A magnetic graphene nanocomposite for efficient removal of methylene blue from wastewater

Nanostructured materials have several advantages over their bulk counterparts that can be exploited for water treatment. A magnetic graphene nanocomposite (Fe3O4/G) abbreviated as (MG) was synthesized using a solvothermal method and fully characterized using high-resolution transmission electron microscope (HR-TEM), Xray diffraction (XRD), a vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR) spectroscopy and zeta-potential measurements. Adsorption experiments for methylene blue (MB) dye removal were performed under different conditions. Parameters such as the initial dye concentration, pH, adsorbate/adsorbent contact time, adsorbent dosage and temperature were investigated. The dye removal efficiency was measured using a spectrophotometer. The results revealed that the adsorption behavior follows a pseudo-second-order kinetic model, and equilibrium was achieved after 15 min. The equilibrium data were well fitted with the Langmuir and Freundlich isotherm models. The MG nanocomposite exhibits an excellent removal efficiency (100%) for MB dye, and the magnetic properties of the magnetite nanoparticles in the nanosorbent allow a fast, magnetic separation of the adsorbent from an aqueous solution.