Ultrafine molybdenum carbide nanoparticles supported on nitrogen doped carbon nanosheets for hydrogen evolution reaction

Molybdenum carbides（Mo;C）/nitrogen doped carbon nanosheets（NCS） composites are synthesized via simple mixing melamine and ammonia molybdate, followed by a high-temperature treatment. Metal carbide nanoparticles with ultra-small size（13nm） are uniformly supported on nitrogen doped carbon nanosheets. The hydrogen evolution reaction（HER） is investigated in both 0.5 mol/L H;SO;and 1 mol/L KOH media. Mo;C/NCS-10（melamine/ammonia molybdate weight ratio of 10:1） exhibits excellent performance with a low overpotential of 130 mV in 0.5 mol/L H;SO;solution and 108 mVin 1mol/L KOH solution at the current density of 10 mA/cm;. The better electrocatalytic activity could be ascribed to Ndoped carbon nanosheets, small particle size, mesoporous structure, and large specific surface area,which could provide the large electrochemical active surface area and facilitate mass transport.