Alchemy-Inspired Green Paper for Spontaneous Recovery of Noble Metals.

Recycling of noble metal from waste materials, namely from electronic wastes (e-waste), spent catalyst, and industrial wastewater, is attracting growing attention due to the scarcity, economic importance, and criticality of those noble metals. Traditional techniques reported to date require toxic reagent and strict extraction conditions, which deeply hinders the development of precious metal recovery in complex environments. Here, an approach is proposed that uses flexible metallic transition metal dichalcogenide (TMD) paper, which provides abundant active sites for spontaneous adsorption and reduction of noble metal ions, as an Alchemy-inspired template to recover noble metal in an efficient and green way without the aid of reductant and heating. The metallic TMD (MoS2, WS2) paper is shown to rapidly extract five noble metal ions (Au, Pd, Pt, Ag, and Ru) from complex samples containing various interferents. This unique property endows the metallic TMD paper with gifted ability in extracting gold from e-waste, and recovering platinum group metals (palladium and platinum) from spent catalysts, which provides a blueprint for the design of next-generation green platforms for noble metal regeneration.