Bi2WO6: A highly chemoselective visible light photocatalyst toward aerobic oxidation of benzylic alcohols in water

Abstract

Photocatalytic selective organic transformation in water using visible light as the driving force represents an environmentally benign strategy for synthesis of fine chemicals under the framework of green chemistry. We herein report the photocatalytic aerobic oxidation of benzylic alcohols to corresponding aldehydes with high selectivity in water over a flower-like Bi₂WO₆ semiconductor using oxygen as an oxidant under visible light irradiation and mild conditions. A collection of joint techniques, in terms of electron spin resonance (ESR) spectra and controlled experiments using radicals scavengers, have been employed to explain the origin of the high selectivity for oxidation of benzylic alcohols achieved over the flower-like Bi₂WO₆ photocatalyst in an aqueous phase. The possible reaction mechanism for photocatalytic selective oxidation of alcohols over Bi₂WO₆ has also been discussed.