(Photo)electrocatalytic materials

Topic #1:  Development of (photo)electrocatalytic materials and electrode architectures

imis_paper
(left): Cross-sectional TEM image of a novel photoelectrode architecture based on an insulator-metal-insulator-semiconductor (IMIS) structure. This IMIS structure was found to greatly enhance the stability and charge transport properties compared to conventional metal-insulator-semiconductor (MIS) electrodes lacking the top overlayer. Details can be found in reference [2]. TEM image credit: Haiyan Tan.
 Central to the operation of PEC, electrolyzer, fuel cell, and PV electrolysis devices are electrocatalysts and photocatalysts, materials that must efficiently facilitate charge transfer processes across solid/solid and solid/electrolyte interfaces.Developing novel electrocatalytic and photoelectrochemical materials architectures for improved activity, stability, and selectivity in (photo)electrochemical processes is a major focus of our lab’s activities. A good example of our efforts in this area is a novel photoelectrode architecture based on insulator-coated metal nanoparticles (see image).[2] As shown in this publication, the presence of 1-10 nanometer thick silicon oxide (SiOx) overlayers significant enhance charge transfer between the Si photoelectrode and Pt nanoparticle catalysts while greatly improving photoelectrode stability. In more recent work,[1] our lab is using these SiOx layers as “nanomembranes” that can simultaneously prevent various modes of electrocatalyst degradation while introducing advanced catalytic functionalities through selective transport of reactants or products between the electrolyte and catalyst.

Publications

  1. N. Y. Labrador, E.L. Songcuan, C. De Silva, D. V. Esposito, “Hydrogen evolution performance of membrane coated electrocatalysts based on well-defined silica-coated platinum thin films” (manuscript submitted).
  2. N. Y. Labrador, X. Li, Y. Liu, J. T. Koberstein, R. Wang, H. Tan, T. P. Moffat, and D. V. Esposito, “Enhanced Performance of Si MIS Photocathodes Containing Oxide-Coated Nanoparticle Electrocatalysts”, Nano Letters, vol. 16, 6452-6459, 2016. Available for download at: http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b02909
  3. D.V. Esposito, Y. Lee, N.Y. Labrador, H. Yoon, P. Haney, A.A. Talin, V. Szalai, T.P. Moffat, “Deconvoluting the Influences of 3-D Structure on the Performance of Photoelectrodes for Solar-Driven Water Splitting”.  Sustainable Energy & Fuels, 2017, DOI: 10.1039/C6SE00073H.  Available for download here.
  4. D.V. Esposito, S.T. Hunt, Y. Kimmel, and J.G. Chen, “A New Class of Electrocatalysts for Hydrogen Production from Water Electrolysis: Metal Monolayers Supported on Low Cost Transition Metal Carbides.” Journal of the American Chemical Society, vol. 134,3025-3033, 2012.

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