The preparation, characterization of TiO2-X/Ag3PO4 heterojunctions with enhanced photocatalytic visible-light performance

A critical issue in the removal of fluoroquinolone antibiotics, which were frequently detected in drinking water sources and water treatment plants, is the design of highly efficient photocatalysts . In order to utilize visible-light, improve the electrons transfer and reduce the recombination of photogenerated carriers, TiO 2-X /Ag 3 PO 4 heterojunctions were fabricated by hydrothermal technology combined with the coprecipitation method for the first time. The morphological, structural, and optical properties of as-prepared catalysts were extensively characterized. In comparison with single-phase TiO 2-X and Ag 3 PO 4 , TiO 2-X /Ag 3 PO 4 composite exhibited enhanced photocatalytic efficiency for the degradation of methyl orange (MO) and gatifloxacin (GAT). Especially for the composite with the mole ratio of TiO 2-X and Ag 3 PO 4 was 1:1, the reduction of antimicrobial activity of the GAT byproducts reached 82.4% after 5 min visible-light irradiation. Furthermore, the pathway in photocatalytic decomposition of GAT was proposed by HPLC-MS and the electron transfer mechanism over TiO 2-X /Ag 3 PO 4 heterojunctions was suggested by the radical capture experiments, transient photocurrent responses, and electrochemical impedance spectroscopy tests.