Proposal of a novel two-dimensional ZnCS3 monolayer as an efficient hydrogen evolution electro-catalyst

Abstract

• The structure is stable at room temperature, and the conductivity is good, the material is cheap and easy to get. • The intrinsic active site, without the need to create an active site through vacancy defects. • Small strain can achieve ideal HER catalytic activity. The discovery of electro-catalysts for hydrogen evolution reaction (HER) with high activity and low cost has always attracted intensive attentions. Here, we propose a two-dimensional ZnCS 3 monolayer as a good HER electro-catalysts through first-principles calculations. The Gibbs free energy variation (ΔG H ) of ZnCS 3 is as low as 0.123 eV, and the good HER activity is mainly due to the active dangling bond on S atoms at the surface, as well as the metallic band characteristic and excellent electrical conductivities before and after the adsorption of H atom. Moreover, we find that ΔG H could be further tuned to be 0 by applying a small tensile strain of 1.7 %, which could be understood by the evolution of p-band center of the S atom under different strains. All these results suggest that ZnCS 3 nanosheet is a promising candidate of HER electro-catalysts.