Photoelectrochemical Properties and Stability of Nanoporous p-Type LaFeO₃ Photoelectrodes Prepared by Electrodeposition

LaFeO 3 is a p-type oxide that has an ideal bandgap and band edge positions for overall solar water splitting. This study reports an electrochemical synthesis method to produce LaFeO 3 as a high surface area, nanoporous photocathode. The resulting electrode generated a photocurrent density of −0.1 mA/cm 2 at a potential as positive as 0.73 V vs RHE for photoelectrochemical oxygen reduction with a photocurrent onset potential very close to its flatband potential of 1.45 V vs RHE. Furthermore, without a protection layer, it showed stable photocurrent generation with no sign of photocorrosion. Due to the poor catalytic nature of the LaFeO 3 surface for water reduction, the photocurrent obtained for water reduction was not substantial. However, its photostability and its ability to achieve a photovoltage for water reduction greater than 1.2 V encourage further studies on doping to enhance electron–hole separation as well as interfacing appropriate hydrogen evolution catalysts.