2-Aminothiazole Functionalized Polystyrene for Selective Removal of Au(III) in Aqueous Solutions

A new chelating resin, polystyrene-2-aminothiazole (PS-AT), was synthesized via one-step reaction by grafting 2-aminothiazole in a chloromethylated polystyrene polymer. Its structure was characterized by elemental analysis and infrared spectroscopy. Batch experiments were applied to investigate the adsorption properties of PS-AT for Au(III) ions. The resin exhibits an excellent selectivity for Au(III) ions in the presence of Ni(II), Cu(II), Cd(II), and Co(11) ions. The maximum adsorption capacity obtained at 308 K was 733.8 mg/g. The adsorption kinetic and equilibrium data were well fitted to the pseudo-second-order model and the Langmuir isotherm model, respectively. Desorption of gold from the resin can be achieved using 60 mL of 2 mol/L HCl-10% thiourea solution with a desorption ratio of 93.8%. The XPS data, along with IR spectra, revealed that gold was adsorbed on the surface of PS-AT in the form of chloride, and nitrogen and sulfur were involved in the chelation of gold chloride.