Selective oxidation of aromatic alcohols to aromatic aldehydes by BN/metal sulfide with enhanced photocatalytic activity

BN/metal sulfide composite (BN/In2S3) was prepared by a facile in situ one-pot hydrothermal method. The as-synthesized photocatalyst was characterized by X-ray powder diffraction (XRD), UV-vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N-2-sorption analysis, electron spin resonance (ESR), photoluminescence emission spectra (PL) and X-ray photoelectron spectroscopy (XPS). The results show that compared with single In2S3, the BN/In2S3 photocatalyst exhibits excellent photocatalytic performance for selective oxidation of aromatic alcohols to aromatic aldehydes under visible light irradiation. The enhanced photocatalytic activity of BN/In2S3 composite is mainly attributed to the unique physicochemical properties of BN nanosheet, which acts as a promoter for photoexcited holes transfer, thereby improving the charge separation efficiency and prolonging photoexcited electrons lifetime. Effects of the type of aromatic alcohol and the added scavenger on the photocatalytic efficiency were also investigated. O-center dot(2)- radicals and photogenerated holes play decisive roles for photocatalytic oxidation of aromatic alcohols to aromatic aldehydes. This approach is versatile for constructing other high efficiency photocatalysts such as BN/CdS, BN/Cd(x)Z(1-x)S and BN/ZnIn2S4. It is hoped that this work could provide new insights to construct the BN-based composites for extensive photocatalytic applications. (C) 2015 Elsevier B.V. All rights reserved.