Theoretical study on photocatalytic hydrogen generation performance of two-dimensional GaN/ReS2 heterostructure

One effective way to solve energy crises and environmental problems is to find efficient photocatalysts to decompose water and produce hydrogen. In this work, the electronic structure and optical properties of GaN/ ReS2 van der Waals heterostructure were studied by first-principles calculations. The findings demonstrate that the GaN/ReS2 heterostructure is an indirect band gap semiconductor with a band gap of 1.901 eV, exhibiting stability and type II band alignment characteristics. This ensures the spatial separation of photoexcited electronhole pairs. At the heterostructure interface, a minor built-in electric field extends from the charge depletion layer of GaN to the charge accumulation layer of ReS2. Moreover, the heterostructure's visible light absorption coefficient is significantly enhanced compared to a single two-dimensional material. These calculations suggest that the GaN/ReS2 heterostructure holds potential as a photocatalytic material, offering theoretical guidance for future experimental research.