Activating NiFe Catalysts Decorated Hematite Photoanodes Via Simultaneous Phospho‐Sulfurization for Efficient and Stable Solar Water Splitting

Solar-driven photoelectrochemical (PEC) water splitting represents a promising approach for renewable energy conversion, yet its practical implementation remains constrained by sluggish interfacial charge transfer kinetics. Herein, we demonstrate a rational synchronous phospho-sulfurization strategy for NiFe catalyst decorated Fe₂O₃ photoanodes that significantly enhances charge transfer efficiency across both semiconductor/catalyst and catalyst/electrolyte interfaces. Systematic experiments and DFT calculations reveal that phosphorus mediated O─P─O interfacial bonding anchors the NiFe catalysts to the Fe₂O₃, while sulfur incorporation generates electron-deficient metal sites. Specifically, the engineered interfacial bonds establish rapid charge transport highways from the Fe₂O₃ layer to the phospho-sulfurization NiFe catalyst, while the optimized metal sites accelerate hole transfer kinetics to the electrolyte for efficient oxygen evolution reaction. Consequently, an expected photocurrent density of 2.72 mA·cm^-2 at 1.23 V_RHE was achieved, accompanied by a competitive long-term durability of 40 h. This work establishes a new paradigm for designing multifunctional photoanodes with atomically tailored interfaces for solar water splitting.