Synthesis and characterization of robust Ag2S/Ag2WO4 composite microrods with enhanced photocatalytic performance

A series of Ag₂S/Ag₂WO₄ composite microrods with different Ag₂S contents (10-50 wt%) were synthesized via a facile successive precipitation route. The texture and optical properties of the pure Ag₂S, Ag₂WO₄, and Ag₂S/Ag₂WO₄ composites were intensively characterized by some physicochemical characterizations like N₂ physical adsorption, x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-visible spectroscopy, x-ray photoelectron spectroscopy, photoluminescence spectroscopy, and photocurrent measurements. Under visible light irradiation, different organic dyes, e.g., methylene blue and methyl orange dye were applied to evaluate the photocatalytic performances by their photocatalytic degradation reactions. The Ag₂S/Ag₂WO₄ composite microrods exhibited superior photocatalytic activity and stability. The high crystallinity of Ag₂WO₄ and improved texture properties of Ag₂S/Ag₂WO₄ resulted in their enhanced photocatalytic property. More importantly, the Ag₂S/Ag₂WO₄ heterojunctions with matching electronic band structures obviously enhanced the separation of photo-generated electrons and holes, further promoting the photocatalytic reaction.