Photocharged Fe₂TiO₅/Fe₂O₃ Photoanode for Enhanced Photoelectrochemical Water Oxidation

Photocharging is a novel and effective photoanode treatment for improving the photoelectrochemical water splitting performance. Here, a photocharged Fe2TiO5/Fe2O3 photoanode was prepared with a significantly increased photocurrent density. Furthermore, the photocharging effect could also be deactivated via a discharging treatment under dark conditions. By using X-ray absorption spectroscopy and electrochemical impedance spectroscopy, the photocharging effect was revealed to be attributed to the formation of Fe­(IV) intermediates at the interface to accelerate the water oxidation kinetics. The results offer a detailed understanding on the mechanism of the photocharging effect in hematite, which may help in the design of highly efficient water splitting catalysts