Ion Irradiation Activated Catalytic Activity of MoSe_2 Nanosheet for High-Efficiency Hydrogen Evolution Reaction

摘要

Developing highly efficient, low cost, and stable electrocatalysts that work at alarge current density is crucial for upgrading the current industrialelectrochemical water splitting to produce H2. Molybdenum selenide (MoSe_2)is a promising 2D transition metal dichalcogenide (TMD), however, itsreported output is inadequate due to its inert basal plane. Herein, the catalyticactivity of MoSe_2 nanosheet arrays is activated by a novel and controllablemethod of He+ ion irradiation to introduce multiple vacancies simultaneouslyinto their inert basal planes. The vacancies activated MoSe_2 have improvedelectrocatalytic performance and stability with a minimum overpotential of90 mV at 10 mA cm~(?2), a Tafel slope of 49mV dec~(?1) and high stability of 650 hat the industry-level large current density of 1000 mA cm~(?2) compared toseveral hours for the pristine sample. The DFT results reveal that single Seand single Mo vacancies on the MoSe2 basal plane can efficiently increase theelectrical conductivity and reduce energy barriers for water dissociation andsubsequent proton adsorption, thus improving the electrocatalytic capability.This finding proves the application of ion beam in defect engineering foreffective hydrogen evolution in TMDs-based catalysts.