Zinc-doped mesoporous MoC/Mo2C heterojunction electrocatalyst for efficient hydrogen evolution

Exploring efficient noble-metal free electrocatalysts for the hydrogen evolution reaction (HER) is one of the most promising pathways for facing the energy crisis. Herein, we present a method for preparing Zinc-doped mesoporous MoC/Mo₂C heterojunction electrocatalysts using a steam assisted carburization strategy. Using a steam limited range method, the mesoporous structure is successfully prepared while retaining Zn doping, and the formation of β-Mo₂C is induced through a tailored carburization reaction. The prepared α-MoC/β-Mo₂C heterojunction shows excellent alkaline hydrogen evolution reaction performance. Due to the synergistic and electronic effects at the α-MoC/β-Mo₂C interface, the prepared ZNDM-MoC/Mo₂C exhibits an overpotential of 69 mV at a current density of 10 mA/cm² in 1 M KOH. Moreover, it can maintain stability for over 100 h. Density functional theory (DFT) calculations prove that ZNDM-MoC/Mo₂C has the most suitable H_ads adsorption free energy (ΔG_H∗) and the lowest water dissociation energy barrier. This work elucidates the synthesis mechanism of ZNDM-MoC/Mo₂C. Furthermore, it proposes a novel strategy for developing high-performance molybdenum carbide HER catalysts, challenging commercial Pt/C benchmarks.