Facile synthesis of transition metal carbide nanoparticles embedded in mesoporous carbon nanosheets for hydrogen evolution reaction

Transition metal carbides (TMC) modified by mesoporous carbon nanosheets (MCNSs) with high activity, fast electron/ion transfer and long durability are considered as promising electrocatalysts for hydrogen evolution reaction (HER). However, most current synthesis methods involve in multistep, long duration and low output. In this work, Cr₃C₂, WC and VC nanoparticles embedded in mesoporous carbon nanosheets (TMC-NPs@MCNSs) were fabricated via a template-free and time-saving route by solution combustion synthesis. All TMC-NPs@MCNSs displayed good electrocatalytic activity for HER, and the Tafel plots of Cr₃C₂-NPs@MCNS, VC-NPs@MCNS and WC-NPs@MCNS electrocatalysts were 85, 77 and 56 mV·dec⁻¹, respectively. WC-NPs@MCNSs exhibited lower Tafel slope and overpotentials of 137 mV at ŋ₁₀ (a current density of 10 mA·cm⁻²), which could be ascribed to mesoporous structure, smaller particles size and strong electron interaction between W and C that promoted electron/ion transfer, maintained the structure integrity and enhanced the HER activity.