Jump to main content
Jump to site search

Issue 7, 2016
Previous Article Next Article

Photoelectrochemical water splitting using WO3 photoanodes: the substrate and temperature roles

Author affiliations

Abstract

The influence of a substrate on the performance of WO3 photoanodes is assessed as a function of temperature. Two samples were studied: WO3 deposited on a FTO glass and anodized on a tungsten foil. Current–voltage curves and electrochemical impedance spectroscopy measurements were used to characterize these samples between 25 °C and 65 °C. The photocurrent density increased with temperature for both samples and the onset potential shifted to lower potentials. However, for WO3/FTO, a negative shift of the dark current onset was also observed. The intrinsic resistivity of this substrate limits the photocurrent plateau potential range. On the other hand, this behavior was not observed for WO3/metal. Therefore, the earlier dark current onset observed for WO3/FTO was assigned to the FTO layer. The optimal operating temperatures observed were 45 °C and 55 °C for WO3/FTO and WO3/metal, respectively. For higher temperatures, the bulk electron–hole recombination phenomenon greatly affects the overall performance of WO3 photoanodes. The stability behavior was then studied at these temperatures over 72 h. For WO3/FTO, a crystalline-to-amorphous phase transformation occurred during the stability test, which may justify the current decrease observed after the aging period. The WO3/metal remained stable, maintaining its morphology and good crystallinity. Interestingly, the preferential orientation of the aged crystals was shifted to the (−222) and (222) planes, suggesting that this was responsible for its better and more stable performance. These findings provide crucial information for allowing further developments on the preparation of WO3 photoanodes, envisaging their commercial application in PEC water splitting cells.

Graphical abstract: Photoelectrochemical water splitting using WO3 photoanodes: the substrate and temperature roles

Back to tab navigation

Supplementary files

Article information


Submitted
09 Nov 2015
Accepted
20 Jan 2016
First published
20 Jan 2016

Phys. Chem. Chem. Phys., 2016,18, 5232-5243
Article type
Paper
Author version available

Photoelectrochemical water splitting using WO3 photoanodes: the substrate and temperature roles

P. Dias, T. Lopes, L. Meda, L. Andrade and A. Mendes, Phys. Chem. Chem. Phys., 2016, 18, 5232 DOI: 10.1039/C5CP06851G

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

Search articles by author

Spotlight

Advertisements