Strategies to initiate and control the nucleation behavior of bimetallic nanoparticlesShow others and affiliations
2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 24, p. 8149-8156Article in journal (Refereed) Published
Abstract [en]
In this work we report strategies to nucleate bimetallic nanoparticles (NPs) made by gas phase synthesis of elements showing difficulty in homogeneous nucleation. It is shown that the nucleation assisted problem of bimetallic NP synthesis can be solved via the following pathways: (i) selecting an element which can itself nucleate and act as a nucleation center for the synthesis of bimetallic NPs; (ii) introducing H-2 or CH4 as an impurity/trace gas to initiate nucleation during the synthesis of bimetallic NPs. The latter can solve the problem if none of the elements in a bimetallic NP can initiate nucleation. We illustrate the above mentioned strategies for the case of Mg based bimetallic NPs, which are interesting as hydrogen storage materials and exhibit both nucleation and oxidation issues even under ultra-high vacuum conditions. In particular, it is shown that adding H2 in small proportions favors the formation of a solid solution/alloy structure even in the case of immiscible Mg and Ti, where normally phase separation occurs during synthesis. In addition, we illustrate the possibility of improving the nucleation rate, and controlling the structure and size distribution of bimetallic NPs using H-2/CH4 as a reactive/nucleating gas. This is shown to be associated with the dimer bond energies of the various formed species and the vapor pressures of the metals, which are key factors for NP nucleation.
Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY , 2017. Vol. 9, no 24, p. 8149-8156
National Category
Inorganic Chemistry
Identifiers
URN: urn:nbn:se:liu:diva-139275DOI: 10.1039/c7nr00916jISI: 000403943600012PubMedID: 28580986OAI: oai:DiVA.org:liu-139275DiVA, id: diva2:1120983
Note
Funding Agencies|Netherlands Institute of Fundamentals Research for Materials (FOM); Department of Science and Technology (DST), India through the DST INSPIRE Faculty programme; Swedish Research Council [621-2012-4359, 622-2008-405]; Knut and Alice Wallenberg Foundation
2017-07-072017-07-072017-07-07