Preparation and Property of Oxygen-deficient Bi2WO6-x Photocatalyst Active in Visible Light

Oxygen-deficient Bi2WO6-x catalyst was prepared in situ by a solvothermal method using ethylene glycol as the solvent. The physicochemical properties of the as-prepared catalyst were characterized by XRD, SEM, N-2 isothermal, XPS, ESR, UV-Vis DRS, PL and electrochemical analyses. The photocatalytic activity of catalysts was evaluated by the degradation of gaseous benzene under visible-light irradiation (lambda > 400 nm). The results indicate that the oxygen-deficient Bi2WO6-x with a larger specific surface area possesses Bi-O-v and W-O-v oxygen vacancies. The formation of oxygen defects narrows optical bandgap of Bi2WO6 and hinders photoinduced electron-hole pairs from recombination, which enhances the photocatalytic activity. The conversion and mineralization rates of benzene on the as-prepared Bi2WO6-x are increased up to 52.5% and 80.6%, respectively, which are correspondingly 1.72 and 1.84 times as high as those on the pristine Bi2WO6.