Efficient adsorption of gold ions from aqueous systems with thioamide-group chelating nanofiber membranes

Abstract We report on the efficient adsorption of gold ions from aqueous systems with thioamide-group chelating nanofiber membranes. The obtained membranes were prepared by a combination of chemical modification and electrospinning process. It was found that the maximum adsorption capacities of the chelating nanofibers toward Au(III) ions were 15.86 mmol/g, 23.50 mmol/g and 34.60 mmol/g, when the temperature was 298, 323 and 348 K, respectively. The nanofibers display a high adsorption efficiency for Au(III) ions. The Langmuir adsorption isotherm was applied to describe the adsorption processes. Kinetics of the Au(III) ions adsorption was found to follow pseudo-second-order rate equation. Furthermore, the as-prepared thioamide-group chelating nanofiber membranes, as well as Au(III) ions adsorbed nanofiber membranes, were carefully examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). Based on the characterization results, a possible mechanism of Au(III) ions adsorption with the thioamide-group chelating nanofiber membranes was proposed. This study provides a promising nanofiber adsorbent with high and efficient adsorption property for heavy metal ions removal.