Synergy of Oxygen Vacancies and Acid Sites on N-Doped WO3 Nanobelts for Efficient C–C Coupling Synthesis of Benzoin Isopropyl Ether

Abstract

The surface property of a photocatalyst, including surface acid sites and oxygen vacancies, plays a pivotal role in photocatalytic organic synthesis reactions. Benzoin isopropyl ether (BIE) is usually produced via polycondensation of benzaldehyde and catalyzed with highly toxic cyanide. Here, we report a green photocatalytic approach for the selective synthesis of BIE over WO3 driven by a green-light-emitting diode. The improved photocatalytic activity can be attributed to the synergy of oxygen vacancies (VOs) and acid sites over N-doped WO3 nanobelts. The results revealed that reactant molecules were predominantly adsorbed and activated on surface oxygen vacancies (VOSs) and the Brønsted acid promoted the etherification reaction; the introduction of VOs and nitrogen altered the band structure and electronic properties, resulting in improved photocatalytic activity. Our work provides an efficient approach to the selective photocatalytic synthesis of organics over photocatalysts with finely tuned surface properties and band structures via defect and doping engineering.