Partial Oxidation-Engineered Dendritic α-Fe2O3@Fe Photoanode: Enhanced Photoelectrochemical Water Splitting Performance and Pt-Modified Stability

As a renewable energy source, solar energy holds significant potential for addressing future energy and environmental challenges. Concurrently, hydrogen (H2), as a clean and renewable energy carrier, has garnered substantial attention. Photoelectrocatalytic water splitting to produce H2 represents an emerging green technology for converting solar energy into hydrogen energy, which has been highly valued by researchers. The key to advancing this technology lies in identifying photoelectrode materials with high catalytic activity and stability. In this study, dendritic α-Fe was synthesized via electrodeposition, and the photoelectrocatalytic performance of α-Fe2O3@Fe was enhanced through partial oxidation. This approach effectively addressed the issue of the short carrier transport distance in α-Fe2O3. Specifically, dendritic α-Fe2O3 was partially oxidized after annealing at 300°C for 6 h. The resulting partially oxidized α-Fe2O3@Fe exhibited a photocurrent that was 2.23 times higher than that of the fully oxidized counterpart. The influence of deposition potential on the photoelectrocatalytic performance was systematically explored, and an optimal deposition potential was identified. Additionally, surface modification with Pt was employed to further improve the photocatalytic performance of α-Fe2O3. After continuous operation for 2 h, the photocurrent of the surface-modified sample decreased by only 6.5%, indicating a substantial enhancement in stability.