Highly efficient and selective recovery of Au(III) from a complex system by molybdenum disulfide nanoflakes

The design and synthesis of efficient adsorbing materials for recovery of precious metal are of paramount importance for fulfilling high-tech industry's need. Herein, a one-step hydrothermal synthesis method was employed to construct the sulfur-rich MoS2 nanoflakes under a mild condition. The first experiment evidence proved that MoS2 nanoflakes were capable of capturing gold, with an extremely high uptake capacity (1133 mg g(-1)) and excellent selectivity. More importantly, MoS2 nanoflakes showed preferential Au3+ uptake behaviour compared with other precious metal ions such as Pd2+ (47.6 mg g(-1)) and Pt4+ (38.5 mg g(-1)). Different factors affecting the sorption process such as pH, adsorbent amount, contact time, ion strength, and reusability were systematically studied. The adsorption mechanism may be attributed to their intrinsically sulfur-rich characteristic for the strong soft-soft interactions between S atoms and Au atoms. These findings open up the possibility to expand the applications of sulfur-rich nanomaterials in the recovery of precious metal.