Improving the catalytic activity for hydrogen evolution of monolayered SnSe(2(1−)(x)())S(2)(x) by mechanical strain

Exploring efficient electrocatalysts for hydrogen production with non-noble metals and earth-abundant elements is a promising pathway for achieving practical electrochemical water splitting. In this work, the electronic properties and catalytic activity of monolayer SnSe(2(1−)(x)())S(2)(x) (x = 0–1) under compressive and tensile strain were investigated using density functional theory (DFT) computations. The results showed SnSe(2(1−)(x)())S(2)(x) alloys with continuously changing bandgaps from 0.8 eV for SnSe(2) to 1.59 eV for SnS(2). The band structure of a SnSe(2(1−)(x)())S(2)(x) monolayer can be further tuned by applied compressive and tensile strain. Moreover, tensile strain provides a direct approach to improve the catalytic activity for the hydrogen evolution reaction (HER) on the basal plane of the SnSe(2(1−)(x)())S(2)(x) monolayer. SnSeS and SnSe(0.5)S(1.5) monolayers showed the best catalytic activity for HER at a tensile strain of 10%. This work provides a design for improved catalytic activity of the SnSe(2(1-)(x)())S(2)(x) monolayer.