Abstract
Exploring economical, efficient, and stable electrocatalysts for the seawater hydrogen evolution reaction (HER) is highly desirable but is challenging. In this study, a Mo cation doped Ni(0.85)Se/MoSe(2) heterostructural electrocatalyst, Mo(x)-Ni(0.85)Se/MoSe(2), was successfully prepared by simultaneously doping Mo cations into the Ni(0.85)Se lattice (Mo(x)-Ni(0.85)Se) and growing atomic MoSe(2) nanosheets epitaxially at the edge of the Mo(x)-Ni(0.85)Se. Such an Mo(x)-Ni(0.85)Se/MoSe(2) catalyst requires only 110 mV to drive current densities of 10 mA cm(-2) in alkaline simulated seawater, and shows almost no obvious degradation after 80 h at 20 mA cm(-2). The experimental results, combined with the density functional theory calculations, reveal that the Mo(x)-Ni(0.85)Se/MoSe(2) heterostructure will generate an interfacial electric field to facilitate the electron transfer, thus reducing the water dissociation barrier. Significantly, the heteroatomic Mo-doping in the Ni(0.85)Se can regulate the local electronic configuration of the Mo(x)-Ni(0.85)Se/MoSe(2) heterostructure catalyst by altering the coordination environment and orbital hybridization, thereby weakening the bonding interaction between the Cl and Se/Mo. This synergistic effect for the Mo(x)-Ni(0.85)Se/MoSe(2) heterostructure will simultaneously enhance the catalytic activity and durability, without poisoning or corrosion of the chloride ions.