Volume 215, 2019

Light induced formation of a surface heterojunction in photocharged CuWO4 photoanodes

Abstract

Photocharging has recently shown the ability to significantly improve the performance of several metal oxide photoanodes, similar to the enhancements achieved with co-catalysts and passivation overlayers. Herein, we demonstrate the effect of photocharging on CuWO4 photoanodes for the first time, with prolonged AM 1.5 illumination under open-circuit conditions. The photocharging treatment on CuWO4 samples doubled the photocurrent obtained at 1.23 VRHE. This enhancement is attributed to the light induced formation of a surface bound copper complex with the solution anion species in the electrolyte. This thin semiconducting copper borate layer forms a heterojunction with the CuWO4, improving the charge separation near the surface and thus suppressing the recombination of charge carriers in the space charge region. The striking similarities in photocharging of different metal oxide semiconductors highlights that the metal oxide semiconductor–electrolyte interface is more complex than previously understood. The formation of this time-dependent light induced surface layer should therefore be considered in all experimental studies on photo-electrochemistry with metal oxide semiconductor photoanodes.

Graphical abstract: Light induced formation of a surface heterojunction in photocharged CuWO4 photoanodes

Associated articles

Supplementary files

Article information

Article type
Paper
Submitted
16 نومبر 2018
Accepted
07 دسمبر 2018
First published
07 دسمبر 2018

Faraday Discuss., 2019,215, 175-191

Light induced formation of a surface heterojunction in photocharged CuWO4 photoanodes

A. Venugopal and W. A. Smith, Faraday Discuss., 2019, 215, 175 DOI: 10.1039/C8FD00179K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements