Ultrafast self-heating synthesis of robust heterogeneous nanocarbides for high current density hydrogen evolution reaction
Chenyu Li, Zhijie Wang, Mingda Liu, Enze Wang, Bolun Wang, Longlong Xu, Kaili Jiang, Shoushan Fan, Yinghui Sun, Jia Li, Kai Liu
Abstract
Abstract Designing cost-effective and high-efficiency catalysts to electrolyze water is an effective way of producing hydrogen. Practical applications require highly active and stable hydrogen evolution reaction catalysts working at high current densities (≥1000 mA cm −2 ). However, it is challenging to simultaneously enhance the catalytic activity and interface stability of these catalysts. Herein, we report a rapid, energy-saving, and self-heating method to synthesize high-efficiency Mo 2 C/MoC/carbon nanotube hydrogen evolution reaction catalysts by ultrafast heating and cooling. The experiments and density functional theory calculations reveal that numerous Mo 2 C/MoC hetero-interfaces offer abundant active sites with a moderate hydrogen adsorption free energy ΔG H* (0.02 eV), and strong chemical bonding between the Mo 2 C/MoC catalysts and carbon nanotube heater/electrode significantly enhances the mechanical stability owing to instantaneous high temperature. As a result, the Mo 2 C/MoC/carbon nanotube catalyst achieves low overpotentials of 233 and 255 mV at 1000 and 1500 mA cm −2 in 1 M KOH, respectively, and the overpotential shows only a slight change after working at 1000 mA cm −2 for 14 days, suggesting the excellent activity and stability of the high-current-density hydrogen evolution reaction catalyst. The promising activity, excellent stability, and high productivity of our catalyst can fulfil the demands of hydrogen production in various applications.