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 (Kd) 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. The authors demonstrate that metallic 2D transition metal dichalcogenides preferentially adsorb Au3+ and selectively reduce it to metallic gold, enabling efficient gold recovery from practical e-waste.