Heterostructures of NiCo ₂ O ₄ Nanospheres and FeCoNi-LDH Nanosheets for Efficient Electrocatalytic Oxygen Evolution Reaction

The development of high-performance oxygen evolution reaction (OER) electrocatalysts with robust stability is crucial for enhancing the efficiency of electrolytic hydrogen generation. In this work, a heterojunction catalyst composed of NiCo2O4 and FeCoNi-LDH (denoted as FeCoNi-LDH@NiCo2O4) was constructed via a controllable interfacial engineering strategy that combines hydrothermal synthesis and electrodeposition. Through experimental characterization, it was revealed that the electronic reconstruction at the heterojunction interface optimized the electronic structure of the active sites and significantly reduced the energy barrier of the rate-determining step (RDS) for the OER. Concurrently, the layered structure of LDH provided abundant exposed active sites, and the high conductivity of nickel cobaltate facilitated rapid charge transfer. Their synergistic effect substantially enhanced the catalytic performance. The optimized catalyst required a low overpotential of only 164 mV and exhibited a Tafel slope of 91.88 mV dec–1 to achieve a current density of 10 mA cm–2 in 1.0 M KOH. Furthermore, it demonstrated outstanding stability for over 45 h. This work provides an innovative strategy for designing efficient heterojunction electrocatalysts for the oxygen evolution reaction.