Interfacial engineered Mo₂C/MoO₂ heterojunction electrocatalyst for efficient hydrogen evolution in alkaline brine

The sluggish reaction kinetics and insufficient active sites remain key challenges for transition metal carbide catalysts in the hydrogen evolution reaction under alkaline conditions. In this work, we successfully construct a Mo₂C/MoO₂ heterojunction on a nitrogen-doped carbon substrate, effectively regulating the electronic structure and surface properties. Moreover, the efficient interfacial electron transfer optimizes hydrogen adsorption energy, thus facilitating reaction kinetics and improving the catalytic activity. In alkaline and alkaline saltwater environments, this catalyst exhibits hydrogen evolution activity comparable to commercial Pt/C (overpotential of only 13/23 mV at 10 mA cm^-2) and stability lasting up to 300 hours. This work provides new insights into designing high-performance non-precious metal electrocatalysts through interfacial engineering, holding significant implications for advancing the industrialization of water electrolysis hydrogen production technology.