Polyol route synthesis of a Fe3O4@CuS nanohybrid for fast preconcentration of gold ions

Abstract

A magnetic Fe₃O₄@CuS nanohybrid has been successfully prepared by a rapid polyol route. The synthetic procedure includes refluxing a mixture of Fe₃O₄, CuSO₄ and sodium thiosulfate in ethylene glycol at 150 °C for 90 min. The prepared composite has been characterized using XRD, VSM, FE – SEM and Raman techniques. Gold adsorption properties of the nanostructure were investigated using flame atomic absorption spectroscopy (FAAS). The results indicate that the adsorption process is very fast as equilibrium is obtained within one minute with a maximum capacity of 333 mg g⁻¹. The isotherm study and error analysis showed that the adsorption process followed the Freundlich model. The regeneration study was also performed and the adsorbed ions were eluted with 0.5 mol L⁻¹ of thiosulfate solution. The limit of detection (LOD) was calculated as three times the standard deviation of the blank signal (n = 6) and it was 0.92 μg L⁻¹. Moreover, the relative standard deviation in the determination of 100 μg L⁻¹ of gold ions was found to be 3.4%.