Preparation of nanocomposite Fe3O4@SiO2-PA for effective removal of Sb(III) from aqueous solutions: Kinetics, equilibrium and thermodynamic evaluation

Silica-coated magnetite (Fe3O4@SiO2) was functionalized with polyamide through a simple interfacial polymerization approach to synthesize a magnetic nanocomposite utilized for Sb(III) separation from aqueous solutions. The physical and chemical properties of Fe3O4@SiO2-polyamide (Fe3O4@SiO2-PA) nanocomposites were comprehensively studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), Magnetic property, and Brunauer-Emmett-Teller (BET) analysis methods. It was revealed by characterizations that polyamide polymer was uniformly grafted onto Fe3O4@SiO2 nanocomposites. The as-synthesized Fe3O4@SiO2-PA nanocomposites could be easily recovered from aqueous solutions by magnetic separation in 60 s. The adsorption data of Sb(III) were well fitted by Langmuir isotherm equation, and the maximum adsorption capacity for Sb(III) is 193.5 mg/g. The kinetics of adsorption data were well fitted by using the pseudo-second-order model, with the determination coefficients of 0.996 at 20 degrees C. The negative of change exothermic enthalpy Delta H (-70.4 kJ center dot mol-1) and Gibbs free energy Delta G (-175.1 kJ center dot mol-1) rendered the possibility of adsorption activity under given temperature parameters. By taking into account satisfactory adsorption efficiency it was concluded that the remediation of water pollution from Sb(III) could be achieved with such a great promising strategy.