All-solid-state Z-scheme CdTe/TiO2 heterostructure photocatalysts with enhanced visible-light photocatalytic degradation of antibiotic waste water

Due to their high persistence and ecotoxicity, developing a green and efficient approach to remove antibiotic residuals from aquatic environments becomes a challenging task. Efficient, visible light-active and reusable semiconductor photocatalyst is a promising solution to address this issue. In this work, Z-scheme CdTe/TiO2 heterostructure photocatalysts were prepared by a hydrothermal method and the photocatalytic performance of as-prepared samples was evaluated by degradation of tetracycline hydrochloride (TC-H) under visible-light irradiation. The optimal performance was achieved for CdTe/TiO2 heterostructure photocatalyst grown at 120 °C, which can decompose 78% TC-H after 30 min irradiation. The improved photocatalytic performance can be ascribed to synergistic effects including excellent visible-light absorption, efficient charge separation and relatively high redox potentials of electrons and holes associated with Z-scheme charge transfer mechanism. The possible degradation byproducts and stability of CdTe/TiO2 heterostructures for TC-H degradation are also elucidated. This Z-scheme CdTe/TiO2 photocatalysts may present a new strategy for degradation of antibiotics, providing an invaluable methodology for alleviation of aquatic environment pollution.