Photocatalytic degradation and removal mechanism of ibuprofen via monoclinic BiVO4 under simulated solar light

Characterized as by X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectra techniques, BiVO 4 photocatalyst was hydrothermally synthesized. The photocatalytic degradation mechanisms of ibuprofen (IBP) were evaluated in aqueous media via BiVO 4 . Results demonstrated that the prepared photocatalyst corresponded to phase-pure monoclinic scheelite BiVO 4 . The synthesized BiVO 4 showed superior photocatalytic properties under the irradiation of visible-light. The photocatalytic degradation rate of IBP decreased with an increase in the initial IBP concentration. The degradation process followed first-order kinetics model. At an IBP concentration of 10 mg L −1 , while a BiVO 4 concentration of 5.0 g L −1 with pH value of 4.5, the rate of IBP degradation was obtained as 90% after 25 min. The photocatalytic degradation of IBP was primarily accomplished via the generation of superoxide radical ( O 2 • − ${\text{O}}_2^{•-}$ ) and hydroxyl radicals ( • OH). During the process of degradation, part of the • OH was converted from the O 2 • − ${\text{O}}_2^{•-}$ . The direct oxidation of holes (h + ) made a minimal contribution to the degradation of IBP.