In Situ Synthesis of Nanorod Arrays of Nickel–Molybdenum Nitrides as Stable Electrocatalysts for Hydrogen Evolution Reactions

The development of cheap and highly active electrocatalysts for efficient water splitting is crucial for the production of green hydrogen at a low cost. In this work, we proposed a two-step method including hydrothermal and nitridation reactions to in situ synthesize NiMoN nanorod arrays with abundant active sites and a fast electron transfer rate on nickel foam substrate. The optimal tailoring of the Ni/Mo ratio leads to a high concentration of active Mo 3+ species and suitable Ni doping content in the NiMoN catalyst, which shows superior hydrogen evolution reaction performance. The overpotentials at the current densities of 10 and 100 mA/cm 2 are only 20 and 46 mV, which are better than those of the most reported NiMoN-based catalysts and even the commercial benchmark material of Pt/C. Additionally, the electrocatalyst also shows excellent long-term stability after 24 h tests at densities of 10 and 100 mA/cm 2, possessing great potential for industrial applications for water splitting to produce hydrogen.