Mo₂C coated with Ni nanoparticles as the cathode catalyst towards efficient hydrogen evolution reaction: an...

Although Mo₂C and earth-abundant 3d transition metals are regarded as potential catalysts to replace noble metal catalysts for effective hydrogen evolution reaction, their large-scale application is still inhibited by their own defects. Here, a facile thermal treatment method for nonprecious metal catalysts is developed to prepare a porous Ni/Mo₂C composite catalyst. The loading density of Ni nanoparticles on the Mo₂C surface has an important effect on the activity of the catalyst. By optimizing the Ni doping ratio, the Ni-40/Mo₂C-17 sample exhibits the lowest onset overpotential and lowest overpotential at 10 mA cm^-2 in both acidic and alkaline electrolytes, compared to other reported Ni- and Mo₂C-based catalysts. In addition, theoretical calculations have also confirmed the synergistic effect between Ni nanoparticles and Mo₂C, which can balance the thermodynamics between H adsorption and desorption of H₂. This work provides an avenue for designing high-performance water-splitting catalytic materials using low-cost species, which exhibit excellent HER activity in a wide pH range.