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

LaFeO₃ 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 LaFeO₃ as a high surface area, nanoporous photocathode. The resulting electrode generated a photocurrent density of 0.1 mA/cm² 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 a stable photocurrent generation with no sign of photocorrosion. Due to the poor catalytic nature of the LaFeO₃ surface for water reduction, photocurrent obtained for water reduction was not substantial. Furthermore, 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.