Dual thiols-decorated metal–organic framework for efficient separation and recovery of gold

Abstract

The selective adsorption and recovery of gold (Au) from water is highly necessary due to its shortage and large value. Herein, we anchored meso-2,3-dimercaptosuccinic acid (DMSA) in metal–organic framework (MOF) to obtain a novel adsorbent, MOF-808-DMSA. Benefited from highly dispersed and dense thiol groups, MOF-808-DMSA exhibits a high adsorption capacity of 2008.4 mg g−1 with an equilibrium time of 60 min, superior to most of MOF-based adsorbents. Common metal cations and anions have negligible effects on the capture of Au(III) ion, and effective adsorption (>99.0%) is feasible under a wide acidic pH range of 1.0–6.0. Based on that, the selective capture of Au(III) ion from a real electronic wastewater was achieved successfully. Furthermore, via using hydrochloric acid-thiourea aqueous solution as the eluent, Au(III)-adsorbed adsorbent can be well regenerated. Combining density functional theory calculations and experimental analysis, the strong chemical affinity of Au(III) ion and the active groups with dispersed distribution was verified.