Sustainable Design of Molybdenum Disulfide Nanocomposites for Silver Recovery

Abstract

Recent increasing industrial demand for precious metals suggests recycling and regeneration as a means to decrease the energy consumption and cost associated with precious metal use. Molybdenum disulfide (MoS2) nanosheets have demonstrated selective and efficient adsorption potential toward heavy metals, but their application in recovering precious metals has not been reported. In this study, we affix MoS2 onto platforms to increase the sustainability and practicality of silver (used as a precious metal model) recovery from wastes, with the optimal design determined by effectiveness, sustainability, and scalability criteria. MoS2 was synthesized on three robust platformssand particles, alumina beads, and PTFE beadsusing bottom-up solvothermal methods. While a stable homogeneous molybdenum sulfides and oxides layer was formed over sand and alumina, PTFE beads were only partially coated. Silver was adsorbed onto MoS2@sand and MoS2@alumina at similar rates, but less was adsorbed on MoS2@PTFE. Recovery of silver from the nanocomposites was examined, and a thiourea and EDTA mixture was found to be the best desorbing solution, allowing over 80% silver recovery from MoS2@alumina. Our study indicates that among the platforms tested, alumina beads are the optimal MoS2 platform for precious metal recovery applications, allowing high adsorption and recovery rates with minimal Mo leaching. Overall, this study advances the utility and practical design of MoS2-based nanocomposites in water-treatment schemes, particularly for viable use in commercial aqueous metal recovery.

Interfacial Coordination Bonding-Assisted Redox Mechanism-Driven Highly Selective Precious Metal Recovery on Covalent-Functionalized Ultrathin 1T-MoS2

“…This approach heavily relies on PM recovery materials’ electronic and interfacial structure. Metallic molybdenum disulfide (1T-MoS 2 ), with a unique layered-like structure and electronic properties, exhibits remarkable PM recovery efficiency and colossal application potential in this field. − The selectivity of all of the reported 1T-MoS 2 for PM recovery is unsatisfactory. , Researchers progressively came to the conclusion that developing 1T-MoS 2 with a PM affinity environment might improve the selectivity for PM reduction. With this regard, a few proof-of-concept examples have been documented in the literature by mixing 1T-MoS 2 with PM affinity materials like chitosan or carbon nanotubes. , The interfacial reaction dynamics and structure–activity relationship underlying the recovery process are ambiguous, hindering the further exploration of high efficiency and selective adsorbents .…”