Efficient suppression of back electron/hole recombination in cobalt phosphate surface-modified undoped bismuth vanadate photoanodes
File(s)
Published version
Author(s)
Ma, Y
Le Formal, F
Kafizas, A
Pendlebury, S
Durrant, J
Type
Journal Article
Abstract
In this paper, we compared for the first time the dynamics of photogenerated holes in BiVO4 photoanodes with and without CoPi surface modification, employing transient absorption and photocurrent measurements on microsecond to second timescales. CoPi surface modification is known to cathodically shift the water oxidation onset potential; however, the reason for this improvement has not until now been fully understood. The transient absorption and photocurrent data were analyzed using a simple kinetic model, which allows quantification of the competition between electron/hole recombination and water oxidation. The results of this model are shown to be in excellent agreement with the measured photocurrent data. We demonstrate that the origin of the improvement of photocurrent onset resulting from CoPi treatment is primarily due to retardation of back electron/hole recombination across the space charge layer; no evidence of catalytic water oxidation via CoPi was observed.
Date Issued
2015-09-10
Date Acceptance
2015-09-08
Citation
Journal of Materials Chemistry A, 2015, 3 (41), pp.20649-20657
ISSN
2050-7496
Publisher
Royal Society of Chemistry
Start Page
20649
End Page
20657
Journal / Book Title
Journal of Materials Chemistry A
Volume
3
Issue
41
Copyright Statement
© 2015 the Authors. This article is licenced under a Creative Commons Attribution (CC BY) licence http://creativecommons.org/licenses/by/4.0/
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Publication Status
Published