Cobalt and Yttrium Doping to Activate Dual‐Site Mechanism of Amorphous NiFeOOH for Large‐Current Water Electrooxidation

The difference in hydroxyl adsorption between Ni and Fe sites in NiFeOOH limits the efficient dual‐site synergistic mechanism (DSSM) during oxygen evolution reaction (OER). Here, a novel needle‐array electrodeposition is reported for the scalable and efficient fabrication of Co and Y co‐doped NiFeOOH catalyst. It achieves an ultralow overpotential of 270 mV at 1 A cm −2 with a small Tafel slope of 30.7 mV dec −1 . It maintains stable operation at 1 A cm −2 for 1500 hrs with 98 % initial potential retention. When integrated into a 25 cm 2 anion exchange membrane electrolyzer, the system only needs 2.13 V to achieve 1 A cm −2 . XPS, XAS, and DFT studies reveal that Co and Y dopants increase the Lewis acidity of Ni sites, enhancing * OH adsorption. Concurrently, the incorporation of large Y atoms induces lattice distortion and elongates Fe─O─M bonds, weakening * OH binding at Fe sites. This dual‐site modulation reduces adsorption disparity, activates NiFe dual‐active centers, and promotes the DSSM pathway, as confirmed by in situ ATR‐SEIRAS. The rate‐determining step energy is lowered to 1.71 eV, significantly outperforming the conventional AEM pathway (2.51 eV). This work provides dual‐site modulation into engineering high‐performance NiFe‐based OER catalysts for practical water electrolysis.