Vanadium-Doped Heterointerfaced Ni₃N-MoO_x Nanosheets with Optimized H and H₂O Adsorption for Effective Alkaline Hydrogen Electrocatalysis

Nickel (Ni)-based materials represent a compelling avenue as platinum alternatives in the realm of alkaline hydrogen electrocatalysis. However, conventional nickel nitrides (Ni₃N) have long been hindered by sluggish hydrogen evolution kinetics in alkaline environments, owing to inadequate adsorption strengths of both hydrogen and water molecules. Herein, a novel approach is presented involving the design of vanadium (V)-doped Ni₃N/MoO_x heterogeneous nanosheets (V-Ni₃N@MoO_x), engineered to achieve optimized adsorption strengths for hydrogen evolution and oxidation reactions (HER/HOR). Theoretical insights underscore the superior catalytic performance of this composite, attributed to a synergistic interplay between unique V doping and the heterointerfaced structure. This synergistic effect not only fine-tunes the electronic structure, establishing an optimal d band center to mitigate proton over-bonding, but also ameliorates the energy barrier through enhanced H₂O dissociation capability. Consequently, V-Ni₃N@MoO_x manifests remarkable catalytic activities, evincing an overpotential of 56 mV at 10 mA cm^-2 for HER and an exchange current density of 1.91 mA cm^-2 for HOR in alkaline media. Notably, the stability assessment reveals the enduring performance of V-Ni₃N@MoO_x for HER/HOR, exhibiting no activity decay over extended operational durations. This study underscores the efficacy of heterogeneous interface modulation as a transformative strategy in designing Ni-based materials for alkaline hydrogen electrocatalysis.