A DFT study of GaSe/AlN(ZnO) two-dimensional vdW heterostructure practiced as an encouraging photocatalyst for water splitting

Practicing two-dimensional semiconductor compounds as a photocatalyst could be a common way for watersplitting since the existence of the photogenerated holes-electron is greater than that within the 3D compounds. In any case, when the unique 2D semiconductor is utilized as a photocatalyst for the water-splitting, whole the photogenerated electron-holes will appear at the surface for the oxidation and decrease responses, individually, and they will confine every other on the corresponding surface. Subsequently, building the 2D vdW heterostructure can move forward this issue by isolating the photogenerated holes-electron at diverse sheets for the hydrogen advancement response and oxygen advancement response to break down water. In this framework, we investigate the 2D vdW GaSe/AlN and GaSe/ZnO heterostructures employing density functional theory. Our predictions show that the four stacking buildings all contain weak and the interface binding energies are negative, which implies that their interlayer couplings have a place in the vdW interaction and their arrangements are energetically favorable. Further, for GaSe/AlN vdW heterostructures characterized by type II band structure, showing the ability to continuously separate holes and electrons photogenerated. However, GaSe/ZnO vdW heterostructures are of type I band alignment. We have found that the vdW forces separating the interface of the heterostructure, which implies the heterostructure is designed by vdW synergy preferably of covalent bond. Moreover, band edge positions of GaSe, AlN, ZnO, and GaSe/AlN(ZnO) heterostructures satisfy the demand for the redox reactions of water splitting at pH= 0.