Understanding Photocharging Effects on Bismuth Vanadate.

Bismuth vanadate (BiVO) is a promising material for photoelectrochemical water oxidation. Recently, it has been shown that "photocharging" BiVO results in an improved water oxidation performance. However, the understanding of how BiVO is being improved has been lacking.

Understanding the origin of photoelectrode performance enhancement by probing surface kinetics.

Photoelectrochemical (PEC) water splitting holds the potential to meet the challenges associated with the intermittent nature of sunlight. Catalysts have often been shown to improve the performance of PEC water splitting, but their working mechanisms are not well understood. Using intensity modulated photocurrent spectroscopy (IMPS), we determined the rate constants of water oxidation and recombination at the surface of three different hematite-based photoanodes.