Unlocking\nFe(III) Ions Improving Oxygen Evolution\nReaction Activity and Dynamic Stability of Anodized Nickel Foam

Fe has been reported to play a crucial role in improving\nthe catalytic\nactivity and stability of Ni/Co-based electrocatalysts for the oxygen\nevolution reaction (OER), while the Fe effect remains intangible.\nHere, we design several experiments to identify the activity and stability\nimprovement using porous anodized nickel foam (ANF) as the electrode\nand 1.0 M KOH containing 1000 μM Fe­(III) ions as the electrolyte.\nSystematic investigations reveal that Ni sites serve as hosts to capture\nFe ions to create active FeNi-based intermediates on the surface of\nANF to improve the OER activity significantly, and Fe ions regulate\ncatalytic equilibrium and maintain the stability for a long time.\nThe system exhibits 242 and 343 mV overpotentials to reach 10 and\n1000 mA cm<sup>–2</sup> current densities and a robust stability\nof 360 h at an industrially suitable current density (1000 mA cm<sup>–2</sup>). This work expands insights into the Fe­(III) catalysis\neffect on the OER efficiency of Ni-based catalysts and provides an\neconomical and practical way to commercial application.