Issue 7, 2016

Insight into the charge transfer in particulate Ta3N5 photoanode with high photoelectrochemical performance

Abstract

Charge separation is one of the most critical factors for generating solar fuels via photoelectrochemical water splitting, but it is still not well understood. This work reveals the fundamental role of charge transfer in photoanodes for achieving high charge separation efficiency. Specifically, we fabricated a particulate Ta3N5 photoanode by a bottom-up method. By improving the charge separation with refined necking treatment, the photocurrent is increased by two orders of magnitude. The charge separation efficiency (ηsep) is analyzed by dividing it into charge generation efficiency (Φgene) and transportation efficiency (Φtrans). Necking treatment is found to substantially improve the electron transfer. Transient photovoltage (TPV) measurements based on the Dember effect is used to confirm the benefit of necking treatment in improving the charge transportation. The superior electron transfer in the necked-Ta3N5 electrode is further evidenced by the facile electron exchange reaction with the ferri/ferrocyanide redox couple. Moreover, cobalt phosphate is found to promote both charge separation and surface reaction, resulting in a photocurrent of 6.1 mA cm−2 at 1.23 V vs. RHE, which is the highest response for a particulate photoanode.

Graphical abstract: Insight into the charge transfer in particulate Ta3N5 photoanode with high photoelectrochemical performance

Supplementary files

Article information

Article type
Edge Article
Submitted
18 Jan 2016
Accepted
16 Mar 2016
First published
16 Mar 2016
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2016,7, 4391-4399

Author version available

Insight into the charge transfer in particulate Ta3N5 photoanode with high photoelectrochemical performance

Z. Wang, Y. Qi, C. Ding, D. Fan, G. Liu, Y. Zhao and C. Li, Chem. Sci., 2016, 7, 4391 DOI: 10.1039/C6SC00245E

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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