Facile preparation of mixed-phase CdS and its enhanced photocatalytic selective oxidation of benzyl alcohol under visible light irradiation

Abstract

Selective oxidation is one green technique for routine organics synthesis and environmental remediation. However, the conversion ratio resulted from environment-friendly method employing traditional photocatalytic materials like CdS is relatively low as compared with homogeneous catalytic reaction. Herein, in this paper, a facile method is reported to prepare mixed-phase CdS nanocrystals at room temperature. The as-prepared CdS samples were characterized by X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra (DRS), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic oxidation of benzyl alcohol into benzaldehyde catalyzed by as-prepared CdS was carried out with high conversion of 68% generated within 60 min using O2 as a benign oxidant under ambient condition. The enhanced catalytic activity could be attributed to the mixed-phased crystal structure which facilitates the separation of photogenerated charge carriers.