Electronic structure and photocatalytic mechanism of g-SiC/ MoSSe van der waals heterostructures: A first principles study

The two-dimensional MoSSe based heterostructures has attracted much attention due to its excellent physical and chemical properties. In this research, first principles study were used to investigate the stability, electronic structure and optical behavior of g-SiC/MoSSe vdW heterostructures, as well as the photocatalytic performance of the overall water splitting. This research found that the g-SiC/MoSSe vdW heterostructures was an indirect band gap semiconductor with a type II band alignment which indicated the reduction and oxidation reactions of water splitting were carried out in different layers. In addition, the 6.23 eV potential drop generated by the charges transfer in the interface region can effectively inhibit the photo-generated e-/h+ recombination which is beneficial to improve the carriers mobility and the existence lifetime. Significantly, the g-SiC/MoSSe vdW heterostructures has a relatively high optical absorption in the visible light region which can effectively utilize the solar energy comparing to g-SiC and MoSSe monolayers. At different pH of medium, the photocatalytic ability of g-SiC/MoSSe vdW heterostructures all satisfy the splitting of water. These fascinating properties indicate that g-SiC/ MoSSe vdW heterostructures can be used as an efficient photocatalysts and have extraordinary application prospects.