Functional integration of Ni–Mo electrocatalysts with Si microwire array photocathodes to simultaneously achieve high fill factors and light-limited photocurrent densities for solar-driven hydrogen evolution
Abstract
An n+p-Si microwire array coupled with a two-layer catalyst film consisting of Ni–Mo nanopowder and TiO_2 light-scattering nanoparticles has been used to simultaneously achieve high fill factors and light-limited photocurrent densities from photocathodes that produce H_2(g) directly from sunlight and water. The TiO_2 layer scattered light back into the Si microwire array, while optically obscuring the underlying Ni–Mo catalyst film. In turn, the Ni–Mo film had a mass loading sufficient to produce high catalytic activity, on a geometric area basis, for the hydrogen-evolution reaction. The best-performing microwire array devices prepared in this work exhibited short-circuit photocurrent densities of −14.3 mA cm^(−2), photovoltages of 420 mV, and a fill factor of 0.48 under 1 Sun of simulated solar illumination, whereas the equivalent planar Ni–Mo-coated Si device, without TiO_2 scatterers, exhibited negligible photocurrent due to complete light blocking by the Ni–Mo catalyst layer.
Additional Information
© Royal Society of Chemistry 2015. Received 05 Apr 2015, Accepted 13 Jul 2015; First published online 07 Aug 2015. This article is part of themed collection: Fundamentals and Applications of Inorganic Chemistry. Device modeling, fabrication and testing were supported by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub supported through the Office of Science of the U.S. Department of Energy under award number DE-SC004993. Development of the Ni–Mo nanopowder catalyst was supported by the National Science Foundation (NSF) Powering the Planet Center for Chemical Innovation (CHE-1305124) and by the Molecular Materials Research Center of the Beckman Institute at the California Institute of Technology. The authors acknowledge additional support by the Gordon and Betty Moore Foundation (GBMF1225). MRS acknowledges the Resnick Sustainability Institute for a graduate fellowship. JRM acknowledges the Department of Energy, Office of Science, for a graduate research fellowship and the Department of Energy, Office of Energy Efficiency and Renewable Energy, for a SunShot postdoctoral research award.Attached Files
Published - c5ee01076d.pdf
Supplemental Material - suppc5ee01076d1.pdf
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Additional details
- Eprint ID
- 59572
- Resolver ID
- CaltechAUTHORS:20150814-170845573
- Department of Energy (DOE)
- DE-SC004993
- NSF
- CHE-1305124
- Gordon and Betty Moore Foundation
- 1225
- Resnick Sustainability Institute
- Created
-
2015-08-15Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute, JCAP