Vanadium Doping Promotes Hydrogen Desorption on MoN/Ni Composite for Enhanced Electrocatalytic Hydrogen Evolution

ABSTRACT The MoN/Ni composite has been recognized as an excellent electrocatalyst for hydrogen evolution reaction (HER) in water splitting due to its unique electronic structure. In this study, a V‐doped MoN/Ni composite was synthesized through a hydrothermal reaction followed by nitridation treatment. The optimized catalyst exhibits an overpotential of only 322.1 mV to achieve a current density of 100 mA·cm −2 in 0.5 M H 2 SO 4 electrolyte, along with a Tafel slope of 94.2 mV·dec −1 . Compared to the pure MoN‐Ni catalyst, these values represent reductions of 16.2% and 37.6%, respectively. Density functional theory (DFT) calculations reveal that the Gibbs free energy of hydrogen adsorption at Mo active sites increased from ‐0.18 eV to 0.06 eV after V doping. Furthermore, the projected density of states (PDOS) of Mo atoms indicates that V doping increases the electronic density near the Fermi level, thereby promoting hydrogen desorption. These findings demonstrate that V doping is an effective strategy for enhancing the HER performance of MoN/Ni electrocatalyst.