High-throughput screening of transition metal doping and defect engineering on single layer SnS2 for the water splitting hydrogen evolution reaction

Abstract

Doping and defect engineering have been widely used to improve the hydrogen evolution reaction (HER) activity of catalysts. Herein, the improved HER activity of SnS₂ nanosheets was systematically investigated. With transition metal (TM) doping, the basal plane S atom can be significantly activated for the HER. The calculated hydrogen adsorption free energy (ΔG_H*) of V, Mn, Ni, and Tc@SnS₂ is close to 0 eV. Furthermore, the hollow site of these nanosheets can be easily activated after introducing a S vacancy and these materials need smaller cathode voltage to introduce a S vacancy than pristine SnS₂ nanosheets. Surprisingly, ΔG_H* can reach 0.06 eV for pristine SnS₂ nanosheets by introducing 4.17% S vacancy concentration, which is better than that of platinum (Pt) catalysts. In addition, a corrected p_z band center model with a new descriptor φ was proposed for the prediction of HER activity. Our work offers a good understanding of the effects of TM doping and defect engineering on the improvement of HER activity at the atomic level.