Tailoring Ni/Mo2C interfaces via sol–gel assisted confinement strategy for efficient and durable alkaline hydrogen evolution

Transition metals and carbides have attracted significant attention as electrocatalysts owing to their high electrical conductivity and strong hydrogen-binding affinity, which was also hindered by limited exposure of active sites and instability. Herein, we report a confined heterostructured catalyst—Ni/Mo 2 C nanoparticles embedded in a porous nitrogen-doped carbon sheets (PNCS)—constructed via the sol–gel synthesis with high-temperature annealing. The interfacial coupling between Ni and Mo 2 C modulated the electronic structure and facilitated faster charge transfer, while the PNCS stabilized the active sites by suppressing nanoparticle agglomeration. Alkaline HER measurements revealed that the Ni/Mo 2 C@PNCS (2:3) catalyst operated with merely 114 mV overpotential to reach 10 mA cm –2 with a Tafel slope of 63 mV dec –1 , indicating outstanding activity, and maintained robust stability over 100 hours of continuous operation. This work provided a viable strategy for engineering confined TM/TMC heterostructures and offers new insights into designing high-performance non-noble metal-based HER catalysts through interface-driven electronic modulation.