Assembly of CdS Nanoparticles on the Two-Dimensional Graphene Scaffold as Visible-Light-Driven Photocatalyst for Selective Organic Transformation under Ambient Conditions

A series of cadmium sulfide-graphene (CdS-GR) nanocomposites with different weight addition ratios of graphene (GR) have been synthesized via a facile one-step hydrothermal approach, during which the formation of CdS nanoparticles and the reduction of graphene oxide (GO) occur simultaneously. X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), field-emission scanning electron microscopy (FE-SEM), transmission scanning electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen adsorption-desorption, photoluminescence spectra (PL), and electron spin resonance spectra (ESR) are employed to determine the properties of the samples. It is found that the CdS nanoparticles evenly overspread on the graphene scaffold, and the properties of the samples, including morphology, pore structure, optical, and electronic nature, are able to be tuned by the addition of GR as compared with blank-CdS prepared in the absence of GR. The photocatalytic activities of the as-prepared CdS GR nanocomposites are evaluated by selective oxidation of a range of alcohols under mild conditions. To our best knowledge, it is the first time to use CdS GR nanocomposites as visible light photocatalyst for selective organic transformation. Our results demonstrate that the as-prepared CdS GR nanocomposites can serve as a promising visible-light-driven photocatalyst for selective oxidation of alcohols to corresponding aldehydes. The high photoactivity of CdS GR can be ascribed to the integrative effect of enhanced light absorption intensity, high electron conductivity of GR, and its significant influence on the morphology and structure of the samples. It is hoped that our current work could widen the application of CdS GR nanocomposites and open promising prospects for the utilization of GR-based semiconductor nanocomposites as visible light photocatalyst for selective organic transformations.