Synthesis of magnetic iron oxide/graphene oxide nanocomposites for removal of cadmium ions from water Report presented at 9th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2018), 7-11 November 2018, Ninh Binh City, Vietnam

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.