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

ABSTRACT 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 Fe ₂ O ₃ 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 Fe ₂ O ₃ , while sulfur incorporation generates electron‐deficient metal sites. Specifically, the engineered interfacial bonds establish rapid charge transport highways from the Fe ₂ O ₃ 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.