High efficiency gold extraction by 2D metallic 1T/1T' phase transition metal dichalcogenides

Recovery of precious metals from waste has high social and economic value, but in practice, recycling is often inefficient due to limits in technologies and materials. Here we show a group of materials-two-dimensional (2D) metallic 1 T/1 T' phase transition metal dichalcogenides (TMDs, MoS₂, WS₂, TaS₂, and TiS₂)-that allows for efficient, selective, and scalable extraction of valuable gold (Au) from leaching solutions of end-of-life electronics. The materials exhibit rapid kinetics, delivering an impressive 99.99% extraction efficiency of Au³⁺ in merely 0.25 min. Furthermore, they showcase strong selectivity for Au³⁺ adsorption, featuring a distribution coefficient (K_d) 5-6 orders of magnitude higher than that of other competitive cations (Cu²⁺, K⁺, Ni²⁺, Na⁺, Zn²⁺, Ca²⁺, and Mg²⁺). Amongst, TiS₂ exhibits an unprecedented extraction capacity of 9093 mg⋅g^-1 toward Au³⁺, which is approximately 1 order of magnitude higher than most other benchmark adsorbents (silver-organic frameworks). Importantly, through batch production of TiS₂ nanosheets (5 g) and subsequent membranes fabrication for gold extraction, we demonstrated 0.15 g gold (23.8 Karat) recovery by treating 30 discarded central processing units (CPUs). Our work provides a foundation for the efficient and selective recovery of high-value metals from waste, contributing to a sustainable and circular economy.