Self-Improvement of Ti:Fe₂O₃ Photoanodes: Photoelectrocatalysis Improvement after Long-Term Stability Testing in Alkaline Electrolyte

Hematite photoanode is a widely accepted stable photoelectrode in a strong alkali solution, such as NaOH aqueous solution. However, no one systematically investigates the photoelectrochemical stability of hematite-based photoanodes. More importantly, there are some contradictory results about the stability of hematite photoanodes in the literature. Herein we investigate the long-term stability of a Ti doped hematite (Ti:Fe₂O₃) photoanode in 1.0 M NaOH under visible light. Ti:Fe₂O₃ photoanode exhibits the significant photocurrent enhancement and the cathodic shift of the onset potential after long-term working in a strong alkali solution. Detailed characterizations reveal that an FeOOH layer, which serves as cocatalyst for self-improvement of Ti:Fe₂O₃ photoanodes, is formed at the interface of the Ti:Fe₂O₃/electrolyte junction.