Integrating Ni nanoparticles into MoN nanosheets form Schottky heterojunctions to boost its electrochemical performance for water electrolysis

Water electrolysis using wind and solar as power offers a sustainable and promising approach to produce hydrogen. Bifunctional catalysts can significantly simplify the electrolysis system and enhance the overall electrochemical efficiency. Herein, three-dimensional nanostructured Ni and MoN compounds (Ni-Mo-N) with Schottky heterojunctions on the surface are developed as bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). It is found that the solvents and pyrolysis temperature play a very important role in the formation of Ni-Mo-N with Schottky heterojunctions. The optimized Ni-Mo-N can deliver an overpotential of 125 mV (@100 mA cm−2 current density) in HER, which is approach to the Pt/C (20 wt%) (116 mV). Ni-Mo-N also exhibits high-performance in OER, comparable to RuO2. When Ni-Mo-N is assembled as cathode and anode for water electrolysis, at the cell voltage of 1.604 V the cell reaches the current density of 10 mA cm−2 with remarkable durability, making the Ni-Mo-N a promising bifunctional catalyst for water electrolysis.