The dual-defective SnS2 monolayers: promising 2D photocatalysts for overall water splitting

Abstract

Photocatalytic water splitting is a promising way to produce hydrogen fuel from solar energy. In this regard, the search for new photocatalytic materials that can efficiently split water into hydrogen is essential. Here, using first-principles simulations, we demonstrate that the dual-defective SnS₂ (Ni-SnS₂-V_S), by both single-atom nickel doping and sulfur monovacancies, becomes a promising two-dimensional photocatalyst compared with SnS₂. The Ni-SnS₂-V_S monolayer, in particular, exhibits a suitable band alignment that perfectly overcomes the redox potentials for overall water splitting. The dual-defective monolayer displays remarkable photocatalytic activity, a spatially separated carrier, a broadened optical absorption spectrum, and enhanced adsorption energy of H₂O. Therefore, the dual-defective SnS₂ monolayer can serve as an efficient photocatalyst for overall water splitting to produce hydrogen fuel. Furthermore, a novel dual-defect method can be an effective strategy to enhance the photocatalytic behavior of 2D materials; it may pave inroads in the development of solar-fuel generation.