Synthesis, optical, photocatalytic, and electrochemical studies on Ag2S/ZnS and ZnS/Ag2S nanocomposites

摘要

Novel Ag₂S/ZnS and ZnS/Ag₂S nanocomposites were synthesized by a simple chemical method in air. Different morphologies were obtained for Ag₂S/ZnS nanocomposites annealed at different temperatures. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible absorption, and photoluminescence (PL) spectroscopy. Thermal stability and phase transition of the sample were studied by TG–DTA. Compared the PL spectra of Ag₂S/ZnS at 640?nm, it was significantly red shifted from 640 to 670?nm for reversed ZnS/Ag₂S nanocomposites. The band gaps of nanocomposites were lying between 2.25 and 2.55?eV range. It has been found that as-synthesized powder has excellent photocatalytic activity toward degradation of methylene blue (MB) under visible light and electrochemical activity, indicating that Ag₂S/ZnS and ZnS/Ag₂S nanocomposites can play an important role as semiconductor photocatalyst and energy storage applications.