Kinetic Competition between Water-Splitting and Photocorrosion Reactions in Photoelectrochemical Devices

Semiconductor photocorrosion is a major challenge for the stability of photoelectrochemical water-splitting devices. Usually, photocorrosion is studied on the basis of thermodynamic aspects, by comparing the redox potentials of water to the self-decomposition potentials of the semiconductor or analyzing the equilibrium phases at given electrolyte conditions. However, that approach does not allow for a prediction of the decomposition rate of the semiconductor or the branching ratio with the redox reaction. A kinetic model has been developed to describe detailed reaction mechanisms and investigate competition between water-splitting and photocorrosion reactions. It is observed that some thermodynamically unstable semiconductors should photocorrode in a few minutes, whereas others are expected to operate over a period of years as a result of their extremely low photocorrosion current. The photostability of the semiconductor is mainly found to depend on surface chemical properties, catalyst activity, charge carrier density, and electrolyte acidity.


Published in:
Chemsuschem, 12, 9, 1984-1994
Year:
May 08 2019
Publisher:
Weinheim, WILEY-V C H VERLAG GMBH
ISSN:
1864-5631
1864-564X
Keywords:
Laboratories:




 Record created 2019-06-27, last modified 2019-08-30


Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)