In-situ self-disassembly-mediated hierarchical assembly strategy: Engineered ultrathin NiFe-LDH/MOF heterostructured nanosheet architectures for efficient electrocatalytic oxygen evolution reaction acceleration

In oxygen evolution reaction (OER) electrocatalysis, conventional NiFe-LDH suffers from poor performance due to interlayer stacking (masking active sites) and low intrinsic conductivity (charge transfer hysteresis). In order to overcome this bottleneck, a series of NiFe-LDH/MOF heterojunction electrocatalysts with self-supported hierarchical structures and varying iron contents were in-situ constructed on nickel foam via a simple hydrothermal method using an in-situ "self-dissociation-assembly" strategy. Among them, Ni 0.66 Fe 0.33 -LDH/MOF excelled, showing an overpotential as low as 232 mV at 50 mA cm -2 , surpassing some noble metal catalysts. Electrochemical tests and characterization results revealed that the performance enhancement originates from the heterojunction structure: Firstly, the interfacial coupling between the MOF and LDH provides efficient electron transport pathways. Secondly, the heterojunction induces the formation of oxygen vacancies and optimizes the electronic structure of the metal centers, thereby improving the reaction kinetics. This work provides new insights for designing high-performance non-precious metal OER electrocatalysts.