Controllable N Doped in Carbon Nanolayers@Mo2C Nanodots as Electrocatalyst Boosts High-Efficient Hydrogen Production

Mo2C is one of the promising alternatives to the precious metal catalyst for hydrogen evolution reaction (HER). However, it is still challenging to prepare highly dispersed Mo2C and prevent nanoparticles (NPs) from sintering during high-temperature carbonization. Herein, a strategy is proposed to realize dual purposes that confine the coalescence of Mo2C NPs and redistribute charge density by regulating N-doped contents. As-synthesized molybdenum carbide nanodots are well dispersed on the N-doped carbon nanolayers, and the size of Mo2C is uniform and less than 5 nm. The HER tests reveal that as-prepared Mo2C nanodots exhibit excellent electrocatalytic activity for HER and long-term stability. Theory calculation proves that optimizing N doping amount can tune hydrogen adsorption free energies and redistribute charge density. The present study provides insight into the impact of nitrogen doped in C/Mo2C and also a synthetic route to achieve heteroatom doping and size control for the synthesis of nanocatalysts beyond Mo2C.