Synthesis of magnetic iron oxide/graphene oxide nanocomposites for removal of cadmium ions from water

Abstract

In this study, magnetic iron oxide/graphene oxide (Fe3O4/GO) nanocomposites were developed for removal of cadmium ions (Cd2+) from water, which could be effectively separated from the solution owing to its superparamagnetic property. The Fe3O4/GO nanocomposites were fabricated by co-precipitation method with different precursor ratios of 8:1, 4:1, 2:1, and 1:1. It was found that the suitable ratio of Fe3O4/GO for Cd2+ ions adsorption was 4:1 (FG2). The effects of contact time, pH, and metal initial concentration on the adsorption properties of FG2 for Cd2+ in water were investigated. The adsorption data of FG2 followed pseudo-second-order kinetic and Langmuir isotherm models with the maximum adsorption capacity of 52.083 mg g−1 at pH 8. The structure and morphology of FG2 were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) specific surface area, and vibrating sample magnetometry (VSM). TEM images of FG2 presented the Fe3O4 nanoparticles in the size range of 10–15 nm decorated on GO nanosheets. The BET specific surface area of FG2 was observed to be 180.84 m2 g−1. VSM result of FG2 was 41.13 emu g−1. Accordingly, FG2 could be considered as a highly efficient adsorbent for removing Cd2+ from water.