Bi2WO6-x nanosheets with tunable Bi quantum dots and oxygen vacancies for photocatalytic selective oxidation of alcohols

Herein, Bi2WO6-x nanosheets with tunable Bi quantum dots and oxygen vacancies have been synthesized by a facile hydrothermal treatment combining in-situ redox reaction route, which exhibited the highly enhanced activity for selective oxidation of aromatic alcohols to carbonyl compounds in aqueous medium under visible-light irradiation for the first time. Results revealed that the highly enhanced activity of this photocatalyst was mainly attributed to the synergetic effect of Bi quantum dots and oxygen vacancies, which resulted in the narrowed energy band gap by inducing the formation of defect state level below the conduction band, the enhanced light-harvesting ability and the improved separation efficiency of photocharges. Meanwhile, this photocatalyst also displayed excellent durability owing to the strong interaction between Bi quantum dots and robust Bi2WO6-x nanosheets against significant deactivation caused by either the leaching of Bi quantum dots or the structural collapse of Bi2WO6-x nanosheets, showing its good potential in practical applications.