Optoelectronic and Photocatalytic Properties of SiC and VXY (X?=?Cl, Br and Y?=?Se, Te) van der Waals Heterostructures

Recent investigations have demonstrated that transition metal dichalcogenides (TMDs) are excellent candidates for water-splitting photocatalysis to produce hydrogen energy, but they exhibit a high recombination rate of photogenerated charge carriers, which hinders their practical application. Constructing novel TMD-based van der Walls (vdW) heterostructures is a promising strategy to suppress charge recombination, providing an opportunity to uncover new photocatalysts with improved water-splitting efficiency. In this work, we investigate the structural, optoelectronic and photocatalytic properties of the most favorable stacking pattern of SiC-VXY (X = Cl, Br and Y = Se, Te) vdW heterostructures using first-principles calculations. The results indicate that SiC-VXY (X = Cl, Br and Y = Se, Te) vdW heterostructures exhibit an indirect bandgap with type II band alignments, which effectively separate photoexcited electron-hole pairs at the interface. Moreover, the band edge positions of SiC-VXY bilayer systems straddle the redox potential of water, indicating that these heterostructures have the potential to become efficient photocatalysts for water splitting. Our theoretical investigation provides certain basis for designing novel TMD-based water-splitting photocatalysts and can pave the path for future experiments.