Syntheses and characterization of polystyrene-supported 2,5-dimercapto-1,3,4-thiodiazole and its sorption behavior for Pd(II), Pt(IV), and Au(III)

A type of chelating resin crosslinking polystyrene-supported 2,5-dimercapto-1,3,4-thiodiazole (also called bismuththiol I, BMT), containing sulfur and nitrogen atoms, was prepared. The structure of PS-BMT was confirmed by FTIR, elemental analysis, and X-ray photoelectron spectroscopy (XPS). Adsorption of Pd(II), Pt(IV), and Au(III) was investigated. The capacity of PS-BMT to adsorb Pd(II) and Pt(IV) was 0.190 and 0.033 mmol/g, respectively. The adsorption dynamics of Pd(II) showed that adsorption was controlled by liquid film diffusion and that the apparent activation energy, E-a, was 32.67 kJ/mol. The Langmuir model was better than the Freundlich model in describing the isothermal process of Pd(II), and the Delta G, Delta H, and Delta S values calculated were -0.33 kJ/mol, 26.29 kJ/mol, and 87.95 J mol(-1) K-1, respectively. The mechanisms of adsorption of Pd(II), Pt(IV), and Au(III) were confirmed by XPS. (c) 2006 Wiley Periodicals, Inc.