Plasma-engineered MoS2 thin-film as an efficient electrocatalyst for hydrogen evolution reaction.

Herein, for the first time, we reported a general approach of plasma engineering to tune the surface properties and edge reactive sites for greatly improving HER (hydrogen evolution) activity of MoS2. We show that the Ar or O2 plasma can be used to generate a large number of physical and chemical defects in 2D crystals to modify the electronic properties and increase the number of active sites in MoS2. Electrocatalytic studies show that the plasma-treated MoS2 exhibits significantly enhanced electrocatalytic activity for HER.