Insight into the Activity and Stability Behaviors of the PbCrO Film Photoanode during Solar Water Oxidation in Different Electrolytes.

Monoclinic PbCrO is an n-type semiconductor with a band gap of ∼2.2 eV, which has attracted research attentions as photoanode material for solar water splitting in recent years, but few works consider the correlation of PbCrO photoanodes' activity and stability with electrolytes. Herein, typical monoclinic PbCrO films were prepared by a drop-casting method and investigated as photoanodes for solar water splitting in sodium sulfate (NSO), phosphate-buffered saline (PBS), potassium bicarbonate (KHCO), sodium borate (NBO), and potassium hydrogen phthalate (KHP) aqueous electrolyte. The water oxidation activity of the PbCrO film photoanode was found to be closely related to the electrolyte, and a relatively higher activity was observed on the PbCrO photoanode in PBS and KHP. However, in the five types of electrolytes, the PbCrO film photoanode had unsatisfactory stability due to the presence of photocorrosion, composition transformation, and dissolution, posing a significant challenge to the application of PbCrO in solar water splitting. In the NaSO/KHP mixing electrolyte, improved and stable photocurrent can be achieved on the PbCrO film photoanode for the oxidation of SO into SO. The present work reveals the objective water splitting behaviors of the PbCrO film photoanode in typical electrolytes, which could provide helpful reference and act as a reminder for the research of PbCrO and similar photoanode materials.