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 Au0 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.