In Situ Reduction of Au(I) for Efficient Recovery of Gold from Thiosulfate Solution by the 3D MoS2/Chitosan Aerogel

A three-dimensional porous MoS2/chitosan (MoS2/CS) aerogel with excellent mechanical strength and stability was constructed in this work through anchoring MoS2 to the surface of the CS aerogel. It is found that the MoS2/CS aerogel can effectively recover gold from thiosulfate solution via direct in situ reduction of Au(I) to Au-0 under sunlight, thus realizing the one-step recovery of gold, which greatly benefits the development of thiosulfate leaching for gold extraction. Furthermore, according to the results of photocurrent, ultraviolet-visible absorption, and atomic absorption spectrophotometry, it has been found that the reduction of the MoS2/CS aerogel to Au(I) is mainly consisted of photoreduction and chemical reduction, where photoreduction plays a dominant role, primarily because of the narrow band gap and higher conduction band edge of the MoS2/CS aerogel as well as the strong reducibility of photogenerated electrons.