)
    Anmärkning

    Funding agencies: University of Mohaghegh Ardabili-Iran and Linkoping University-Sweden; AForsk [17-457

    Tillgänglig från: 2019-03-22 Skapad: 2019-03-22 Senast uppdaterad: 2020-03-18Bibliografiskt granskad
    5. ZnO/Ag/Ag2WO4 photo-electrodes with plasmonic behavior for enhanced photoelectrochemical water oxidation
    Öppna denna publikation i ny flik eller fönster >>ZnO/Ag/Ag2WO4 photo-electrodes with plasmonic behavior for enhanced photoelectrochemical water oxidation
    Visa övriga...
    2019 (Engelska)Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 15, s. 8271-8279Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Ag-based compounds are excellent co-catalyst that can enhance harvesting visible light and increase photo-generated charge carrier separation owing to its surface plasmon resonance (SPR) effect in photoelectrochemical (PEC) applications. However, the PEC performance of a ZnO/Ag/Ag2WO4 heterostructure with SPR behavior has not been fully studied so far. Here we report the preparation of a ZnO/Ag/Ag2WO4 photo-electrode with SPR behavior by a low temperature hydrothermal chemical growth method followed by a successive ionic layer adsorption and reaction (SILAR) method. The properties of the prepared samples were investigated by different characterization techniques, which confirm that Ag/Ag2WO4 was deposited on the ZnO NRs. The Ag2WO4/Ag/ZnO photo-electrode showed an enhancement in PEC performance compared to bare ZnO NRs. The observed enhancement is attributed to the red shift of the optical absorption spectrum of the Ag2WO4/Ag/ZnO to the visible region (>400 nm) and to the SPR effect of surface metallic silver (Ag0) particles from the Ag/Ag2WO4 that could generate electron–hole pairs under illumination of low energy visible sun light. Finally, we proposed the PEC mechanism of the Ag2WO4/Ag/ZnO photo-electrode with an energy band structure and possible electron–hole separation and transportation in the ZnO/Ag/Ag2WO4 heterostructure with SPR effect for water oxidation. ER

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2019
    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:liu:diva-155655 (URN)10.1039/C8RA10141H (DOI)000461445300016 ()
    Tillgänglig från: 2019-03-22 Skapad: 2019-03-22 Senast uppdaterad: 2020-03-18Bibliografiskt granskad
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  • 4.
    Adam, Rania Elhadi
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Alnoor, Hatim
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten.
    Pozina, Galia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Liu, Xianjie
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Nur, Omer
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Synthesis of Mg-doped ZnO NPs via a chemical low-temperature method and investigation of the efficient photocatalytic activity for the degradation of dyes under solar light2020Ingår i: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 99, artikel-id 106053Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Doped semiconductors nanostructures (NSs) have shown great interest as a potential for green and efficient photocatalysis activities. Magnesium (Mg)-doped zinc oxide (ZnO) nanoparticles (NPs) has been synthesized by a one-step chemical low temperature (60 °C) co-precipitation method without further calcination and their photocatalytic performance for photodegradation of Methylene blue (MB) dye under the illumination of solar light is investigated. The crystal structure of the synthesized NPs is examined by X-ray diffraction (XRD). XRD data indicates a slight shift towards higher 2θ angle in Mg-doped samples as compared to the pure ZnO NPs which suggest the incorporation of Mg2+ into ZnO crystal lattice. X-ray photoelectron spectroscopy (XPS), UV–Vis spectrophotometer and cathodoluminescence (CL) spectroscopy, were used to study electronics, and optical properties, respectively. The XPS analysis confirms the substitution of the Zn2+ by the Mg2+ into the ZnO crystal lattice in agreement with the XRD data. The photocatalytic activities showed a significant enhancement of the Mg-doped ZnO NPs in comparison with pure ZnO NPs. Hole/radical scavengers were used to reveal the mechanism of the photodegradation. It was found that the addition of the Mg to the ZnO lattices increases the absorption of the hydroxyl ions at the surface of the NPs and hence acts as a trap site leading to decrease the electron-hole pair and consequently enhancing the photodegradation.

  • 5.
    Adam, Rania Elhadi
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Chalangar, Ebrahim
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten. School of Information Technology, Halmstad University, Halmstad, Sweden.
    Pirhashemi, Mahsa
    Department of Chemistry, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran.
    Pozina, Galia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Palisaitis, Justinas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Pettersson, Håkan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten. School of Information Technology, Halmstad University, Halmstad, Sweden; Solid State Physics and NanoLund, Lund University, Lund, Sweden.
    Willander, Magnus
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities2019Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 52, s. 30585-30598Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-efficiency photocatalysts are crucial for the removal of organic pollutants and environmental sustainability. In the present work, we report on a new low-temperature hydrothermal chemical method, assisted by ultrasonication, to synthesize disruptive plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis. The plasmonic nanocomposites were investigated by a wide range of characterization techniques, confirming successful formation of photocatalysts with excellent degradation efficiency. Using Congo red as a model dye molecule, our experimental results demonstrated a photocatalytic reactivity exceeding 90% efficiency after one hour simulated solar irradiation. The significantly enhanced degradation efficiency is attributed to improved electronic properties of the nanocomposites by hybridization of the graphene and to the addition of Ag/AgI which generates a strong surface plasmon resonance effect in the metallic silver further improving the photocatalytic activity and stability under solar irradiation. Scavenger experiments suggest that superoxide and hydroxyl radicals are responsible for the photodegradation of Congo red. Our findings are important for the fundamental understanding of the photocatalytic mechanism of ZnO/graphene/Ag/AgI nanocomposites and can lead to further development of novel efficient photocatalyst materials.

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  • 6.
    Aftab, Umair
    et al.
    Mehran Univ Engn and Technol, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Mazzaro, Raffaello
    Italian Natl Res Council, Italy.
    Abro, Muhammad Ishaq
    Mehran Univ Engn and Technol, Pakistan.
    Baloch, Muhammad Moazam
    Mehran Univ Engn and Technol, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Yu, Cong
    Chinese Acad Sci, Peoples R China.
    Ibupoto, Zafar Hussain
    Univ Sindh, Pakistan.
    The chemically reduced CuO-Co3O4 composite as a highly efficient electrocatalyst for oxygen evolution reaction in alkaline media2019Ingår i: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 9, nr 22, s. 6274-6284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The fabrication of efficient, alkaline-stable and nonprecious electrocatalysts for the oxygen evolution reaction is highly needed; however, it is a challenging task. Herein, we report a noble metal-free advanced catalyst, i.e. the chemically reduced mixed transition metal oxide CuO-Co3O4 composite, with outstanding oxygen evolution reaction activity in alkaline media. Sodium borohydride (NaBH4) was used as a reducing agent for the mixed transition metal oxide CuO-Co3O4. The chemically reduced composite carried mixed valence states of Cu and Co, which played a dynamic role in driving an excellent oxygen evolution reaction process. The X-ray photo-electron spectroscopy (XPS) study confirmed high density of active sites in the treated sample with a large number of oxygen vacancies. The developed electrocatalyst showed the lowest overpotential of 144.5 mV vs. the reversible hydrogen electrode (RHE) to achieve the current density of 40 mA cm(-2) and remained stable for 40 hours throughout the chronoamperometry test at the constant potential of 1.39 V vs. RHE. Moreover, the chemically reduced composite was highly durable. Electrochemical impedance spectroscopy (EIS) confirmed the low charge transfer resistance of 13.53 ohms for the chemically reduced composite, which was 50 and 26 times smaller than that of Co3O4 and untreated CuO-Co3O4, respectively. The electrochemically active surface area for the chemically reduced composite was found to be greater than that for pristine CuO, Co3O4 and untreated pristine CuO-Co3O4. These findings reveal the possibility of a new gateway for the capitalization of a chemically reduced sample into diverse energy storage and conversion systems such as lithium-ion batteries and supercapacitors.

  • 7.
    Alvi, Naveed
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Soto Rodriguez, Paul E. D.
    Univ Complutense Madrid, Spain.
    ul Hassan, Waheed
    Bahauddin Zakariya Univ, Pakistan.
    Zhou, Guofu
    South China Normal Univ, Peoples R China.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Notzel, Richard
    South China Normal Univ, Peoples R China.
    Unassisted water splitting with 9.3% efficiency by a single quantum nanostructure photoelectrode2019Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 44, nr 36, s. 19650-19657Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To split water and produce hydrogen by white light is an excellent solution for the storage and supply of clean and sustainable energy. Efficiency and stability are the key challenges for a successful exploitation. InGaN, evaluated against other semiconductors, metal oxides, carbon based - and organic materials has most suited intrinsic materials properties. Based on this optimum materials choice we report photoelectrochemical (PEC) hydrogen generation under white light illumination by an InGaN-based quantum nanostructure photoelectrode. No degradation occurs for operation over 10 h. Our novel concept, combining quantum nanostructure physics with electrochemistry and catalysis leads to almost 10% efficiency at zero external voltage. The efficiency rises above 25% at 0.2 V. This is unmatched for a single photoelectrode, representing the most advanced technology of low complexity. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

  • 8.
    Asghar, A. M.
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för teknik och naturvetenskap.
    Malick, M.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Karlsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska högskolan.
    Hussain, A.
    Chalmers University of Thechnology, Gothenburg, Sweden .
    A multiwideband planar monopole antenna for 4G devices2013Ingår i: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 55, nr 3, s. 589-593Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents a compact multiband planar antenna designed for mobile phone applications.The antenna performance is achieved by designing a planar monopole antenna into distributed radiating elements. The proposed antenna is comprised of a chopped circular radiator appended with a meander line and an L-strip coupled element, which is an extension of the ground plane. The combination of a chopped circular patch and L-shaped coupling strip residing on the top side generates lower band while upper band resonances are attained separately by chopped circular resonator and meander line elements. The antenna shows a planar structure which occupies an area of 56 x 17.6 mm and can be directly printed onto a circuit board at low cost making it especially suitable for mobile phone applications. The manufactured antenna is experimentally verified and covers several wireless communication bands, such as LTE 750, GSM 850, GSM 900, DCS, UMTS-2110, Bluetooth, WLAN, WiMAX, and UWB. The high frequency structure simulation is used to design and analyze the antenna performance, and a practical structure was fabricated and tested. The measured and simulated return loss show good agreement.

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  • 9.
    Atif, M.
    et al.
    King Saud Univ, Saudi Arabia.
    Ait Ali, Abderrahman
    COMSATS Inst Informat Technol, Pakistan.
    AlSalhi, M. S.
    King Saud Univ, Saudi Arabia.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Effect of Urea on the Morphology of Fe3O4 Magnetic Nanoparticles and Their Application in Potentiometric Urea Biosensors2019Ingår i: Silicon, ISSN 1876-990X, E-ISSN 1876-9918, Vol. 11, nr 3, s. 1371-1376Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of different concentrations of urea on the morphology of iron oxide (Fe3O4) magnetic nanoparticles was studied. Fe3O4 magnetic nanoparticles were fabricated by the coprecipitation method. The morphology, crystallinity, compositional purity, and emission characteristics were tested by the techniques of scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Raman characterization. The drop-casting technique was successfully used to fabricate a potentiometric urea biosensor producing initially isopropanol and chitosan solution, consisting of Fe3O4 nanoparticles, on a glass fiber filter. To measure the developed biosensors voltage signal from the functionalized nanoparticles, a copper wire was utilized. The Fe3O4 nanoparticle surface functionalization was performed through the electrostatic immobilization of urease with the Fe3O4-chitosan (CH) nanobiocomposite. The presented urea biosensor measured a wide logarithmic range of urea concentration of 0.1-80 mM with a sensitivity of 42 mV/decade, and indicated a fast response time of approximately 12 s. The developed urea biosensor showed enhanced sensitivity, stability, reusability, and specificity. All experimental results demonstrate the application potential of the developed urea sensor for the monitoring of urea concentrations in human serum, drugs, and food industry-related samples.

  • 10.
    Baravdish, George
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Svensson, Olof
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Gulliksson, M.
    Orebro Univ, Sweden.
    Zhang, Y.
    Shenzhen MSU BIT Univ, Peoples R China; Beijing Inst Technol, Peoples R China.
    Damped second order flow applied to image denoising2019Ingår i: IMA Journal of Applied Mathematics, ISSN 0272-4960, E-ISSN 1464-3634, Vol. 84, nr 6, s. 1082-1111Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we introduce a new image denoising model: the damped flow (DF), which is a second order nonlinear evolution equation associated with a class of energy functionals of an image. The existence, uniqueness and regularization property of DF are proven. For the numerical implementation, based on the Stormer-Verlet method, a discrete DF, SV-DDF, is developed. The convergence of SV-DDF is studied as well. Several numerical experiments, as well as a comparison with other methods, are provided to demonstrate the efficiency of SV-DDF.

  • 11.
    Bernhard, Jonte
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Carstensen, Anna-Karin
    Högskolan i Jönköping.
    Learning of complex concepts: Engineering students’ developing epistemic fluency in an electric circuit theory course2019Ingår i: SEFI annual conference, 2019, Budapest, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    An important aim in engineering education is that students should not only acquire knowledge, but they should be able to use this knowledge in action. I.e. they should develop professional capabilities for knowledgeable action and actionable knowledge. 

    According to Markauskaite and Goodyear professional knowledgeable action requires a holistic, fluent and co-ordinated use of semiotic and material tools, body and environment. Knowledgeable action requires the development of epistemic fluency that involves the ability to smoothly move between abstract, contextual and situated ways of knowing and the capacity to employ multiple epistemic tools. However, the epistemic complexity of knowledgeable action is often underestimated in engineering education. This epistemic complexity has been addressed by Carstensen and Bernhard who have developed the notion of “learning of complex concepts” (LCC-model) that models how students learn to master epistemic tools by “making links”. 

    In this study we have used the LCC-model as an investigatory tool to analyse video-recordings from electric circuit theory courses. The aim was to gain an increased understanding in how students develop epistemic fluency. We will discuss critical features in the design of labs and in the use of real experiments, computer simulations, modelling and other semiotic and material tools in labs for students’ development of epistemic fluency. The results of this study show that labs can be designed to facilitate students’ development of epistemic fluency by making links.

  • 12.
    Bernhard, Jonte
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Carstensen, Anna-Karin
    Jonkoping Univ, Sweden.
    Davidsen, Jacob
    Aalborg Univ, Denmark.
    Ryberg, Thomas
    Aalborg Univ, Denmark.
    Practical Epistemic Cognition in a Design Project-Engineering Students Developing Epistemic Fluency2019Ingår i: IEEE Transactions on Education, ISSN 0018-9359, E-ISSN 1557-9638, Vol. 62, nr 3, s. 216-225Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Contribution: This paper reports engineering students practical epistemic cognition by studying their interactional work in situ. Studying "epistemologies in action" the study breaks away from mainstream approaches that describe this in terms of beliefs or of stage theories. Background: In epistemology, knowledge is traditionally seen as "justified true belief," neglecting knowledge related to action. Interest has increased in studying the epistemologies people use in situated action, and their development of epistemic fluency. How appropriate such approaches are in engineering and design education need further investigation. Research Questions: 1) How do students in the context of a design project use epistemic tools in their interactional work? and 2) What are the implications of the findings in terms of how students cognitive and epistemological development could be conceptualized? Methodology: A collaborative group of six students were video recorded on the 14th day of a fifth-semester design project, as they were preparing for a formal critique session. The entire, almost 6 h, session was recorded by four video cameras mounted in the design studio, with an additional fifth body-mounted camera. The video data collected was analyzed using video ethnographic, conversation analysis, and embodied interaction analysis methods. Findings: The results show that the students use a wealth of bodily material resources as an integral and seamless part of their interactions as epistemic tools, in their joint production of understanding and imagining. The analysis also suggests that students epistemological and cognitive development, individually and as a group, should be understood in terms of developing "epistemic fluency."

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  • 13.
    Bhatti, Adeel Liaquat
    et al.
    Univ Sindh, Pakistan.
    Aftab, Umair
    Mehran Univ Engn and Technol, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Abro, Muhammad Ishaq
    Mehran Univ Engn and Technol, Pakistan.
    Samoon, Muhammad Kashif
    Ctr Pure and Appl Geol Univ Sindh, Pakistan.
    Aghem, Muhammad Hassan
    Ctr Pure and Appl Geol Univ Sindh, Pakistan.
    Bhatti, Muhamad Ali
    Ctr Environm Sci, Pakistan.
    HussainIbupoto, Zafar
    Univ Sindh, Pakistan.
    Facile doping of nickel into Co3O4 nanostructures to make them efficient for catalyzing the oxygen evolution reaction2020Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, RSC ADVANCES, Vol. 10, nr 22, s. 12962-12969Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Designing a facile and low-cost methodology to fabricate earth-abundant catalysts is very much needed for a wide range of applications. Herein, a simple and straightforward approach was developed to tune the electronic properties of cobalt oxide nanostructures by doping them with nickel and then using them to catalyze the oxygen evolution reaction (OER) in an aqueous solution of 1.0 M KOH. The addition of a nickel impurity improved the conductivity of the cobalt oxide, and further increased its activity towards the OER. Analytical techniques such as scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and powder X-ray diffraction (XRD) were used to investigate, respectively, the morphology, composition and crystalline structure of the materials used. The nickel-doped cobalt oxide material showed randomly oriented nanowires and a high density of nanoparticles, exhibited the cubic phase, and contained cobalt, nickel and oxygen as its main elements. The nickel-doped cobalt oxide also yielded a Tafel slope of 82 mV dec(-1) and required an overpotential of 300 mV to reach a current density of 10 mA cm(-2). As an OER catalyst, it was shown to be durable for 40 h. Electrochemical impedance spectroscopy (EIS) analysis showed a low charge-transfer resistance of 177.5 ohms for the nickel-doped cobalt oxide, which provided a further example of its excellent OER performance. These results taken together indicated that nickel doping of cobalt oxide can be accomplished via a facile approach and that the product of this doping can be used for energy and environmental applications.

  • 14.
    Bhatti, Muhammad Ali
    et al.
    Univ Sindh Jamshoro, Pakistan.
    Shah, Aqeel Ahmed
    NED Univ Engn and Technol Karachi, Pakistan.
    Almani, Khalida Faryal
    Univ Sindh Jamshoro, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Chalangar, Seyed Ebrahim
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Chandio, Ali Dad
    NED Univ Engn and Technol Karachi, Pakistan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    Efficient photo catalysts based on silver doped ZnO nanorods for the photo degradation of methyl orange2019Ingår i: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 45, nr 17, s. 23289-23297Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the doped ZnO nanorods with silver (Ag) as photosensitive material are prepared by the solvothermal method. The structural and optical characterization is carried out by the scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy and UV-visible spectroscopy. The use of Ag as dopant did not alter the morphology of ZnO except sample 4 which has flower like morphology. The Ag, Zn and O are the main constituent of doped materials. The XRD revealed a hexagonal phase for ZnO and cubic phase for silver and confirmed the successful doping of Ag. The photocatalytic activity of Ag doped ZnO nanorods was investigated for the photo degradation of methyl orange. The photocatalytic measurements show that 88% degradation of methyl orange by the sample 4 within the 2 h of UV light treatment (365 nm) is significant advancement in the photocatalyst and provide the inexpensive and promising materials for the photochemical applications.

    Publikationen är tillgänglig i fulltext från 2021-08-03 12:55
  • 15.
    Börjesson, Mandus
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Gerner, Håkan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Design and implementation of a high-speed PCI-Express bridge2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This master thesis will cover the prestudy, hardware selection, design and implementation of a PCI Express bridge in the M.2 form factor. The thesis subject was proposed by WISI Norden who wished to extend the functionality of their hardware using an M.2 module. The bridge fits an M-Key M.2 slot and has the dimensions 80x22 mm. It is able to communicate at speeds up to 8 Gb/s over PCI Express and 200 Mbit/s on any of the 20 LVDS/CMOS pins. The prestudy determined that an FPGA should be used and a Xilinx Artix-7 device was chosen. A PCB was designed that hosts the FPGA as well as any power, debugging and other required systems. Associated proof-of-concept software was designed to verify that the bridge operated as expected. The software proves that the bridge works but requires improvement before the bridge can be used to translate sophisticated protocols. The bridge works, with minor hardware modifications, as expected. It fulfills all design requirements set in the master thesis and the FPGA firmware uses a well-established protocol, making further development easier.

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    Design and implementation of a high-speed PCI-Express bridge
  • 16. Beställ onlineKöp publikationen >>
    Chalangar, Ebrahim
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Graphene-based nanocomposites for electronics and photocatalysis2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The development of future electronics depends on the availability of suitable functional materials. Printed electronics, for example, relies on access to highly conductive, inexpensive and printable materials, while strong light absorption and low carrier recombination rates are demanded in photocatalysis industry. Despite all efforts to develop new materials, it still remains a challenge to have all the desirable aspects in a single material. One possible route towards novel functional materials, with improved and unprecedented physical properties, is to form composites of different selected materials.

    In this work, we report on hydrothermal growth and characterization of graphene/zinc oxide (GR/ZnO) nanocomposites, suited for electronics and photocatalysis application. For conductive purposes, highly Al-doped ZnO nanorods grown on graphene nanoplates (GNPs) prevent the GNPs from agglomerating and promote conductive paths between the GNPs. The effect of the ZnO nanorod morphology and GR dispersity on the nanocomposite conductivity and GR/ZnO nanorod bonding strength were investigated by conductivity measurements and optical spectroscopy. The inspected samples show that growth in high pH solutions promotes a better graphene dispersity, higher doping and enhanced bonding between the GNPs and the ZnO nanorods. Growth in low pH solutions yield samples characterized by a higher conductivity and a reduced number of surface defects.

    In addition, different GR/ZnO nanocomposites, decorated with plasmonic silver iodide (AgI) nanoparticles, were synthesized and analyzed for solar-driven photocatalysis. The addition of Ag/AgI generates a strong surface plasmon resonance effect involving metallic Ag0, which redshifts the optical absorption maximum into the visible light region enhancing the photocatalytic performance under solar irradiation. A wide range of characterization techniques including, electron microscopy, photoelectron spectroscopy and x-ray diffraction confirm a successful formation of photocatalysts.

    Our findings show that the novel proposed GR-based nanocomposites can lead to further development of efficient photocatalyst materials with applications in removal of organic pollutants, or for fabrication of large volumes of inexpensive porous conjugated GR-semiconductor composites.

    Delarbeten
    1. Influence of morphology on electrical and optical properties of graphene/Al-doped ZnO-nanorod composites
    Öppna denna publikation i ny flik eller fönster >>Influence of morphology on electrical and optical properties of graphene/Al-doped ZnO-nanorod composites
    Visa övriga...
    2018 (Engelska)Ingår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 29, nr 41, artikel-id 415201Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The development of future 3D-printed electronics relies on the access to highly conductive inexpensive materials that are printable at low temperatures (amp;lt;100 degrees C). The implementation of available materials for these applications are, however, still limited by issues related to cost and printing quality. Here, we report on the simple hydrothermal growth of novel nanocomposites that are well suited for conductive printing applications. The nanocomposites comprise highly Al-doped ZnO nanorods grown on graphene nanoplatelets (GNPs). The ZnO nanorods play the two major roles of (i) preventing GNPs from agglomerating and (ii) promoting electrical conduction paths between the graphene platelets. The effect of two different ZnO-nanorod morphologies with varying Al-doping concentration on the nanocomposite conductivity and the graphene dispersity are investigated. Time-dependent absorption, photoluminescence and photoconductivity measurements show that growth in high pH solutions promotes a better graphene dispersity, higher doping levels and enhanced bonding between the graphene and the ZnO nanorods. Growth in low pH solutions yields samples characterized by a higher conductivity and a reduced number of surface defects. These samples also exhibit a large persistent photoconductivity attributed to an effective charge separation and transfer from the nanorods to the graphene platelets. Our findings can be used to tailor the conductivity of novel printable composites, or for fabrication of large volumes of inexpensive porous conjugated graphene-semiconductor composites.

    Ort, förlag, år, upplaga, sidor
    Institute of Physics Publishing (IOPP), 2018
    Nyckelord
    graphene; zinc oxide; nanorods; nanocomposites; persistent photoconductivity; printing
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:liu:diva-150196 (URN)10.1088/1361-6528/aad3ec (DOI)000440632800001 ()30015332 (PubMedID)2-s2.0-85051665865 (Scopus ID)
    Anmärkning

    Funding Agencies|Knowledge Foundation; Linkoping University; Halmstad University

    Tillgänglig från: 2018-08-22 Skapad: 2018-08-22 Senast uppdaterad: 2019-05-28Bibliografiskt granskad
    2. Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities
    Öppna denna publikation i ny flik eller fönster >>Graphene-based plasmonic nanocomposites for highly enhanced solar-driven photocatalytic activities
    Visa övriga...
    2019 (Engelska)Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 52, s. 30585-30598Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    High-efficiency photocatalysts are crucial for the removal of organic pollutants and environmental sustainability. In the present work, we report on a new low-temperature hydrothermal chemical method, assisted by ultrasonication, to synthesize disruptive plasmonic ZnO/graphene/Ag/AgI nanocomposites for solar-driven photocatalysis. The plasmonic nanocomposites were investigated by a wide range of characterization techniques, confirming successful formation of photocatalysts with excellent degradation efficiency. Using Congo red as a model dye molecule, our experimental results demonstrated a photocatalytic reactivity exceeding 90% efficiency after one hour simulated solar irradiation. The significantly enhanced degradation efficiency is attributed to improved electronic properties of the nanocomposites by hybridization of the graphene and to the addition of Ag/AgI which generates a strong surface plasmon resonance effect in the metallic silver further improving the photocatalytic activity and stability under solar irradiation. Scavenger experiments suggest that superoxide and hydroxyl radicals are responsible for the photodegradation of Congo red. Our findings are important for the fundamental understanding of the photocatalytic mechanism of ZnO/graphene/Ag/AgI nanocomposites and can lead to further development of novel efficient photocatalyst materials.

    Ort, förlag, år, upplaga, sidor
    Royal Meteorological Society, 2019
    Nationell ämneskategori
    Den kondenserade materiens fysik
    Identifikatorer
    urn:nbn:se:liu:diva-160568 (URN)10.1039/C9RA06273D (DOI)000487989300064 ()
    Anmärkning

    Funding agencies: Department of Science and Technology (ITN) at Campus Norrkoping, Linkoping University, Sweden; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation

    Tillgänglig från: 2019-09-30 Skapad: 2019-09-30 Senast uppdaterad: 2020-03-18Bibliografiskt granskad
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  • 17.
    Elhadi Adam, Rania Elhadi
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Alnoor, Hatim
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Pozina, Galia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Synthesis of Mg-doped ZnO NPs via a chemical low-temperature method and investigation of the efficient photocatalytic activity for the degradation of dyes under solar light2020Ingår i: Solid State Sciences, ISSN 1293-2558, E-ISSN 1873-3085, Vol. 99, artikel-id 106053Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Doped semiconductors nanostructures (NSs) have shown great interest as a potential for green and efficient photocatalysis activities. Magnesium (Mg)-doped zinc oxide (ZnO) nanoparticles (NPs) has been synthesized by a one-step chemical low temperature (60 degrees C) co-precipitation method without further calcination and their photocatalytic performance for photodegradation of Methylene blue (MB) dye under the illumination of solar light is investigated. The crystal structure of the synthesized NPs is examined by X-ray diffraction (XRD). XRD data indicates a slight shift towards higher 2 theta angle in Mg-doped samples as compared to the pure ZnO NPs which suggest the incorporation of Mg2+ into ZnO crystal lattice. X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometer and cathodoluminescence (CL) spectroscopy, were used to study electronics, and optical properties, respectively. The XPS analysis confirms the substitution of the Zn2+ by the Mg2+ into the ZnO crystal lattice in agreement with the XRD data. The photocatalytic activities showed a significant enhancement of the Mg-doped ZnO NPs in comparison with pure ZnO NPs. Hole/radical scavengers were used to reveal the mechanism of the photodegradation. It was found that the addition of the Mg to the ZnO lattices increases the absorption of the hydroxyl ions at the surface of the NPs and hence acts as a trap site leading to decrease the electron-hole pair and consequently enhancing the photodegradation.

  • 18.
    Fowler, Scott
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Baravdish, Gabriel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Baravdish, George
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Compressed Sensing of Wireless Signals for Image Tensor Reconstruction2019Ingår i: IEEE Global Communications Conference: Signal Processing for Communications (Globecom2019 SPC), 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Use of wireless signal for identification of unknown object, or technology to see-through a wall to form an image, is gaining growing interest from various fields including law enforcement and military sectors, disaster management, or even in civilian sectors such as construction sites. The great challenge in the implementation of such technology is the stochastic disturbances on wireless signal which will result in a signal with missing samples. Compressive Sensing (CS) is a powerful tool for estimating the missing samples since it can find accurate solution to largely underdetermined linear wireless signals. However, sparse models like CS can also suffer from information loss dues to stochastic lossy nature of wireless, making CS not to have accurate information for reconstruction of a signal. In this paper, we developed a theoretical and experimental framework for the mapping of obstacles by reconstructing the wireless signal based on a sparse signal. We apply tensor format to perform the computations along each mode by relaxing the tensor constraints to obtain accurate results. The proposed framework demonstrates how to take 2D signals, formulate estimate signals and produce a 3D image location in a completely unknown area inside of the obstacle (wall).

  • 19.
    Fowler, Scott
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Baravdish, George
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Rudberg, Martin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Optimizing Compressed Sensing for seeing through walls based on Wireless Signals2019Ingår i: IEEE Symposium on Computers and Communications (ISCC), 2019, s. 1-6Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we developed a theoretical and experimental framework for the mapping of obstacles using WiFi, based on a small number of wireless channel samples. This is very challenging due to the numerous channel coefficients to be estimated over the time-varying channel and the channel estimation of a wireless signal transmission to be considered for compressive sampling. In a typical communication system, the signal is sampled at least twice at the highest frequency contained in the signal. However, this limits efficient ways to compress the signal, as it places a huge burden on sampling the entire signal while only a small number of the transform coefficients are needed to represent the signal. To tackle this problem, we will focused on a mathematical optimization problem for the most efficient compressed sensing method called $\ell_1$-norm, known as Basis Pursuit. Before optimizing the problem, the noise was removed from the signal, namely, multipath fading. Our experimental results show the improved performance in the number of iterations for obtaining a framework for the mapping of obstacles.

  • 20.
    Gardner, Anne
    et al.
    Univ Technol, Australia.
    Bernhard, Jonte
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Male, Sally
    Univ Western Australia, Australia.
    Turns, Jennifer
    Univ Washington, WA 98195 USA.
    Editorial Material: EJEE Editorial for Special Issue: Research Methodologies that link theory and practice2019Ingår i: European Journal of Engineering Education, ISSN 0304-3797, E-ISSN 1469-5898, Vol. 44, nr 1-2Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    n/a

  • 21.
    Gong, Shaofang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Xu, Xin
    Univ Elect Sci and Technol China, Peoples R China.
    Karlsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Broadside-Coupled Microstrip Lines as Low Loss Metamaterial for Microwave Circuit Design2019Ingår i: Wireless Communications & Mobile Computing, ISSN 1530-8669, E-ISSN 1530-8677, Vol. 2019, artikel-id 9249352Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The entire microwave theory is based on Maxwells equations, whereas the entire electronic circuit theory is based on Kirchhoffs electrical current and voltage laws. In this paper, we show that the traditional microwave design methodology can be simplified based on a broadside-coupled microstrip line as a low loss metamaterial. That is, Kirchhoffs laws are still valid in the microwave spectrum for narrowband signals around various designated frequencies. The invented low loss metamaterial has been theoretically analyzed, simulated, and experimentally verified in both time and frequency domains. It is shown that the phase velocity of a sinusoidal wave propagating on the low loss metamaterial can approach infinity, resulting in time-space shrink to a singularity as seen from the propagating wave perspective.

    Ladda ner fulltext (pdf)
    fulltext
  • 22.
    Hassan, Kahin Akram
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Liu, Yu
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Besançon, Lonni
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Johansson, Jimmy
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för klimatpolitisk forskning, CSPR.
    Rönnberg, Niklas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    A Study on Visual Representations for Active Plant Wall Data Analysis2019Ingår i: DATA, E-ISSN 2306-5729, Vol. 4, nr 2, artikel-id 74Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The indoor climate is closely related to human health, well-being, and comfort. Thus, an understanding of the indoor climate is vital. One way to improve the indoor climates is to place an aesthetically pleasing active plant wall in the environment. By collecting data using sensors placed in and around the plant wall both the indoor climate and the status of the plant wall can be monitored and analyzed. This manuscript presents a user study with domain experts in this field with a focus on the representation of such data. The experts explored this data with a Line graph, a Horizon graph, and a Stacked area graph to better understand the status of the active plant wall and the indoor climate. Qualitative measures were collected with Think-aloud protocol and semi-structured interviews. The study resulted in four categories of analysis tasks: Overview, Detail, Perception, and Complexity. The Line graph was found to be preferred for use in providing an overview, and the Horizon graph for detailed analysis, revealing patterns and showing discernible trends, while the Stacked area graph was generally not preferred. Based on these findings, directions for future research are discussed and formulated. The results and future directions of this research can facilitate the analysis of multivariate temporal data, both for domain users and visualization researchers.

    Ladda ner fulltext (pdf)
    A Study on Visual Representations for Active Plant Wall Data Analysis
  • 23.
    Hatamie, Amir
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten. Shvrif Univ Technol, Iran.
    Angizi, Shayan
    Shvrif Univ Technol, Iran.
    Kumar, Saurabh
    Indian Inst Sci, India; Delhi Technol Univ, India.
    Pandey, Chandra Mouli
    Delhi Technol Univ, India.
    Simchi, Abdolreza
    Shvrif Univ Technol, Iran.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Malhotra, Bansi D.
    Delhi Technol Univ, India.
    Review-Textile Based Chemical and Physical Sensors for Healthcare Monitoring2020Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 167, nr 3, artikel-id 037546Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The emergence of textile-based wearable sensors as light-weight portable devices to monitor desired parameters, has recently gained much interest and has led to the development of flexible electronics on non-rigid substrates. The flexible biosensors may result in improved sports performance, to monitor the desired bodies for injuries, improved clinical diagnostics and monitor biological molecules and ions in biological fluids such as saliva, sweat. In addition, they could help users with different types of disorders such as blindness. In this context, new composite and nanomaterials have been found to be promising candidates to obtain improved performance of the textile based wearable devices and to optimize the structures for intimate contact with the skin for better functionality. This review aims to provide the most recent cutting-edge information on emergence, fabrication, materials, and applications of chemical and physical flexible and stretchable textile-based (bio)sensors. Besides this, we discusss the recent key innovations and applications of textile-based sensors in healthcare.

    Ladda ner fulltext (pdf)
    fulltext
  • 24.
    Hezam, F. A.
    et al.
    Taiz Univ, Yemen; Univ Khartoum, Sudan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Mustafa, M. A.
    Univ Khartoum, Sudan.
    Synthesis, structural, optical and magnetic properties of NiFe2O4/MWCNTs/ZnO hybrid nanocomposite for solar radiation driven photocatalytic degradation and magnetic separation2020Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects, ISSN 0927-7757, E-ISSN 1873-4359, Vol. 592, artikel-id 124586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Novel multifunctional NiFe2O4/MWCNTs/ZnO hybrid nanocomposite has been successfully synthesized via the hydrothermal and the co-precipitation methods at 210 degrees C and 90 degrees C, respectively, to be used as a solar radiation driven photocatalytic material. The hybrid nanocomposite exhibits enhanced photocatalytic activity compared to NiFe2O4 and ZnO for decolorization of Methylene Blue (MB) dye -as a model pollutant - from aqueous solutions under solar radiation. Different complementary analytical tools were used to investigate the structural, optical and magnetic properties of the photocatalyst which possess good light response ability, photocatalytic stability, magnetic separation performance and reproducibility. The results from optical degradation confirmed the synergistic effect between the NiFe2O4, the ZnO and the MWCNTs. Suppressed recombination of electron-hole pairs mean more efficient charge separation and enhanced photocatalytic activity. The apparent rate constant (k(app)) of the MB decolorization for a duration of 300 min using NiFe2O4/MWCNTs/ZnO, NiFe2O4 and ZnO photocatalysts were found to be 0.00438 min(-1), 4.12857E(-4) min(-1) and 0.002 min(-1) respectively. The removal efficiency was also investigated for different pH values. Due to the magnetic properties of the nanocomposite, it was possible to separate it after degradation experiments and hence re-usability is possible. In view of the enhanced solar radiation driven photodegradation, the present composite can present a robust alternative as a solar radiation driven photocatalyst.

  • 25.
    Jaroudi, Rym
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Univ Tunis El Manar, Tunisia.
    Astroem, Freddie
    Heidelberg Univ, Germany.
    Johansson, Tomas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten. Aston Univ, England.
    Baravdish, George
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Numerical simulations in 3-dimensions of reaction-diffusion models for brain tumour growth2019Ingår i: International Journal of Computer Mathematics, ISSN 0020-7160, E-ISSN 1029-0265Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We work with a well-known model of reaction-diffusion type for brain tumour growth and accomplish full 3-dimensional (3d) simulations of the tumour in time on two types of imaging data, the 3d Shepp-Logan head phantom image and an MRI T1-weighted brain scan from the Internet Brain Segmentation Repository. The source term is such that we have logistic growth. These simulations are obtained using standard finite difference approximations with novel calculations to increase speed and accuracy. Moreover, biological background to the model, its well-posedness together with a variational formulation are given. The variational formulation enable the feasibility of different derivations and modifications of the model.

    Ladda ner fulltext (pdf)
    fulltext
  • 26.
    Karlsson, Magnus
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Carlsson, Hakan
    Combitech AB, Sweden.
    Idebro, Mats
    Combitech AB, Sweden.
    Eek, Christoffer
    Combitech AB, Sweden.
    Microwave Heating as a Method to Improve Sanitation of Sewage Sludge in Wastewater Plants2019Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 142308-142316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For long-term sustainable agriculture, it is critical that we recycle nutrition to the soil that it came from. One important source is sewage sludge, but it must be sanitized from undesired pathogens before it may be spread on arable land. One common method today is deposition in about six months or more. Not only is such a long deposition-time costly due to the required storage-space, in the future usage of the method is likely to be more restricted from a regulatory perspective. To heat up sewage-sludge is a known method to speed up the sanitation process. However, achieving an even guaranteed temperature is not easy with porous sewage sludge. This is mainly due to the limited heat conductivity of the sludge. Microwaves at a frequency of 2.45 GHz have a penetration depth of a few centimeters and therefore has an advantage compared to other heating methods which only heats the surface. In the proposed system, the sewage sludge is continuously processed through a series of microwave cavities. The pathogen removal effectiveness was studied for different exposure settings, e.g., conveyor speed and applied microwave power in each cavity.

    Ladda ner fulltext (pdf)
    fulltext
  • 27.
    Liu, Yu
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    A Data-centric Internet of Things Framework Based on Public Cloud2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The pervasive application of Internet of Things (IoT) has been seen in many aspects in human daily life and industrial production. The concept of IoT originates from traditional machine-to-machine (M2M) communications which aimed at solving domain-specific and applicationspecific problems. Today, the rapid progress of communication technologies, the maturation of Internet infrastructures, the continuously reduced cost of sensors, and emergence of more open standards, have witnessed the approaching of the expected IoT era, which envisions full connectivity between the physical world and the digital world via the Internet protocol. The popularity of cloud computing technology has enhanced this IoT transform, benefiting from the superior computing capability and flexible data storage, let alone the security, reliability and scalability advantages.

    However, there are still a series of obstacles confronted by the industry in deployment of IoT services. First, due to the heterogeneity of hardware devices and application scenarios, the interoperability and compatibility between link-layer protocols, sub-systems and back-end services are significantly challenging. Second, the device management requires a uniform scheme to implement the commissioning, communication, authorization and identity management to guarantee security. Last, the heterogeneity of data format, speed and storage mechanism for different services pose a challenge to further data mining.

    This thesis aims to solve these aforementioned challenges by proposing a data-centric IoT framework based on public cloud platforms. It targets at providing a universal architecture to facilitate the deployment of IoT services in massive IoT and broadband IoT categories. The framework involves three representative communication protocols, namely WiFi, Thread and Lo-RaWAN, to enable support for local, personal, and wide area networks. A security assessment taxonomy for wireless communications in building automation networks is proposed as a tool to evaluate the security performance of adopted protocols, so as to mitigate potential network flaws and guarantee the security. Azure cloud platform is adopted in the framework to provide device management, data processing and storage, visualization, and intelligent services, thanks to the mature cloud infrastructure and the uniform device model and data model. We also exhibit the value of the study by applying the framework into the digitalization procedure of the green plant wall industry. Based on the framework, a remote monitoring and management system for green plant wall is developed as a showcase to validate the feasibility. Furthermore, three specialized visualization methods are proposed and a neuron network-based anomaly detection method is deployed in the project, showing the potential of the framework in terms of data analytics and intelligence.

    Delarbeten
    1. A Data-Centric Internet of Things Framework Based on Azure Cloud
    Öppna denna publikation i ny flik eller fönster >>A Data-Centric Internet of Things Framework Based on Azure Cloud
    Visa övriga...
    2019 (Engelska)Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 53839-53858Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Internet of Things (IoT) has been found pervasive use cases and become a driving force to constitute a digital society. The ultimate goal of IoT is data and the intelligence generated from data. With the progress in public cloud computing technologies, more and more data can be stored, processed and analyzed in cloud to release the power of IoT. However, due to the heterogeneity of hardware and communication protocols in the IoT world, the interoperability and compatibility among different link layer protocols, sub-systems, and back-end services have become a significant challenge to IoT practices. This challenge cannot be addressed by public cloud suppliers since their efforts are mainly put into software and platform services but can hardly be extended to end devices. In this paper, we propose a data-centric IoT framework that incorporates three promising protocols with fundamental security schemes, i.e., WiFi, Thread, and LoRaWAN, to cater to massive IoT and broadband IoT use cases in local, personal, and wide area networks. By taking advantages of the Azure cloud infrastructure, the framework features a unified device management model and data model to conquer the interoperability challenge. We also provide implementation and a case study to validate the framework for practical applications.

    Ort, förlag, år, upplaga, sidor
    IEEE, 2019
    Nyckelord
    Internet of Things, Cloud computing, Protocols, Wireless fidelity, Broadband communication, Monitoring, Interoperability, framework, cloud, azure, IoT hub, thread, WiFi, lorawan
    Nationell ämneskategori
    Data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-156704 (URN)10.1109/ACCESS.2019.2913224 (DOI)000467047300001 ()
    Anmärkning

    Funding agencies:  Swedish Environmental Protection Agency; Norrkoping Fund for Research and Development, Sweden

    Tillgänglig från: 2019-05-10 Skapad: 2019-05-10 Senast uppdaterad: 2019-08-21
    2. A Taxonomy for the Security Assessment of IP-based Building Automation Systems: The Case of Thread
    Öppna denna publikation i ny flik eller fönster >>A Taxonomy for the Security Assessment of IP-based Building Automation Systems: The Case of Thread
    2018 (Engelska)Ingår i: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 14, nr 9, s. 4113-4123Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Motivated by the proliferation of wireless building automation systems (BAS) and increasing security-awareness among BAS operators, in this paper we propose a taxonomy for the security assessment of BASs. We apply the proposed taxonomy to Thread, an emerging native IP-based protocol for BAS. Our analysis reveals a number of potential weaknesses in the design of Thread. We propose potential solutions for mitigating several identified weaknesses and discuss their efficacy. We also provide suggestions for improvements in future versions of the standard. Overall, our analysis shows that Thread has a well-designed security control for the targeted use case, making it a promising candidate for communication in next generation BASs.

    Nationell ämneskategori
    Elektroteknik och elektronik
    Identifikatorer
    urn:nbn:se:liu:diva-148570 (URN)10.1109/TII.2018.2844955 (DOI)000443994500032 ()
    Anmärkning

    Funding agencies: Vinnova (Swedish Innovation Agency); Norrkoping Fund for Research and Development in Sweden; Swedish Civil Contingencies Agency (MSB) through the Cerces project

    Tillgänglig från: 2018-06-13 Skapad: 2018-06-13 Senast uppdaterad: 2019-08-21
    3. Active Plant Wall for Green Indoor Climate Based on Cloud and Internet of Things
    Öppna denna publikation i ny flik eller fönster >>Active Plant Wall for Green Indoor Climate Based on Cloud and Internet of Things
    Visa övriga...
    2018 (Engelska)Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 6, s. 33631-33644Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    An indoor climate is closely related to human health, well-being and comfort. Thus, indoor climate monitoring and management are prevalent in many places, from public offices to residential houses. Our previous research has shown that an active plant wall system can effectively reduce the concentrations of particulate matter and volatile organic compounds and stabilize the carbon dioxide concentration in an indoor environment. However, regular plant care is restricted by geography and can be costly in terms of time and money, which poses a significant challenge to the widespread deployment of plant walls. In this article, we propose a remote monitoring and control system that is specific to the plant walls. The system utilizes the Internet of Things technology and the Azure public cloud platform to automate the management procedure, improve the scalability, enhance user experiences of plant walls, and contribute to a green indoor climate.

    Ort, förlag, år, upplaga, sidor
    IEEE, 2018
    Nationell ämneskategori
    Data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-148850 (URN)10.1109/ACCESS.2018.2847440 (DOI)
    Tillgänglig från: 2018-06-20 Skapad: 2018-06-20 Senast uppdaterad: 2019-08-21
    4. A Study on Visual Representations for Active Plant Wall Data Analysis
    Öppna denna publikation i ny flik eller fönster >>A Study on Visual Representations for Active Plant Wall Data Analysis
    Visa övriga...
    2019 (Engelska)Ingår i: DATA, E-ISSN 2306-5729, Vol. 4, nr 2, artikel-id 74Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The indoor climate is closely related to human health, well-being, and comfort. Thus, an understanding of the indoor climate is vital. One way to improve the indoor climates is to place an aesthetically pleasing active plant wall in the environment. By collecting data using sensors placed in and around the plant wall both the indoor climate and the status of the plant wall can be monitored and analyzed. This manuscript presents a user study with domain experts in this field with a focus on the representation of such data. The experts explored this data with a Line graph, a Horizon graph, and a Stacked area graph to better understand the status of the active plant wall and the indoor climate. Qualitative measures were collected with Think-aloud protocol and semi-structured interviews. The study resulted in four categories of analysis tasks: Overview, Detail, Perception, and Complexity. The Line graph was found to be preferred for use in providing an overview, and the Horizon graph for detailed analysis, revealing patterns and showing discernible trends, while the Stacked area graph was generally not preferred. Based on these findings, directions for future research are discussed and formulated. The results and future directions of this research can facilitate the analysis of multivariate temporal data, both for domain users and visualization researchers.

    Ort, förlag, år, upplaga, sidor
    MDPI, 2019
    Nyckelord
    visualization; qualitative evaluation; temporal multivariate data; active plant walls, Visualisering; kvalitativ utvärdering; tidsvarierande multivariate data; active plant walls
    Nationell ämneskategori
    Data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-157027 (URN)10.3390/data4020074 (DOI)000475303500028 ()
    Tillgänglig från: 2019-05-23 Skapad: 2019-05-23 Senast uppdaterad: 2019-08-21Bibliografiskt granskad
    Ladda ner fulltext (pdf)
    fulltext
    Ladda ner (png)
    presentationsbild
  • 28.
    Liu, Yu
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Hassan, Kahin Akram
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Karlsson, Magnus
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Pang, Zhibo
    Corporate Research, ABB AB, Västerås, Sweden.
    Gong, Shaofang
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    A Data-Centric Internet of Things Framework Based on Azure Cloud2019Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 53839-53858Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Internet of Things (IoT) has been found pervasive use cases and become a driving force to constitute a digital society. The ultimate goal of IoT is data and the intelligence generated from data. With the progress in public cloud computing technologies, more and more data can be stored, processed and analyzed in cloud to release the power of IoT. However, due to the heterogeneity of hardware and communication protocols in the IoT world, the interoperability and compatibility among different link layer protocols, sub-systems, and back-end services have become a significant challenge to IoT practices. This challenge cannot be addressed by public cloud suppliers since their efforts are mainly put into software and platform services but can hardly be extended to end devices. In this paper, we propose a data-centric IoT framework that incorporates three promising protocols with fundamental security schemes, i.e., WiFi, Thread, and LoRaWAN, to cater to massive IoT and broadband IoT use cases in local, personal, and wide area networks. By taking advantages of the Azure cloud infrastructure, the framework features a unified device management model and data model to conquer the interoperability challenge. We also provide implementation and a case study to validate the framework for practical applications.

    Ladda ner fulltext (pdf)
    fulltext
  • 29.
    Liu, Yu
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Hassan, Kahin Akram
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Karlsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Weister, Ola
    Vertical Plants System Sweden AB, Norrrköping, Sweden.
    Gong, Shaofang
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Active Plant Wall for Green Indoor Climate Based on Cloud and Internet of Things2018Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 6, s. 33631-33644Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An indoor climate is closely related to human health, well-being and comfort. Thus, indoor climate monitoring and management are prevalent in many places, from public offices to residential houses. Our previous research has shown that an active plant wall system can effectively reduce the concentrations of particulate matter and volatile organic compounds and stabilize the carbon dioxide concentration in an indoor environment. However, regular plant care is restricted by geography and can be costly in terms of time and money, which poses a significant challenge to the widespread deployment of plant walls. In this article, we propose a remote monitoring and control system that is specific to the plant walls. The system utilizes the Internet of Things technology and the Azure public cloud platform to automate the management procedure, improve the scalability, enhance user experiences of plant walls, and contribute to a green indoor climate.

  • 30.
    Mahmood, Faraz
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Kazim, Jalil-ur-Rehman
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Karlsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Gong, Shaofang
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Ying, Zhinong
    CTO office Sony Ericsson Mobile Communications AB, Sweden.
    Decoupling techniques of compact and broadband MIMO antennas for handheld devices2012Ingår i: IEEE 6th European Conference on Antennas and propagation (EuCAP 2012), 2012, s. 1-5, artikel-id 1569525515Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents an innovative MIMO antenna system consisting of two broadband antennas combined with a 90° or 180° hybrid coupler. The antenna system is suitable for future MIMO systems due to its wide decoupled bandwidth (from 698 to 2700 MHz) covering 23 frequency bands of LTE. Enhanced antenna performance is achieved by radiator slitting and ground plane modification. Moreover, supplemental meandered line ground structures are utilized to miniaturize the antenna size. The low profile antenna with its wide impedance bandwidth, high efficiency, low correlation and quasi-omni directional radiation pattern is attractive for the existing and future 4G mobile communication devices. Simulated and measured results including input reflection, mutual coupling, correlation, and antenna efficiency is presented and analyzed.

  • 31.
    Mugheri, Abdul Qayoom
    et al.
    Univ Sindh Jamshoro, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Aftab, Umair
    Mehran Univ Engn and Technol, Pakistan.
    Abro, Muhammad Ishaq
    Mehran Univ Engn and Technol, Pakistan.
    Mallah, Arfana Begum
    Univ Sindh Jamshoro, Pakistan.
    Memon, Gulam Zuhra
    Univ Sindh Jamshoro, Pakistan.
    Khan, Humaira
    Univ Sindh Jamshoro, Pakistan.
    Abbasi, Mazhar Ali
    Univ Sindh, Pakistan.
    Halepoto, Imran Ali
    Univ Sindh, Pakistan.
    Chaudhry, Saleem Raza
    Univ Engn and Technol, Pakistan.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    An advanced and efficient Co3O4/C nanocomposite for the oxygen evolution reaction in alkaline media2019Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, RSC ADVANCES, Vol. 9, nr 59, s. 34136-34143Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The design of efficient nonprecious catalysts for the hydrogen evolution reaction (HER) or the oxygen evolution reaction (OER) is a necessary, but very challenging task to uplift the water-based economy. In this study, we developed a facile approach to produce porous carbon from the dehydration of sucrose and use it for the preparation of nanocomposites with cobalt oxide (Co3O4). The nanocomposites were studied by the powder X-ray diffraction and scanning electron microscopy techniques, and they exhibited the cubic phase of cobalt oxide and porous structure of carbon. The nanocomposites showed significant OER activity in alkaline media, and the current densities of 10 and 20 mA cm(-2) could be obtained at 1.49 and 1.51 V versus reversible hydrogen electrode (RHE), respectively. The impedance study confirms favorable OER activity on the surface of the prepared nanocomposites. The nanocomposite is cost-effective and can be capitalized in various energy storage technologies.

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  • 32.
    Mugheri, Abdul Qayoom
    et al.
    Univ Sindh, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Aftab, Umair
    Mehran Univ Engn and Technol, Pakistan.
    Bhatti, Adeel Liaquat
    Univ Sindh, Pakistan.
    Memon, Nusrat Naeem
    Univ Sindh, Pakistan.
    Memon, Jamil-ur-Rehman
    Univ Sindh, Pakistan.
    Abro, Muhammad Ishaque
    Mehran Univ Engn and Technol, Pakistan.
    Shah, Aqeel Ahmed
    NED Univ Engn Sci and Technol, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Hullio, Ahmed Ali
    Univ Sindh, Pakistan.
    Ibupoto, Zafar Hussain
    Univ Sindh, Pakistan.
    Efficient tri-metallic oxides NiCo2O4/CuO for the oxygen evolution reaction2019Ingår i: RSC ADVANCES, Vol. 9, nr 72, s. 42387-42394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, a simple approach was used to produce nonprecious, earth abundant, stable and environmentally friendly NiCo2O4/CuO composites for the oxygen evolution reaction (OER) in alkaline media. The nanocomposites were prepared by a low temperature aqueous chemical growth method. The morphology of the nanostructures was changed from nanowires to porous structures with the addition of CuO. The NiCo2O4/CuO composite was loaded onto a glassy carbon electrode by the drop casting method. The addition of CuO into NiCo2O4 led to reduction in the onset potential of the OER. Among the composites, 0.5 grams of CuO anchored with NiCo2O4 (sample 2) demonstrated a low onset potential of 1.46 V vs. a reversible hydrogen electrode (RHE). A current density of 10 mA cm(-2) was achieved at an over-potential of 230 mV and sample 2 was found to be durable for 35 hours in alkaline media. Electrochemical impedance spectroscopy (EIS) indicated a small charge transfer resistance of 77.46 ohms for sample 2, which further strengthened the OER polarization curves and indicates the favorable OER kinetics. All of the obtained results could encourage the application of sample 2 in water splitting batteries and other energy related applications.

  • 33.
    Niyobuhungiro, Japhet
    et al.
    Univ Rwanda, Rwanda.
    Setterqvist, Eric
    Univ Vienna, Austria.
    Åström, Freddie
    Heidelberg Univ, Germany.
    Baravdish, George
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    ITERATIVE TV MINIMIZATION ON THE GRAPH2019Ingår i: Communications in Mathematical Sciences, ISSN 1539-6746, E-ISSN 1945-0796, Vol. 17, nr 4, s. 941-968Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We define the space of functions of bounded variation (BV) on the graph. Using the notion of divergence of flows on graphs, we show that the unit ball of the dual space to BV in the graph setting can be described as the image of the unit ball of the space l(infinity) by the divergence operator. Based on this result, we propose a new iterative algorithm to find the exact minimizer for the total variation (TV) denoising problem on the graph. The proposed algorithm is provable convergent and its performance on image denoising examples is compared with the Split Bregman and Primal-Dual algorithms as benchmarks for iterative methods and with BM3D as a benchmark for other state-of-the-art denoising methods. The experimental results show highly competitive empirical convergence rate and visual quality for the proposed algorithm.

  • 34.
    Osman, Dalia Ahmed Mohammed
    et al.
    Minist Ind and Trade, Sudan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Mustafa, Mustafa Abbas
    Univ Khartoum, Sudan.
    Reduction of Energy Consumption in Cement Industry Using Zinc Oxide Nanoparticles2020Ingår i: Journal of materials in civil engineering, ISSN 0899-1561, E-ISSN 1943-5533, Vol. 32, nr 6, artikel-id 04020124Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study investigates the possibility of introducing zinc oxide nanoparticles into the cement raw mix so as to reduce the energy consumption and CO2 emissions during processing. Zinc oxide nanoparticles are prepared via a hydrothermal growth method using zinc acetate dihydrate and sodium hydroxide as precursors. The percentages of zinc oxide nanopowder added to the cement raw material was varied between 1% and 3%. The resulted clinker and cement samples were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), and compressive strength tests. It is concluded that the addition of 1% synthesized zinc oxide nanopowder into portland cement production improves the burnability of the cement raw mixture. A reduction of clinker temperature up to 1,300 degrees C, instead of the 1,450 degrees C-1,500 degrees C usually required, was achieved, thereby enabling a reduction in both energy consumption and greenhouse gas emissions. The 28-day strength is within the target design compressive strength of 42.5 N/mm(2). (c) 2020 American Society of Civil Engineers.

  • 35.
    Owais, Owais
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Karlsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Gong, Shaofang
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Circular Monopole Antenna Stability with Regard to Ground Plane Size2008Ingår i: Proc. of the 2008 International Symposium on Antenna and Propagation (ISAP'08), Taiwan, Oct. 27-30, 2008., 2008, s. 1-4, artikel-id 1645003Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wireless communications for short range and high data rate require wideband operation that necessitates the demand for miniaturized, low cost and low profile antennas. Miniaturized planar monopole antennas provide wide impedance bandwidth for wireless personal area network applications [1]. Different monopole shapes have been considered and a lot of research has been made to improve the bandwidth and reduce the size by changing the antenna shape [2]-[4]. The radiator part has been the main focus of research to find a shape that provides wide bandwidth [3]-[4], as well on studying how the ground plane affects the bandwidth of antennas. Wide bandwidth has been obtained by bevelling the radiator [5] and use of a modified ground plane [6]. Planar monopoles with parasitic elements and slots give also a wideband [7]. It has been documented that the finite size of the ground plane is an important factor for the antenna performance [8]. Planar monopoles have a benefit of being low cost and compatible to printed circuit board (PCB) allowing compact design. Since the ground plane is coplanar with the antenna, it necessitates that its stability should not change when integrated in PCB with different ground plane size of adjoining circuits. To avoid pre-tuning and achieve cost effectiveness, system development requires a stable planar monopole antenna that can be integrated without depreciation of its performance. This paper studies in detail the effect of ground plane dimension, width and length, on the stability of the coplanar monopole antenna, by changing the ground plane size while keeping feedline and feedap constant. The parametric investigation supported by simulation and experimental results is conducted in this paper to give insights to the stability issue that have not been reported before.

  • 36.
    Qayoom Mugheri, Abdul
    et al.
    Univ Sindh Jamshoro, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Aftab, Umair
    Mehran Univ Engn and Technol, Pakistan.
    Ishaq Abro, Muhammad
    Mehran Univ Engn and Technol, Pakistan.
    Chaudhry, Saleem Raza
    Univ Engn and Technol, Pakistan.
    Amaral, Luis
    Univ Lisbon, Portugal.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    Co3O4/ NiO bifunctional electrocatalyst for water splitting2019Ingår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 306Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of noble metal free and active bifunctional catalysts for water splitting in alkaline media is highly demanded but very challenging. Herein, synergetic effects developed between two nonprecious metal oxides, Co3O4 and NiO, are reported, with the resulting composite showing promising properties as a catalyst for alkaline water electrolysis. The activity of the composite material towards both the HER and the OER was enhanced and the dynamic potential decreased, as compared with its counterparts. Importantly, low Tafel slopes of 101 and 61 mVdec(-1) are found for the composite catalyst for OER and HER respectively. EIS measurements revealed a decreased impedance response of the composite dominated by the intermediate frequency relaxation, related to the adsorption of intermediates. Moreover, based on the structural features the improved catalytic activity of the composite is also due to high electroactive surface area, swift electron transfer kinetics, and excellent electrical chemical coupling between Co3O4 and NiO. (c) 2019 Elsevier Ltd. All rights reserved.

  • 37.
    Ryberg, Thomas
    et al.
    Department of Communication and Psychology, Aalborg universitet, Denmark.
    Davidsen, Jacob
    Department of Communication and Psychology, Aalborg universitet, Denmark.
    Bernhard, Jonte
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Knowledge Forms in Students' Collaborative Work: PBL as a Design for Transfer work2019Ingår i: Designing for situated knowledge transformation / [ed] Dohn, Nina Bonderup Hansen, Stig Børsen Hansen, Jens Jørgen, Abingdon, Oxon, UK: Routledge, 2019, s. 127-144Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    This chapter analyses selected video data from a long-term, collaborative problem-based project work conducted by groups of Architecture and Design students within the frame of the Aalborg PBL model. This pedagogical model is discussed in relation to the analytic framework for transfer developed in Chapters 2 and 3. Following that, the chapter zooms in on selected extracts of video data of students’ actual group work, which is analysed from the perspective of embodied interaction analysis. Through the use of this analytical perspective, the chapter draws out two themes: “Embodiment – the intimacy of talk, gestures and artefacts” and “The material, collective history of the group and the production of shared artefacts and practices”. In relation to the first theme, it is discussed how e.g. the bodily-material handling of a styrofoam model can be viewed as an example of ‘practical knowledge’ that transgresses a merely ‘communicative’ or ‘illustrative’ purpose and can be seen as a way of ‘building an argument’ within a design process and as participating in an ‘epistemic design game’. In relation to the second theme, this argument is extended to include the physical surroundings the students work in and it is argued that the students develop ‘practical knowledge’ as patterns of practice for organising their work, organising the studio and working with models. In the conclusion, this is discussed in relation to the Aalborg PBL model.

  • 38.
    Savoyant, A.
    et al.
    Aix Marseille Univ, France.
    Rollo, M.
    Aix Marseille Univ, France.
    Texier, M.
    Aix Marseille Univ, France.
    Elhadi Adam, Rania Elhadi
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Bernardini, S.
    Aix Marseille Univ, France.
    Pilone, O.
    Aix Marseille Univ, France.
    Margeat, O.
    Aix Marseille Univ, France.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Bertaina, S.
    Aix Marseille Univ, France.
    Light-induced high-spin state in ZnO nanoparticles2020Ingår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 31, nr 9, artikel-id 095707Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effects of white-light irradiation on similar to 15.nm diameter ZnO nanoparticles are investigated by means of electron paramagnetic resonance, near liquid-nitrogen and liquid-helium temperatures. Under dark conditions, usual core- and surface-defects are detected, respectively, at g = 1.960 and g = 2.003. Under white-light illumination, the core-defect signal intensity is strongly increased, which is to be correlated to the light-induced conductivitys augmentation. Beside, a four-lines structure appears, with the same gravity center as that of the surface defects. Simulations and intensity power-dependence measurements show that this four-line-structure is very likely to arise from a localized high spin S = 2, induced by light irradiation, and subjected to a weak axial anisotropy. At 85K, this high-spin state can last several hours after the light-irradiation removal, probably due to highly spin-forbidden recombination process. The possible excited resonant complexes at the origin of this signal are discussed. Other light-induced S = 1/2-like centers are detected as well, which depend on the nanoparticles growth conditions.

  • 39.
    Shah, Aqeel Ahmed
    et al.
    NED University of Engineering and Technology Karachi, Pakistan.
    Bhatti, Muhammad Ali
    University of Sindh Jamshoro, Sindh, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Chandio, Ali Dad
    NED University of Engineering and Technology Karachi, Pakistan.
    Channa, Iftikhar A.
    NED University of Engineering and Technology Karachi, Pakistan.
    Sahito, Ali Ghulam
    University of Sindh Jamshoro, Sindh, Pakistan.
    Chalangar, Ebrahim
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Nur, Omer
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik.
    Ibupoto, Zafar Hussain
    University of Sindh Jamshoro, Sindh, Pakistan.
    Facile synthesis of copper doped ZnO nanorods for the efficient photo degradation of methylene blue and methyl orange2019Ingår i: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, zinc oxide (ZnO) nanorods are doped with copper by low temperature aqueous chemical growth method using different concentrations of copper 5 mg, 10 mg, 15 mg and 20 mg and labeled as sample 1, 2, 3 and 4 respectively. The morphology and phase purity of nanostructures was investigated by scanning electron microscopy, and powder X-ray diffraction techniques. The optical characterization was carried out through UV–Vis spectrophotometer. The band gap of coper doped ZnO has brought reduction at 250–600 nm and it indicates the fewer time for the recombination of electron and hole pairs, thus enhanced photo degradation efficiency is found. ZnO exhibits nanorods like shape even after the doping of copper. The photo degradation efficiency for the two chronic dyes such as methyl orange MO and methylene blue MB was found to be 57.5% and 60% respectively for a time of 180 mints. This study suggests that the copper impurity in ZnO can tailor its photocatalytic activity at considerable rate. The proposed photo catalysts are promising and can be used for the waste water treatment and other environmental applications.

  • 40.
    Soomro, Razium Ali
    et al.
    Univ Sindh, Pakistan; Beijing Univ Chem Technol, Peoples R China; Univ Bristol, England.
    Kalwar, Nazar Hussain
    Shah Abdul Latif Univ Khairpur, Pakistan.
    Avci, Ahmet
    Selcuk Univ, Turkey.
    Pehlivan, Erol
    Selcuk Univ, Turkey.
    Hallam, Keith Richard
    Univ Bristol, England.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    In-situ growth of NiWO4 saw-blade-like nanostructures and their application in photo-electrochemical (PEC) immunosensor system designed for the detection of neuron-specific enolase2019Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 141, artikel-id UNSP 111331Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL(-1) of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples.

  • 41. Beställ onlineKöp publikationen >>
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Electrochemical water splitting based on metal oxide composite nanostructures2020Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The occurrence of available energy reservoirs is decreasing steeply, therefore we are looking for an alternative and sustainable renewable energy resources. Among them, hydrogen is considered as green fuel with a high density of energy. In nature, hydrogen is not found in a free state and it is most likely present in the compound form for example H2O. Water covers almost 75% of the earth planet. To produce hydrogen from water, it requires an efficient catalyst. For this purpose, noble materials such as Pt, Ir, and Ru are efficient materials for water splitting. These precious catalysts are rare in nature, very costly, and are restricted from largescale applications. Therefore, search for a new earth-abundant and nonprecious materials is a hot spot area in the research today. Among the materials, nanomaterials are excellent candidates because of their potential properties for extended applications, particularly in energy systems. The fabrication of nanostructured materials with high specific surface area, fast charge transport, rich catalytic sites, and huge ion transport is the key challenge for turning nonprecious materials into precious catalytic materials. In this thesis, we have investigated nonprecious nanostructured materials and they are found to be efficient for electrochemical water splitting. These nanostructured materials include MoS2-TiO2, MoS2, TiO2, MoSx@NiO, NiO, nickeliron layered double hydroxide (NiFeLDH)/Co3O4, NiFeLDH, Co3O4, Cu-doped MoS2, Co3O4- CuO, CuO, etc. The composition, morphology, crystalline structure, and phase purities are investigated by a wide range of analytical instruments such as XPS, SEM, HRTEM, and XRD. The production of hydrogen/oxygen from water is obtained either in the acidic or alkaline media. Based on the functional characterization we believe that these newly produced nanostructured materials can be capitalized for the development of water splitting, batteries, and other energy-related devices.

    Delarbeten
    1. Advanced Electrocatalysts for Hydrogen Evolution Reaction Based on Core-Shell MoS2/TiO2 Nanostructures in Acidic and Alkaline Media
    Öppna denna publikation i ny flik eller fönster >>Advanced Electrocatalysts for Hydrogen Evolution Reaction Based on Core-Shell MoS2/TiO2 Nanostructures in Acidic and Alkaline Media
    Visa övriga...
    2019 (Engelska)Ingår i: ACS APPLIED ENERGY MATERIALS, ISSN 2574-0962, Vol. 2, nr 3, s. 2053-2062Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Hydrogen production as alternative energy source is still a challenge due to the lack of efficient and inexpensive catalysts, alternative to platinum. Thus, stable, earth abundant, and inexpensive catalysts are of prime need for hydrogen production via hydrogen evolution reaction (HER). Herein, we present an efficient and stable electrocatalyst composed of earth abundant TiO2 nanorods decorated with molybdenum disulfide thin nanosheets, a few nanometers thick. We grew rutile TiO2 nanorods via the hydrothermal method on conducting glass substrate, and then we nucleated the molybdenum disulfide nanosheets as the top layer. This composite possesses excellent hydrogen evolution activity in both acidic and alkaline media at considerably low overpotentials (350 mV and 700 mV in acidic and alkaline media, respectively) and small Tafel slopes (48 and 60 mV/dec in acidic and alkaline conditions, respectively), which are better than several transition metal dichalcogenides, such as pure molybdenum disulfide and cobalt diselenide. A good stability in acidic and alkaline media is reported here for the new MoS2/TiO2 electrocatalyst. These results demonstrate the potential of composite electrocatalysts for HER based on earth abundant, cost-effective, and environmentally friendly materials, which can also be of interest for a broader range of scalable applications in renewable energies, such as lithium sulfur batteries, solar cells, and fuel cells.

    Ort, förlag, år, upplaga, sidor
    AMER CHEMICAL SOC, 2019
    Nyckelord
    hydrogen evolution reaction; MoS2; TiO2; catalyst; acidic; alkaline
    Nationell ämneskategori
    Annan kemiteknik
    Identifikatorer
    urn:nbn:se:liu:diva-163971 (URN)10.1021/acsaem.8b02119 (DOI)000462944700053 ()
    Anmärkning

    Funding Agencies|Knut & Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2016.0346]; Kempe Foundation [JCK-1606]; European Unions Horizon 2020 research and innovation programme [654002]

    Tillgänglig från: 2020-03-05 Skapad: 2020-03-05 Senast uppdaterad: 2020-05-14
    2. MoSx@NiO Composite Nanostructures: An Advanced Nonprecious Catalyst for Hydrogen Evolution Reaction in Alkaline Media
    Öppna denna publikation i ny flik eller fönster >>MoSx@NiO Composite Nanostructures: An Advanced Nonprecious Catalyst for Hydrogen Evolution Reaction in Alkaline Media
    Visa övriga...
    2019 (Engelska)Ingår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, nr 7, artikel-id 1807562Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The design of the earth-abundant, nonprecious, efficient, and stable electrocatalysts for efficient hydrogen evolution reaction (HER) in alkaline media is a hot research topic in the field of renewable energies. A heterostructured system composed of MoSx deposited on NiO nanostructures (MoSx@NiO) as a robust catalyst for water splitting is proposed here. NiO nanosponges are applied as cocatalyst for MoS2 in alkaline media. Both NiO and MoS2@NiO composites are prepared by a hydrothermal method. The NiO nanostructures exhibit sponge-like morphology and are completely covered by the sheet-like MoS2. The NiO and MoS2 exhibit cubic and hexagonal phases, respectively. In the MoSx@NiO composite, the HER experiment in 1 m KOH electrolyte results in a low overpotential (406 mV) to produce 10 mA cm(-2) current density. The Tafel slope for that case is 43 mV per decade, which is the lowest ever achieved for MoS2-based electrocatalyst in alkaline media. The catalyst is highly stable for at least 13 h, with no decrease in the current density. This simple, cost-effective, and environmentally friendly methodology can pave the way for exploitation of MoSx@NiO composite catalysts not only for water splitting, but also for other applications such as lithium ion batteries, and fuel cells.

    Ort, förlag, år, upplaga, sidor
    Wiley-VCH Verlagsgesellschaft, 2019
    Nyckelord
    alkaline media; electrolysis; MoSx@NiO composites
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:liu:diva-155574 (URN)10.1002/adfm.201807562 (DOI)000459719800018 ()2-s2.0-85059344786 (Scopus ID)
    Anmärkning

    Funding Agencies|Knut and Alice Wallenberg Foundation; Kempe Foundation; LTU Lab fund program; Generalitat de Catalunya [2017 SGR 327, JRM 2017 SGR 1246]; Spanish MINECO project [ENE2017-85087-C3]; Severo Ochoa Programme (MINECO) [SEV-2013-0295-17-1]; CERCA Programme/Generalitat de Catalunya

    Tillgänglig från: 2019-03-20 Skapad: 2019-03-20 Senast uppdaterad: 2020-05-14Bibliografiskt granskad
    3. An efficient bifunctional electrocatalyst based on a nickel iron layered double hydroxide functionalized Co3O4 core shell structure in alkaline media
    Öppna denna publikation i ny flik eller fönster >>An efficient bifunctional electrocatalyst based on a nickel iron layered double hydroxide functionalized Co3O4 core shell structure in alkaline media
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    2019 (Engelska)Ingår i: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 9, nr 11, s. 2879-2887Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Developing highly active nonprecious metal and binder free bifunctional electrocatalysts for water splitting is a challenging task. In this study, we used a simple strategy to deposit a nickel iron layered double hydroxide (NiFeLDH) onto cobalt oxide (Co3O4) nanowires. The cobalt oxide nanowires are covered with thin nanosheets of NiFeLDH forming a core shell structure. The Co3O4 nanowires contain the mixed oxidation states of Co2+ and Co3+, and the surface modification of Co3O4 nanowires has shown synergetic effects due to there being more oxygen defects, catalytic sites, and enhanced electronic conductivity. Further, the core shell structure of Co3O4 nanowires demonstrated a bifunctional activity for water splitting in 1 M KOH aqueous solution. From the hydrogen evolution reaction (HER), a current density of 10 mA cm - 2 is achieved at a potential of - 0.303 V vs. reversible hydrogen electrode (RHE). Meanwhile for the case of the oxygen evolution reaction (OER), a current density of 40 mA cm - 2 is measured at a potential of 1.49 V vs. RHE. Also, this electrocatalyst has shown a considerable long- term stability of 15 h for both the HER and the OER. Importantly, electrochemical impedance spectroscopy has shown that the NiFeLDH integration onto cobalt oxide exhibited around 3 fold decrease of charge transfer resistance for both the HER and the OER in comparison with pristine cobalt oxide films, which reveals an excellent electrocatalytic activity for both faradaic processes. All these results confirm that the proposed electrocatalyst can be integrated into an efficient water splitting system.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2019
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:liu:diva-158546 (URN)10.1039/c9cy00351g (DOI)000470710300013 ()2-s2.0-85066976848 (Scopus ID)
    Tillgänglig från: 2019-07-03 Skapad: 2019-07-03 Senast uppdaterad: 2020-05-14Bibliografiskt granskad
    4. Advanced Co3O4-CuO nano-composite based electrocatalyst for efficient hydrogen evolution reaction in alkaline media
    Öppna denna publikation i ny flik eller fönster >>Advanced Co3O4-CuO nano-composite based electrocatalyst for efficient hydrogen evolution reaction in alkaline media
    2019 (Engelska)Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 44, nr 48, s. 26148-26157Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In this study, we incorporate a copper impurity into (Co3O4) nanowires precursor that turn them into an active catalyst for the hydrogen evolution reaction in 1M KOH. The XRD and XPS results are in good agreement and confirmed the formation of Co3O4-CuO nano composite by wet chemical method. To date, the performance of hydrogen evolution reaction in alkaline for the composite catalyst is comparable or superior to cobalt oxide based HER electro-catalysts. The HER catalyst exhibits the lowest Tafel slope of 65 mVdec(-1) for the cobalt-based catalysts in alkaline media. A current density of 10 mA/cm(2) is achieved at a potential of 0.288 V vs reversible hydrogen electrode (RHE). The mixed transition metal oxide Co3O4-CuO based HER electro-catalyst is highly stable and durable. The EIS results demonstrates that HER is highly favorable on the Co3O4-CuO due to the relatively small charge transfer resistance (173.20 Ohm) and higher capacitance values (1.97 mF). (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

    Ort, förlag, år, upplaga, sidor
    PERGAMON-ELSEVIER SCIENCE LTD, 2019
    Nyckelord
    Composite metal oxide; Electro-catalyst; Hydrogen evolution reaction
    Nationell ämneskategori
    Annan kemiteknik
    Identifikatorer
    urn:nbn:se:liu:diva-162348 (URN)10.1016/j.ijhydene.2019.08.120 (DOI)000494890900004 ()
    Tillgänglig från: 2019-11-28 Skapad: 2019-11-28 Senast uppdaterad: 2020-05-14
    5. The chemically reduced CuO-Co3O4 composite as a highly efficient electrocatalyst for oxygen evolution reaction in alkaline media
    Öppna denna publikation i ny flik eller fönster >>The chemically reduced CuO-Co3O4 composite as a highly efficient electrocatalyst for oxygen evolution reaction in alkaline media
    Visa övriga...
    2019 (Engelska)Ingår i: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 9, nr 22, s. 6274-6284Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The fabrication of efficient, alkaline-stable and nonprecious electrocatalysts for the oxygen evolution reaction is highly needed; however, it is a challenging task. Herein, we report a noble metal-free advanced catalyst, i.e. the chemically reduced mixed transition metal oxide CuO-Co3O4 composite, with outstanding oxygen evolution reaction activity in alkaline media. Sodium borohydride (NaBH4) was used as a reducing agent for the mixed transition metal oxide CuO-Co3O4. The chemically reduced composite carried mixed valence states of Cu and Co, which played a dynamic role in driving an excellent oxygen evolution reaction process. The X-ray photo-electron spectroscopy (XPS) study confirmed high density of active sites in the treated sample with a large number of oxygen vacancies. The developed electrocatalyst showed the lowest overpotential of 144.5 mV vs. the reversible hydrogen electrode (RHE) to achieve the current density of 40 mA cm(-2) and remained stable for 40 hours throughout the chronoamperometry test at the constant potential of 1.39 V vs. RHE. Moreover, the chemically reduced composite was highly durable. Electrochemical impedance spectroscopy (EIS) confirmed the low charge transfer resistance of 13.53 ohms for the chemically reduced composite, which was 50 and 26 times smaller than that of Co3O4 and untreated CuO-Co3O4, respectively. The electrochemically active surface area for the chemically reduced composite was found to be greater than that for pristine CuO, Co3O4 and untreated pristine CuO-Co3O4. These findings reveal the possibility of a new gateway for the capitalization of a chemically reduced sample into diverse energy storage and conversion systems such as lithium-ion batteries and supercapacitors.

    Ort, förlag, år, upplaga, sidor
    ROYAL SOC CHEMISTRY, 2019
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:liu:diva-162507 (URN)10.1039/c9cy01754b (DOI)000496465000004 ()
    Tillgänglig från: 2019-12-13 Skapad: 2019-12-13 Senast uppdaterad: 2020-05-14
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  • 42.
    Tahira, Aneela
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    Vagin, Mikhail
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Aftab, Umair
    Mehran Univ Engn and Technol, Pakistan.
    Abro, Muhammad Ishaq
    Mehran Univ Engn and Technol, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    An efficient bifunctional electrocatalyst based on a nickel iron layered double hydroxide functionalized Co3O4 core shell structure in alkaline media2019Ingår i: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 9, nr 11, s. 2879-2887Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Developing highly active nonprecious metal and binder free bifunctional electrocatalysts for water splitting is a challenging task. In this study, we used a simple strategy to deposit a nickel iron layered double hydroxide (NiFeLDH) onto cobalt oxide (Co3O4) nanowires. The cobalt oxide nanowires are covered with thin nanosheets of NiFeLDH forming a core shell structure. The Co3O4 nanowires contain the mixed oxidation states of Co2+ and Co3+, and the surface modification of Co3O4 nanowires has shown synergetic effects due to there being more oxygen defects, catalytic sites, and enhanced electronic conductivity. Further, the core shell structure of Co3O4 nanowires demonstrated a bifunctional activity for water splitting in 1 M KOH aqueous solution. From the hydrogen evolution reaction (HER), a current density of 10 mA cm - 2 is achieved at a potential of - 0.303 V vs. reversible hydrogen electrode (RHE). Meanwhile for the case of the oxygen evolution reaction (OER), a current density of 40 mA cm - 2 is measured at a potential of 1.49 V vs. RHE. Also, this electrocatalyst has shown a considerable long- term stability of 15 h for both the HER and the OER. Importantly, electrochemical impedance spectroscopy has shown that the NiFeLDH integration onto cobalt oxide exhibited around 3 fold decrease of charge transfer resistance for both the HER and the OER in comparison with pristine cobalt oxide films, which reveals an excellent electrocatalytic activity for both faradaic processes. All these results confirm that the proposed electrocatalyst can be integrated into an efficient water splitting system.

    Ladda ner fulltext (pdf)
    fulltext
  • 43.
    Tahira, Aneela
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Ibupoto, Zafar Hussain
    Univ Sindh, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.