Synergistic Reconstructionof Defect-Enriched NiFe-LDHHierarchical Structures toward Large-Current and Stable Oxygen EvolutionReaction

NiFe layered double hydroxide (LDH) is the benchmark electrocatalyst toward alkaline oxygen evolution reaction (OER), however, it remains a grand challenge to develop NiFe LDH catalysts with higher intrinsic catalytic activity and abundant active sites by a simple and facile method. In this study, a synergistic reconstruction approach is introduced to fabricate defect-enriched NiFe layered double hydroxide (<i>d</i>-NiFe LDH) with three-dimensional (3D) hierarchical structures. Through in situ synergistic reconstruction of molybdates and phytic acid ligands, rapid generation of <i>d</i>-NiFe LDH two-dimensional nanosheets on one-dimensional nanorods is achieved. The <i>d</i>-NiFe LDH displays elevated intrinsic catalytic activity, with the 3D hierarchical structures exposing a greater number of active sites. Leveraging these characteristics, the electrode demonstrates outstanding OER catalytic performance with minimal overpotentials of 204 and 282 mV to reach current densities of 10 and 500 mA cm^–2. Notably, this electrode maintains excellent stability for over 350 h at 500 mA cm^–2. When coupled with a NiMoN electrode in a two-electrode system, low voltages of 1.47 and 1.73 V are needed to achieve 10 and 500 mA cm^–2, respectively. The work paves a fresh doorway for developing defects and 3D structures to construct advanced electrocatalysts toward various catalytic communities beyond OER.