Heteroatom-doped MoSe₂ Nanosheets with Enhanced Hydrogen Evolution Kinetics for Alkaline Water Splitting

Electrochemical water splitting for hydrogen generation is a vital part for the prospect of future energy systems, however, the practical utilization relies on the development of highly active and earth-abundant catalysts to boost the energy conversion efficiency as well as reduce the cost. Molybdenum diselenide (MoSe₂ ) is a promising nonprecious metal-based electrocatalyst for hydrogen evolution reaction (HER) in acidic media, but it exhibits inferior alkaline HER kinetics in great part due to the sluggish water adsorption/dissociation process. Herein, the alkaline HER kinetics of MoSe₂ is substantially accelerated by heteroatom doping with transition metal ions. Specifically, the Ni-doped MoSe₂ nanosheets exhibit the most impressive catalytic activity in terms of lower overpotential and larger exchange current density. The density functional theory (DFT) calculation results reveal that Ni/Co doping plays a key role in facilitating water adsorption as well as optimizing hydrogen adsorption. The present work paves a new way to the development of low-cost and efficient electrocatalysts towards alkaline HER.