Core–Shell Heterostructure of NiFe LDH Nanosheets on Ni ₃ S ₂ Nanorods for Robust Oxygen Evolution

The development of cost-effective, efficient, and durable high-performance oxygen evolution reaction (OER) catalysts is a preferred strategy to promote green and sustainable hydrogen from renewable energy electrocatalytic water. Herein, a hierarchical Ni3S2@NiFe LDH/NF core–shell nanoarray on nickel foam is constructed via interfacial engineering, requiring an ultralow oxygen evolution overpotential of 203 mV at 10 mA cm–2 with a Tafel slope of 50.79 mV dec–1 and 50 h stability at 300 mA cm–2 in 1.0 M KOH. This breakthrough performance is attributed to synergistic effects: interfacial electron transfer from conductive Ni3S2 nanorods to NiFe LDH nanosheets optimizes the electronic states for accelerated OH– adsorption; hierarchical porosity enables superhydrophilicity and electrolyte penetration; operando studies confirm the lowered phase-transition potential for in situ NiOOH generation while maintaining bulk conductivity. This work provides a promising strategy for the design of OER catalysts with hierarchical heterostructured nanoarrays.