Synergistic Effect of Photocatalyst CdS and Thermalcatalyst Cr₂O₃-Al₂O₃ for Selective Oxidation of Aromatic Alcohols into Corresponding Aldehydes

Selective transformation of alcohols to corresponding aldehydes has a crucial significance under mild conditions in industrial manufacturing. Herein, a novel photothermal catalyst (Cr2O3-Al2O3)/CdS (CAO/CdS) was successfully synthesized by coupling two-dimensional Cr2O3-Al2O3 (CAO) nanosheets and one-dimensional CdS nanorods. The CAO/CdS was characterized in detail. The synergistic effect of thermal catalyst CAO and photocatalyst CdS on the transformation of aromatic alcohols into aldehydes was verified. The result exhibited that alcohols could be oxidized into corresponding aldehydes efficiently under visible light illumination due to photocatalysis of CdS and thermal catalysis of CAO. CAO can weaken the bonds of O–H and C–Hα of alcohol at low temperatures, and CdS can produce active substances (·O2– and h+) for oxidizing alcohols to aldehydes under visible light illumination. The benzaldehyde yield increased about three times. It is proposed that the work has significant theoretical and practical values in photocatalysis studies.