Balancing Surface Passivation and Catalysis with Integrated BiVO_4/(Fe-Ce)O_x Photoanodes in pH 9 Borate Electrolyte
Abstract
The performance of oxygen-evolving photoanodes based on bismuth vanadate (BiVO_4) is critically determined by the surface coating. While these coatings passivate surface defects, transport photogenerated holes, protect against corrosion, and aid catalysis, their optimal composition changes with operating pH, thus affecting overall performance. We use high-throughput photoelectrochemistry methods to map photoanode performance to enable the discovery of optimal composition and loading of Ce-rich sputter-deposited (Fe–Ce)O_x overlayers on undoped BiVO_4 in pH 9 borate buffer electrolyte. The optimal composition is found to be 20% Fe and 80% Ce with an optimal Fe + Ce metal loading of 0.9 nmol mm^(–2). Analysis of the composition and loading dependence of (i) the photocurrent transients upon illumination toggling, (ii) stabilized photocurrent densities, and (iii) photogenerated hole-transfer efficiency reveals the confluence of phenomena that gives rise to the optimal performance yielding nearly perfect transfer efficiency over a narrow composition window.
Additional Information
© 2018 American Chemical Society. Received: August 17, 2018; Accepted: September 26, 2018; Published: September 26, 2018. This material is based upon work performed 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-SC0004993. Author Contributions: L.Z. and A.S. contributed equally to this work. The authors declare no competing financial interest.Attached Files
Supplemental Material - ae8b01377_si_001.pdf
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Additional details
- Alternative title
- Balancing Surface Passivation and Catalysis with Integrated BiVO4/(Fe-Ce)Ox Photoanodes in pH 9 Borate Electrolyte
- Eprint ID
- 90041
- Resolver ID
- CaltechAUTHORS:20180927-134054550
- Department of Energy (DOE)
- DE-SC0004993
- Created
-
2018-09-27Created from EPrint's datestamp field
- Updated
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2022-04-26Created from EPrint's last_modified field
- Caltech groups
- JCAP