Selective photocatalytic oxidation of aromatic alcohols using B-g-C3N4/Bi2WO6 composites

Abstract

In this work, B-g-C3N4/Bi2WO6 composites were synthesized by simple hydrothermal reaction and calcination, and their morphology, composition and physicochemical properties were characterized. The results show that the composite can selectively oxidize aromatic alcohols to aromatic aldehydes under visible light. The conversion rate of benzyl alcohol can reach 98.9% and the selectivity can reach 99% in 4 h, which are 1.59 times and 5.03 times that of Bi2WO6 alone, respectively. Further photoelectric performance investigation revealed that the recombination of B-g-C3N4 with Bi2WO6 effectively enhanced the separation of photogenerated carriers of B-g-C3N4 and suppressed the generation of holes on Bi2WO6, thereby improving the photocatalytic activity and the selectivity of the catalytic reaction of p-benzyl alcohol. In addition, the electronic effect and steric hindrance effect of substituents on the benzene ring on the selective catalytic oxidation of aromatic alcohols were also explored. Our work also reveals that the bandgap structure of the composites and the efficient separation of photogenerated electron transport are key factors to improve the photocatalytic reactivity and selectivity of organic reactions.