Interfacial engineering of a Co(OH)2/NiCo-LDH heterojunction toward efficient and durable bifunctional electrocatalysis in alkaline water electrolysis

To promote the industrial implementation of alkaline water electrolysis for hydrogen production, the development of bifunctional electrocatalysts with high activity and durability is highly desirable. Herein, a Co(OH) 2 /NiCo-LDH heterojunction was constructed on Ni foam from a sputtered Ni-Co nanoparticle precursor through a one-pot hydrothermal route. The heterojunction effectively alleviates the poor conductivity and aggregation tendency of transition metal hydroxides. Theoretical calculations and electrochemical analyses demonstrate that the interfacial coupling facilitates water adsorption and lowers the energy barrier for the formation of the key *OOH intermediate, thereby boosting catalytic activity and durability. In 1 M KOH, the catalyst exhibits low overpotentials of 284.7 mV for OER and 155.2 mV for HER, with Tafel slopes of 61.2 and 53.4 mV dec −1 , respectively, and retains high activity for over 100 h. This work offers a feasible strategy for designing efficient and durable bifunctional electrocatalysts.