Interface Engineering in MOF-Derived NiOOH/FeOOH Heterostructures: Boosting OER Performance via Lattice Oxygen Redox...

Precisely modulating lattice oxygen redox to activate the lattice oxygen mechanism (LOM) is paramount for surmounting the constraints of the traditional adsorbate evolution mechanism (AEM) and maximizing the catalytic activity of the oxygen evolution reaction (OER). Herein, we employ an electrochemical reconstruction strategy leveraging a bimetallic MOF precursor (NiPP/NM88B), which undergoes self-optimized in situ transformation into a NiOOH/FeOOH active phase with dense heterointerfaces. The unsaturated metal sites generated at the interfaces elicit interfacial charge redistribution, fortifying Fe─O bond covalency and efficiently activating lattice oxygen to partake in the OER process. Concurrently, the reconstructed active phase synergistically optimizes the adsorption/desorption kinetics of ^*OOH intermediates at Fe and Ni sites, thereby achieving the synergistic effect of AEM and LOM to expedite catalytic dynamics. The catalyst attains current densities of 10 and 100 mA cm^-2 with low overpotentials of 235 and 285 mV, respectively, while retaining stability for over 500 h. In an anion exchange membrane water electrolyzer (AEMWE), the catalyst enables prolonged stability for over 400 h at 1 A cm^-2, manifesting substantial potential for practical deployment. This work not only establishes a universal MOF-derived paradigm for fabricating high-performance Ni-Fe electrocatalysts but also furnishes theoretical insights into regulating LOM through interface engineering.