Crystal surfaces cooperate with F ion migration to improve the photocatalytic performance of Z-type Ag-Ag2S/F-TiO2 composites

The TiO 2 has the problems of low utilization of visible light and high photogenerated carrier recombination rate. The photocatalytic activity of TiO 2 can be significantly improved by introducing F ion and narrow band gap material Ag 2 S. When F ions are present on the {001} surface of TiO 2 , surface F ions drive positively charged holes across the {001} surface, creating a synergistic effect that promotes the separation of electron-hole pairs. During the sample composite process, a certain amount of Ag will be precipitated to form an all-solid Z-type heterojunction structure of Ag 2 S, Ag and F-TiO 2 , which can improve the electron-hole separation efficiency. The results of XPS characterization confirmed the migration of F ion and the precipitation of Ag. The Ag 2 S/F-TiO 2 composite sample was referred to as AT for short, and the corresponding ratio was 1:10,1:20,1:30,1:40, the optimal sample AT 1:20 degraded 95.6% tetracycline hydrochloride within 2 hours. This work simultaneously realizes TiO 2 self-modification (synergistic effect of F ion migration and TiO 2 {001} crystal surface) and composite modification (formation of all-solid Z-type heterojunction), a new idea of studying TiO 2 self-modified cooperative heterostructures is proposed, and the good application potential of AT nanocomposites in photocatalytic water treatment technology is demonstrated.