In situ construction of oxygen-vacancy-rich Bi^(0)@Bi_(2)WO_(6)-x microspheres with enhanced visible light photocatalytic for NO removal

摘要

Surface oxygen vacancy defects and metal deposition on semiconductor photocatalysts play a critical role in photocatalytic reactions.In this work,oxygen-deficient Bi_(2)WO_(6)microspheres have been prepared by a facile ethylene glycol-assisted solvothermal method.Bi0 nanoparticles were reduced by in situ thermaltreatment on Bi_(2)WO_(6)microspheres to obtain Bi^(0)@Bi_(2)WO_(6)-x as well as maintaining the oxygen vacancies(OVs)under N_(2)atmosphere.Afterwards,photocatalytic NO oxidation removal activities of these photocatalysts were investigated under visible light irradiation and Bi^(0)@Bi_(2)WO_(6)-x shows the best NO removal activity than other samples.The photogenerated cha rge separation and trans fe r are promoted by Bi0 nanoparticles deposited on the surface of semiconductor catalysts.OVs defects promote the activation of reactants(H_(2)O and O_(2)),thereby enhancing the formation of the active substance.Moreover,both OVs defects and Bi0 metal have the characteristics of extending light absorption and enhancing the efficient utilization of solar energy.Besides,the photocatalytic NO oxidation mechanism of Bi^(0)@Bi_(2)WO_(6)-xwas investigated by in situ FTIR spectroscopy for reaction intermediates and final products.This work furnishes insight into the synthesis strategy and the underlying photocatalytic mecha nism of the surfacemodified Bi^(0)@Bi_(2)WO_(6)-x composite for pollutants removal.