MoS2-CdS heterojunction with enhanced photocatalytic activity: A first principles study

In this study, the electronic properties of the MoS2-CdS heterojunction were investigated based on density functional theory calculations within the Perdew-Burke-Ernzerhof and Heyd-Scuseria-Ernzerhof approximations. MoS2 serves as the photosensitizer in the MoS2-CdS heterojunction. Due to the proper band gap (2.11 eV) of the MoS2-CdS heterojunction even under irradiation by visible light, the electron in the MoS2-CdS heterojunction can readily transfer from the valence band maximum of CdS to the conduction band minimum of MoS2 and generate electron-hole pairs. A built-in potential of 0.45 eV can be generated in the heterojunction, so the electron-hole pairs may be separated efficiently in the heterojunction. In addition, the intensity of the optical absorption by the MoS2-CdS heterojunction is stronger than that by the monolayer CdS, thereby indicating that the MoS2-CdS heterojunction could be used as a hybrid photocatalyst in the future.