Potential‐Regulated Phosphate Intercalation in Defective Nickel Hydroxyphosphate for Efficient Oxygen Evolution

ABSTRACT Controlling the transformation and structural incorporation of phosphorus‐containing species is critical for regulating the structure and catalytic performance of nickel‐based oxygen‐evolution catalysts, yet how catalyst‐growth conditions direct phosphorus species evolution and structural incorporation remains unclear. Herein, a potential‐directed in‐situ electrodeposition strategy is developed to regulate the evolution and incorporation behavior of phosphorus‐containing species, enabling the construction of phosphate‐intercalated nickel hydroxyphosphate on nickel foam (NF). Using hypophosphite as the phosphorus precursor, the deposition potential guides phosphorus‐containing species toward either Ni–P formation or phosphate intercalation into the α ‐Ni(OH) 2 framework through modulation of the local interfacial environment. The resulting phosphate‐intercalated nickel hydroxyphosphate (Ni 2 (PO 4 )(OH)/NF) preserves the hydroxide framework while inducing lattice expansion, local structural distortion, defect‐rich transport channels, and P–O–Ni coordination interactions. These structural and electronic features facilitate the formation and stabilization of high‐valence Ni oxyhydroxide active species during oxygen evolution. As a result, Ni 2 (PO 4 )(OH)/NF delivers an overpotential of 197 mV at 10 mA cm −2 in 1 M KOH and sustains stable electrolysis for over 1200 h. This work establishes a potential‐regulated strategy for coupling interfacial alkalization with phosphorus species transformation and phosphate intercalation, providing mechanistic guidance for constructing oxyanion‐intercalated electrocatalysts for efficient oxygen evolution.