Synthesis of Fe3O4/graphene oxide nanocomposite for the treatment of heavy metals in the contaminated wastewater

Abstract

In this research, Fe₃O₄/graphene oxide nanocomposite was synthesized as an adsorbent for removal of Pb²⁺ from contaminated wastewater. According to this route, graphene oxide (GO) was synthesized from graphite via a modified Hummers method and for the preparation of Fe₃O₄/GO nanocomposite by impregnation. The result of XRD analysis showed that Fe₃O₄/GO nanocomposite has characteristic diffraction peaks corresponding to Fe₃O₄ and GO. Analysis of FTIR spectra indicated that the specific functional groups of Fe₃O₄ and GO in the nanocomposite. SEM and TEM images presented Fe₃O₄ nanoparticles in the average size of 10 nm are distributed on the surface of GO sheets. The BET specific surface area of the nanocomposite is about 72.9 m²/g. The TGA analysis demonstrated the thermal property of Fe₃O₄/GO nanocomposite. This material showed excellent magnetic behavior and therefore after adsorbing it can be recovered by applying an external magnetic field. The adsorption capacity of this nanocomposite was investigated and the concentration of residual Pb²⁺ ions in the solution was measured using ICP-OES. Equilibrium adsorption data were fitted by Langmuir isotherm model and the predicted maximum adsorption capacity was 54.64 mg/g.