Synthesis and characterization of Ag-loaded p-type TiO2 for adsorption and photocatalytic degradation of tetrabromobisphenol A

A p-type TiO 2 with Ti vacancies (D-TiO 2 ) was synthesized by a facile solvothermal treatment, and Ag/TiO 2 with different Ag loading amount was prepared through a photo-reduction deposition method. The samples were characterized through scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The adsorption and photocatalytic characteristics of tetrabromobisphenol A (TBBPA) on D-TiO 2 and Ag/TiO 2 were investigated. The adsorption of TBBPA on Ag/TiO 2 was significantly enhanced and was five times greater than that of pure TiO 2 . The increase in pH significantly inhibited the adsorption of TBBPA. The 2%-Ag/TiO 2 nearly completely degraded TBBPA in 10 min under UV–Vis light (λ > 360 nm), and the apparent reaction rate constant ( k app ) reached 0.63 min −1 . The significantly enhanced UV–Vis light catalytic properties of the Ag/TiO 2 in comparison with that of TiO 2 were attributed to the increased adsorption capacity and electron transfer ability of the Ag/TiO 2 . Free radical trap experiments results showed that holes and superoxide radicals play a major role in the catalytic degradation of TBBPA by Ag/TiO 2 . Moreover, the Ag/TiO 2 catalyst exhibits high stability during TBBPA degradation even after three cycles. Practitioner points Ti-defected TiO 2 and Ag/TiO 2 were synthesized using a solvothermal and photo-reduction deposition, respectively. Ag/TiO 2 exhibited outstanding adsorption and photocatalytic activity for TBBPA removal under UV–Vis light. Holes and superoxide radicals play a major role in the photocatalytic degradation of TBBPA.