Two-dimensional ZnO/MoSe2 van der Waals heterostructure used as promising photocatalyst for water splitting: A DFT study

[Display omitted] •The ZnO/MoSe2 vdW heterostructure has a direct band gap of 1.556 eV for at the equilibrium configuration.•The presence of the 0% strain the band structure is more suitable for the CBM and the reduction potential and the VBM and the oxidation potential of hydrolysis at PH = 7, indicates more excellent photocatalytic performance for the ZnO/MoSe2 vdW heterostructures. The strain can reduce the band gap and improve the absorption coefficient of visible light.•The heterojunction and strain can improve visible light absorption, and improve the position of conduction band edge and valence band edge. The electronic properties of the ZnO monolayer supported on the surface of MoSe2 monolayer were studied by the DFT study. The results indicate that the ZnO/MoSe2 vdW heterostructre, a single layer of ZnO monolayer as an effective photosensitizer can effectively absorb visible light, and the excited electrons can be effectively injected from ZnO monolayer into MoSe2 monolayer, thereby achieving carrier separation. Because ZnO/MoSe2 vdW heterostructre can realize the separation of photogenerated electron-hole pairs. On this basis, we further designed a new type of ZnO/MoSe2 vdW heterostructre with a band gap of 1.556 eV, which is conducive to the absorption of visible light and the excitation of carriers. The relative position of the energy band of the ZnO/MoSe2 vdW heterostructre makes light excitation. The electrons can be injected from the conduction band of ZnO monolayer into the conduction band of MoSe2 monolayer, and their interface charge distribution is conducive to the separation of carriers at the interface.