Bifunctional electrocatalyst based on Ni₃Se₂/NiSe@NF: Fabrication and performance in electrocatalytic hydrogen and oxygen evolution

In order to solve the problems of high cost and low electrolytic efficiency of traditional catalysts and realize the development of large-scale green hydrogen production technology, an interfacial catalyst based on transition metal was constructed by structural design and synthesis optimization in this study. The Ni₃Se₂/NiSe@NF heterojunction bifunctional electrocatalyst with interface structure was prepared on a nickel foam (NF) substrate by a two-step hydrothermal method. The strong charge transfer at the heterogeneous interface of Ni₃Se₂/NiSe@NF effectively optimizes the electronic structure of Ni₃Se₂/NiSe@NF compared with the single interface (Ni₃Se₂@NF and NiSe@NF), thus increasing the activities of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The prepared Ni₃Se₂/NiSe@NF has an overpotential of 71 and 207 mV (10 mA·cm^-2) at 1 mol/L KOH, respectively, and has impressive stability (no significant degradation within 500 h). In addition, when the current density is 10 mA·cm^-2, the current of the monolithic water decomposition electrolyzer with Ni₃Se₂/NiSe@NF as anode and cathode can be reduced to 1.52 V. Therefore, this study provides a new idea for the development of low-cost and high-stability catalysts for water electrolysis, which is expected to accelerate the integration of green hydrogen preparation and renewable energy systems, and help realize the goal of “dual-carbon”.