In situ construction of γ-MoC/VN heterostructured electrocatalysts with strong electron coupling for highly efficient hydrogen evolution reaction

Rational design of high-efficiency, low-cost, and durable electrocatalysts for the hydrogen evolution reaction (HER) is imperative to clean hydrogen energy production by electrochemical water splitting. Herein, three-dimensional (3D) porous heterostructured γ-MoC/VN electrocatalysts are prepared from bulk V₂MoO₈ by in situ carbonization and nitridation. The γ-MoC/VN heterostructured catalyst has a large surface area, porous structure, enriched active sites consequently producing efficient and stable HER electrocatalytic properties as exemplified by a low overpotential of 86.6 mV at 10 mA cm⁻² and Tafel slope of 47.6 mV dec^-1. Density-functional theory calculation and X-ray photoelectron spectroscopy disclose strong electron interactions and redistribution of the density of state (DOS) in the γ-MoC/VN enabled by VN electron donation resulting in optimized H adsorption/desorption and enhanced HER catalytic activity. This work reveals a novel strategy to design porous heterostructured electrocatalysts with strong electron modulation for electrocatalytic water splitting and electrochemical energy conversion.