Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources. De-centralized production of hydrogen peroxide (H2O2) from water and oxygen of air is highly desirable for daily life and industry. We report an effective electrochemical refinery (e-refinery) for H2O2 by means of electrocatalysis-controlled comproportionation reaction (2(H)O + O -> 2(HO)), feeding pure water and oxygen only. Mesoporous nickel (II) oxide (NiO) was used as electrocatalyst for oxygen evolution reaction (OER), producing oxygen at the anode. Conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) drove the oxygen reduction reaction (ORR), forming H2O2 on the cathode. The reactions were evaluated in both half-cell and device configurations. The performance of the H2O2 e-refinery, assembled on anion-exchange solid electrolyte and fed with pure water, was limited by the unbalanced ionic transport. Optimization of the operation conditions allowed a conversion efficiency of 80%.

Increasing the electrochemical surface area of noble metal electrodes is vital for many applications, including catalysis and bioelectronics. Herein, a method is presented for obtaining porous noble metal thin films via reactive magnetron sputtering of noble metal oxides, MOx, followed by their reduction using chemical reducers or electrochemical current. Variation of reduction conditions yields a range of different electrochemical and morphological properties. This method for obtaining porous noble metals is rapid, facile, and compatible with microfabrication processes. The resulting metallic films are porous and have competitively high capacitance and low impedance.

The nervous system poses a grand challenge for integration with modern electronics and the subsequent advances in neurobiology, neuroprosthetics, and therapy which would become possible upon such integration. Due to its extreme complexity, multifaceted signaling pathways, and similar to 1 kHz operating frequency, modern complementary metal oxide semiconductor (CMOS) based electronics appear to be the only technology platform at hand for such integration. However, conventional CMOS-based electronics rely exclusively on electronic signaling and therefore require an additional technology platform to translate electronic signals into the language of neurobiology. Organic electronics are just such a technology platform, capable of converting electronic addressing into a variety of signals matching the endogenous signaling of the nervous system while simultaneously possessing favorable material similarities with nervous tissue. In this review, we introduce a variety of organic material platforms and signaling modalities specifically designed for this role as "translator" , focusing especially on recent implementation in in vivo neuromodulation. We hope that this review serves both as an informational resource and as an encouragement and challenge to the field.

There is a broad and growing interest in Bioelectronic Medicine, a dynamic field that continues to generate new approaches in disease treatment. The fourth bioelectronic medicine summit "Technology targeting molecular mechanisms" took place on September 23 and 24, 2020. This virtual meeting was hosted by the Feinstein Institutes for Medical Research, Northwell Health. The summit called international attention to Bioelectronic Medicine as a platform for new developments in science, technology, and healthcare. The meeting was an arena for exchanging new ideas and seeding potential collaborations involving teams in academia and industry. The summit provided a forum for leaders in the field to discuss current progress, challenges, and future developments in Bioelectronic Medicine. The main topics discussed at the summit are outlined here.

Optoelectronic neurostimulation is a promising, minimally invasive treatment modality for neuronal damage, in particular for patients with traumatic brain injury. In this work, a newly developed optoelectronic device, a so-called photocap, based on light-activated organic semiconductor structures with high spatial and temporal resolution is investigated. To prove and verify the feasibility of this new technology, a mathematical model was developed, simulating the electrical response of excitable cells to photocap stimulation. In the first step, a comprehensive technical review of the device concept was performed, building the basis for setting up the simulation model. The simulations demonstrate that photocaps may serve as a stimulation device, triggering action potentials in neural or cardiac cells. Our first results show that the model serves as a perfect tool for evaluating and further developing this new technology, showing high potential for introducing new and innovative therapy methods in the field of optoelectronic cell stimulation.

Electrocatalysis for energy‐efficient chemical transformations is a central concept behind sustainable technologies. Numerous efforts focus on synthesizing hydrogen peroxide, a major industrial chemical and potential fuel, using simple and green methods. Electrochemical synthesis of peroxide is a promising route. Herein it is demonstrated that the conducting polymer poly(3,4‐ethylenedioxythiophene), PEDOT, is an efficient and selective heterogeneous catalyst for the direct reduction of oxygen to hydrogen peroxide. While many metallic catalysts are known to generate peroxide, they subsequently catalyze decomposition of peroxide to water. PEDOT electrodes can support continuous generation of high concentrations of peroxide with Faraday efficiency remaining close to 100%. The mechanisms of PEDOT‐catalyzed reduction of O2 to H2O2 using in situ spectroscopic techniques and theoretical calculations, which both corroborate the existence of a chemisorbed reactive intermediate on the polymer chains that kinetically favors the selective reduction reaction to H2O2, are explored. These results offer a viable method for peroxide electrosynthesis and open new possibilities for intrinsic catalytic properties of conducting polymers.

Photochemical generation of hydrogen peroxide via oxygen reduction is a critical component of emerging sustainable energy conversion concepts. Light‐absorbing semiconductors as well as electrodes modified with sensitizers typically catalyze oxygen photoreduction to hydrogen peroxide. Here, it is reported that, in contrast to these heterogeneous systems, a homogeneous solution of a metal‐free organic dye can perform the whole catalytic cycle of hydrogen peroxide photoevolution itself. This cycle can proceed with simultaneous oxidation of various organic molecules as electron donors, or even water. In the three water‐soluble dyes that are experimented with, photoevolution of peroxide occurs favorably at neutral to basic pH. The reaction is first order with respect to dye concentration, and evidence implicates a single‐electron reduction pathway with superoxide as an intermediate. Photostability of the dyes over time correlates with increased oxidation potential of the molecule. The finding that hydrogen peroxide can be produced in aqueous solution with single fully organic molecules performing the entire photocatalytic cycle creates a new avenue for the peroxide carbon free energy cycle.

The organic electronic ion pump (OEIP) is an emerging bioelectronic technology for on-demand and local delivery of pharmacologically active species, especially targeting alkali ions, and neurotransmitters. While electrical control is advantageous for providing precise spatial, temporal, and quantitative delivery, traditionally, it necessitates wiring. This complicates implantation. Herein, we demonstrate integration of an OEIP with a photovoltaic driver on a flexible carrier, which can be addressed by red light within the tissue transparency window. Organic thin-film bilayer photovoltaic pixels are arranged in series and/or vertical tandem to provide the 2.5–4.5 V necessary for operating the high-resistance electrophoretic ion pumps. We demonstrate light-stimulated transport of cations, ranging in size from protons to acetylcholine. The device, laminated on top of the skin, can easily be driven with a red LED emitting through a 1.5-cm-thick finger. The end result of our work is a thin and flexible integrated wireless device platform.