Visible Light Photocatalytic Activity of Ag2S/Ag Nanocomposite Precipitated from Silver Thiosulfate Complex through Ultraviolet Photolysis

The thiosulfate system for silver extraction has numerous characteristics such as high efficiency, low consumption, and environmental protection, and it has good application prospects. However, the high cost of metal recovery in thiosulfate systems limits its industrial application. A previous study indicated that Ag2S/Ag nanocomposite clouds were precipitated from silver thiosulfate complex (AgTS) through ultraviolet photolysis, whereas the semiconductor-metal nanopowders synthesized through the hydrothermal synthesis process are usually important composites that can be used in photocatalysis, broad-spectrum antibacterial, and other environmental fields. Therefore, this study aims to develop high-value utilization of AgTS hydrometallurgical systems based on the photocatalytic properties of nanocomposites, and proposes research on the visible-light photocatalytic activity of Ag2S/Ag photocatalytic systems precipitated from AgTS through ultraviolet photolysis. First, the morphology and optical properties of the Ag2S/Ag nanocomposite were investigated. Next, the visible light photocatalytic activity of the Ag2S/Ag nanocomposite was evaluated, and finally, the new high-value utilization research method of “ultraviolet absorption → ultraviolet photolysis → photocatalysis” was proposed. In this study, we demonstrate a novel method of high-value utilization of silver thiosulfate lixivium with a high photocatalytic efficiency of the Ag2S/Ag nanocomposite of up to 47.98% after three cycles.