Convenient fabrication of carbon doped WO3−x ultrathin nanosheets for photocatalytic aerobic oxidation of amines

Abstract It is an important chemical transformation for oxidation of amines to imines, on account of very important versatile applications of imines in organic synthesis. Here, we develop a convenient way to synthesize carbon doped WO 3−x ultrathin nanosheets via an acid-assisted one-pot process. The carbon doped WO 3−x ultrathin nanosheets exhibit excellent photocatalytic activity in the aerobic oxidation of amines to corresponding imines under visible light irradiation at room temperature. The high catalytic performance is attributed to remarkable visible light absorption ability and effective absorption of molecular oxygen and substrates. Rich oxygen-vacancies existing in the carbon doped WO 3-x ultrathin nanosheets may play an important role, because oxygen-vacancies not only change the band structure but also act as catalytic sites to activate molecular oxygen by photoproduct electrons to generate superoxide radicals. Both photoproduct holes and superoxide radicals play important role for the oxidation of amines.