Fabrication of Amino Functionalized Magnetic Expanded Graphite Nanohybrids for Application in Removal of Ag(I)‎ from Aqueous Solution

Abstract EN

Ethylenediamine functionalized magnetic expanded graphite decorated with Fe3O4 nanoparticles (MEG-NH2) was fabricated by one-pot solvothermal method.

The as-prepared MEG-NH2 nanohybrids were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Zeta potential analyzer.

The effects of Fe3O4 content in MEG-NH2 nanohybrids, pH, initial concentration, contact time, and dosage on adsorption properties of the MEG-NH2 nanohybrids for Ag(I) from aqueous solution were investigated by batch experiments.

The pseudo-first-order and the pseudo-second-order kinetic models were utilized to study adsorption kinetics.

The experimental data was also analyzed with Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models.

The results show that Ag(I) was reduced to silver in the process of the adsorption by MEG-NH2 nanohybrids; the experimental data was better fitted to pseudo-second-order model and Langmuir isotherm model which revealed that the adsorption process was a chemical adsorption by the formation of silver on the surface of MEG-NH2 nanohybrids.