Construction of MoS2 nano-heterojunction via ZnS doping for enhancing in-situ photocatalytic reduction of gold thiosulfate complex

Recovery of gold thiosulfate complex ([Au(S 2 O 3 ) 2 ] 3− ) from leaching solutions has been recognized as a tough task, which limited the industrial promotion of eco-friendly thiosulfate leaching technique. In this work, MoS 2 /ZnS nano-heterojunction as a catalyst was proposed for the recovery of [Au(S 2 O 3 ) 2 ] 3− from leaching solution. The results indicated that [Au(S 2 O 3 ) 2 ] 3− could not only be efficiently recovered, but also in-situ reduced into Au 0 when MoS 2 /ZnS nano-heterojunction being used in the leaching solution. Mo 0.45 Zn 0.10 S exhibited an extremely high reduction capacity (1120.56 mg/g), which was 4.52 and 1.72 times of ZnS and MoS 2 , respectively. The great improvement was resulted from the ZnS doping on MoS 2 , which brought stronger light absorption, higher transferred efficiency and lower recombination of photogenerated electron-hole pairs of MoS 2 . In addition, the Au 0 could completely desorpt from MoS 2 /ZnS nano-heterojunctions in Na 2 S solution in less than 4 min, leading MoS 2 /ZnS nano-heterojunction to have remarkable cycling performances. This work provided a new insight for enhancing the recovery and in-situ reduction of gold thiosulfate complex from leaching solutions.