Computational studies of doped tin disulphide monolayer for photoelectrochemical water splitting

Abstract

In this ab initio study, density functional theory, including a Hubbard U correction term (DFT+U), calculations were performed to investigate the photoelectrochemical (PEC) water splitting possibility of SnS2 monolayer. Initially, the thermodynamic stability and photocatalytic (PC) properties of pristine SnS2 were studied and it was found that it suffers poor electrical conductivity and the bottom of conduction band minimum (CBM) is below the reduction potential of H^(+/) H_2 level, limiting the PC performance. To improve performance for PEC water splitting, various doping strategies were performed on a large 5×5 SnS2 supercell. These doping strategies are: C adsorbed onto an interstitial position, C adsorbed on a S atom, C adsorbed on a Sn atom, C substituting a S atom and C substituting a Sn atom.