Activating and Stabilizing\nLattice Oxygen via Self-Adaptive\nZn–NiOOH Sub-Nanowires for Oxygen Evolution Reaction

Efficient and durable catalysts for the oxygen evolution\nreaction\nare essential for realizing the large-scale application of water electrolysis\ntechnologies. Here, we report a novel Zn-doped NiOOH subnanowires\n(Zn–NiOOH SNWs) catalyst synthesized via the electrochemical\nreconstruction of Zn–NiMoO<sub>4</sub> SNWs. The inclusion\nof Zn triggers a transition in the oxygen evolution reaction mechanism\nof NiOOH from the adsorbate evolution mechanism to the lattice oxygen\nmechanism, resulted from Zn’s adaptive adjustment of coordination\ntypes, which also improves the reaction energetics, thereby enhancing\nthe stability and activity. Furthermore, the subnanowire structure\nprovides further stabilization of the lattice oxygen in Zn–NiOOH,\npreventing its destructive dissolution. Remarkably, Zn–NiOOH\nSNWs display a current density of 10 mA cm<sup>–2</sup> with\nan overpotential of only 179 mV and maintain stable operation at 200\nmA cm<sup>–2</sup> for 800 h with minimal changes in overpotential,\nestablishing them as one of the most effective catalysts involving\nlattice oxygen for the alkaline oxygen evolution reaction. When utilized\nas the anode in an alkaline water electrolyzer, our Zn–NiOOH\nSNWs catalyst demonstrates stability exceeding 500 h under a water-splitting\ncurrent of 200 mA cm<sup>–2</sup>, indicating promising potential\nfor practical applications.