Biomass-derived nitrogen-doped carbon supported Mo/Mo2C heterojunctions with interfacial electronic-activated carbon matrix for efficient hydrogen evolution

Molybdenum carbide has emerged as a promising candidate for the hydrogen evolution reaction (HER) due to its Pt-like electronic properties and stability. However, it suffers from strong hydrogen adsorption and particle aggregation, limiting its catalytic efficiency. Herein, we present a facile one-step pyrolysis strategy using biomass-derived chitosan as a dual-functional carbon/nitrogen source to synthesize nitrogen-doped carbon-supported Mo/Mo 2 C heterojunctions. The chitosan-derived porous carbon matrix prevents nanoparticle agglomeration, while nitrogen doping enhances conductivity. Remarkably, theoretical and experimental analyses reveal that the active sites are not the heterojunctions themselves but the adjacent carbon matrix activated by interfacial electronic effects, achieving near-optimal hydrogen adsorption free energy (ΔG H* = 0.01 eV). The optimized catalyst demonstrates outstanding HER performance, requiring only 97.7 mV overpotential to deliver 10 mA cm - ² in alkaline media. This work provides a cost-effective synthesis method alongside novel design principles for high-performance non-precious metal HER catalysts.