Construction and Alkaline Hydrogen Evolution Performance of CoN/NiMoN Heterostructure

At present, countries all over the world are actively developing new clean energy sources. Hydrogen production through electrolysis of water is a sustainable clean energy technology with broad application prospects. In order to reduce energy consumption and improve the practicality of electrolysis technology, researchers have made great efforts to explore high-performance electrocatalysts. A novel CoN/NiMoN heterostructure electrocatalyst was designed by combining hydrothermal and electrodeposition methods, combined with ammonia heat treatment approach. Amorphous nanofibrous CoN was successfully loaded onto NiMoN nanorods. It is found that the electronic structure of NiMoN was changed after combining with CoN. The electrons transferred from Ni to Mo and N, which effectively regulated the electronic structure of the active sites on the surface of NiMoN. Furthermore, the formation of the CoN/NiMoN heterostructure increased the electrochemical active surface area and intrinsic activity of the catalytic sites, thereby further enhancing the catalytic performance. Compared with pristine NiMoN and NiMoO₄, the CoN-loaded NiMoN exhibited significantly improved hydrogen evolution reaction (HER) performance, with current densities at −0.5 V vs. RHE to be increased by 1.58 times and 4.66 times, respectively. The overpotentials at current densities of 10 and 100 mA·cm⁻² were only 48 and 226 mV, respectively. The catalytic performance of CoN/NiMoN is comparable with that of the commonly used noble metal catalysts.