Preparation of Y–TiO2@MIL-53(Fe) and performance study of photocatalytic degradation of tetracycline

Y–TiO2@MIL-53(Fe) photocatalyst composites were synthesized by a facile solvothermal method and their photocatalytic activity were assessed by photodegradation of tetracycline (TC) under visible light irradiation. Comprehensive material characterization, including XRD, XPS, BET, UV–Vis, SEM, and PL techniques, were employed to analyze the properties of the composites. Experimental results revealed that the removal rates of TC from a 20 mg/L TC solution using Y–TiO2, MIL-53(Fe), and Y–TiO2@MIL-53(Fe) were 61.0%, 75.1%, and 93.2% respectively, under specific conditions of 500 W UV-Hg lamp irradiation, a 30 min dark reaction, a 60 min light reaction, a Ti:Fe molar ratio of 1:1, and a catalyst concentration of 0.6 g/L. The Y–TiO2 component in Y–TiO2@MIL-53(Fe) primarily existed in the form of anatase, while Fe3+ ions entered the lattice gap or replaced Ti4+ ions at certain lattice positions, effectively inhibiting the recombination of photoelectrons and holes and broadening the light absorption band. This modification positively influenced the photocatalytic ability of the composites. Quenching experiments and ESR characterization confirmed that •O2−, •OH, and h+ were the active species involved in the photocatalytic process, with •O2− being the main active species. This investigation of the photocatalytic properties of the composites provides valuable insights into the photocatalytic reaction mechanism, supporting the application and further development of photocatalytic technology.