Fabrication of the ternary heterojunction Cd0.5Zn0.5S@UIO-66@g-C3N4 for enhanced visible-light photocatalytic hydrogen evolution and degradation of organic pollutants

novel ternary heterojunction Cd0.5Zn0.5S@UIO-66@g-C3N4 (Cd0.5Zn0.5S@UCN) has been prepared by the in situ hydrothermal and precipitation approach, which exhibits superior photocatalytic activity for H-2 generation and MO degradation under visible-light irradiation. The Cd0.5Zn0.5S@UCN30 composite shows the maximum photocatalytic H-2 production rate (1281.1 mu mol h(-1) g(-1)) that is about 32.9 and 2.7 times higher than UIO-66@g-C3N4 and pristine Cd0.5Zn0.5S, respectively. Besides, the Cd0.5Zn0.5S@UCN30 heterojunction indicates the superior degradation efficiency of MO (82%) in 120 min. The improved photocatalytic activity of the Cd0.5Zn0.5S@UCN heterostructure can be assigned to its large surface area, enhanced visible-light absorption ability and high-efficiency separation of photogenerated electron-hole pairs, which are proved by the results of photocurrent and EIS analyses. Moreover, the photocatalytic mechanism based on the ternary heterojunction Cd0.5Zn0.5S@UCN is discussed and the transfer and separation process of photogenerated electron-hole pairs is also proposed. This work demonstrates that a novel ternary noble-metal-free photocatalytic system could provide a scientific basis for the application in the field of energy production and pollution removal.