Enhanced photocatalytic degradation performance of Bi2 WO6 via O3 modification

Abstract

Bi2 WO6 with enhanced photocatlytic degradation performance was successfully synthesized by a facile O3 etching method. The photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, and ultraviolet-visible diffuse reflectance spectra. Characterization results revealed that the O3 treated Bi2 WO6 photocatalyst has abundant of oxygen vacancies, which could effectively restrain recombination of photon-generated carriers, broaden light absorption region, serve as pho-tocatalytic reaction center. Moreover, the photocatalytic activities of the prepared photocatalysts were evaluated by the photocatalytic degradation of benzidine under a xenon lamp irradiation. The photocatalytic activity of treated Bi2 WO6 photocatalyst samples with O3 pose a greater improve-ment. Among that, the O3-Bi2 WO6-3-4 modifying with ozone flux of 3.0 L/min for 4 h photocatalytic degradation of benzidine wastewater reached ~76.0% in 180 min under the irradiation of xenon lamp light (λ = 420 nm), which is about ~2.1 times higher than that of pure Bi2 WO6. Moreover, the photocatalytic activities of the modified Bi2 WO6 via O3 exhibit without significantly decrease after four cycles, indicating that the photocatalyst has a favourable application prospect.