Enhanced Stability and Activity for Water Oxidation in Alkaline Media with Bismuth Vanadate Photoelectrodes Modified with a Cobalt Oxide Catalytic Layer Produced by Atomic Layer Deposition
Abstract
Atomic-layer deposition (ALD) of thin layers of cobalt oxide on n-type BiVO_4 produced photoanodes capable of water oxidation with essentially 100% faradaic efficiency in alkaline, pH = 13 electrolytes. By contrast, under the same operating conditions, BiVO_4 photoanodes without the Co oxide catalytic layer exhibited lower faradaic yields, of ca. 70%, for O_2 evolution and were unstable, becoming rapidly photopassivated. High numbers (>25) of ALD cycles of Co oxide deposition gave electrodes that displayed poor photoelectrochemical behavior, but 15–20 ALD cycles produced Co oxide overlayers ~1 nm in thickness, with the resulting photoelectrodes exhibiting a stable photocurrent density of 1.49 mA cm^(–2) at the oxygen-evolution potential and an open-circuit potential of 0.404 V versus the reversible hydrogen electrode, under 100 mW cm^(–2) of simulated air mass 1.5 illumination.
Additional Information
© 2013 American Chemical Society. Received: October 16, 2013; Accepted: November 21, 2013; Published: November 21, 2013. This work was supported through the Office of Science of the U.S. Department of Energy under award DE-SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. XPS and AFM data were collected at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. We thank Dr. Ragip Pala for helpful discussions.Attached Files
Supplemental Material - jz4022415_si_001.pdf
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Additional details
- Eprint ID
- 43303
- Resolver ID
- CaltechAUTHORS:20140110-084420760
- Department of Energy (DOE)
- DE-SC0004993
- Created
-
2014-01-10Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- JCAP