Hole‐Doping Driven Electronic Structure Reconstruction Enables Dual‐Site Synergistic Regulation and Energy Barrier Balancing in NiFe ₂ O ₄ for Efficient Seawater Oxygen Evolution

Abstract Efficient oxygen evolution reaction (OER) in alkaline seawater electrolysis is crucial for sustainable hydrogen production, but it is hindered by sluggish kinetics and chloride‐induced corrosion. Herein, an Al‐doped NiFe ₂ O ₄ catalyst is reported with a hydrangea‐like morphology supported on NiFe foam (12.3% Al‐NiFe ₂ O ₄ ), in which hole doping induced by the heterovalent Al ³⁺ ‐for‐Ni ²⁺ substitution reconstructs the Ni/Fe electronic environments, driving dual‐site synergistic regulation and energy barrier balancing. Specifically, the Fe d‐band center upshifts to strengthen *OH/*O adsorption, while the Ni d‐band center downshifts to balance the reaction pathway and facilitate *OOH desorption. This complementary synergy significantly accelerates OER kinetics. Besides, Al ³⁺ incorporation tailors the morphology to increase the exposure of catalytically active sites, thereby improving catalytic performance. Furthermore, the robust Al─O bonds generated in the catalyst inhibit chloride adsorption, enhancing corrosion resistance. Consequently, 12.3% Al‐NiFe ₂ O ₄ achieves current densities of 100 and 500 mA cm ⁻² at ultralow overpotentials of 232 and 257 mV, respectively, maintains stability for over 200 h at a current density of 100 mA cm ⁻² , and exhibits a high Faradaic efficiency of 94.8% in alkaline seawater. This study achieves synergistic functional differentiation of active sites through hole‐doping‐induced electronic reconstruction, offering a new design strategy for high‐performance seawater OER catalysts.