Enhanced Photocatalytic Activity of Two-Dimensional Polar Monolayer SiTe for Water-Splitting via Strain Engineering.

A two-dimensional (2D) polar monolayer with a polarization electric field can be used as a potential photocatalyst. In this work, first principle calculations were used to investigate the stability and photocatalytic properties of 2D polar monolayer SiTe as a potential promising catalyst in water-splitting. Our results show that the 2D polar monolayer SiTe possesses an indirect band gap of 2.41 eV, a polarization electric field from the (001) surface to the (001¯) surface, a wide absorption region, and a suitable band alignment for photocatalytic water-splitting. We also discovered that the photocatalytic activity of 2D polar monolayer SiTe could be effectively tuned through strain engineering. Additionally, strain engineering, particularly compressive strain in the range from -1% to -3%, can enhance the photocatalytic activity of 2D polar monolayer SiTe. Overall, our findings suggest that 2D polar monolayer SiTe has the potential to be a promising catalyst for photocatalytic water-splitting using visible light.