Ion-exchange synthesis of one-dimensional Cd2Ge2O6/CdS core–shell composites and their enhanced visible-light photocatalytic activity

Abstract

One-dimensional (1D) Cd2Ge2O6/CdS core–shell composites were successfully synthesized by a facile ion-exchange method at room temperature. The composition, structure and property of the 1D Cd2Ge2O6/CdS core–shell composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (UV–vis DRS). The photocatalytic activity of the 1D Cd2Ge2O6/CdS core–shell composites was evaluated on the degradation of acid red G solution. The results showed that the 1D Cd2Ge2O6/CdS core–shell composite with 12.7wt% CdS exhibited a higher photocatalytic activity than the pure CdS under visible light irradiation. Theoretical analyses and scavenger experiment results suggested that the enhanced photocatalytic activity of the 1D Cd2Ge2O6/CdS core–shell composite was mainly attributed to the synergic effect from the well-matched band potentials and 1D core–shell structure.