Graphene oxide-mesoporous iron oxide nanohybrid: an efficient reusable nanoadsorbent for the removal of organic dyes from wastewater

We report a simple one-pot solvothermal synthesis of a magnetic nanoadsorbent composed of graphene oxide (GO) and mesoporous magnetite (m-Fe3O4) nanoparticles for the efficient removal of organic dyes from wastewater. As-synthesized GO/m-Fe3O4 hybrid which combines the excellent adsorption ability of GO and the magnetic separation advantage of m-Fe3O4 nanoparticles exhibited good adsorption capability toward rhodamine B (RhB) and methylene blue (MB) dyes in aqueous solutions. At an adsorbent dose of 1 mg ml−1, nearly 100% of RhB and 82% of MB having a concentration of 10 mg l−1 have been removed by the GO/m-Fe3O4 hybrid within only 5 min. The kinetics studies reveal that the adsorption of RhB and MB on GO/m-Fe3O4 hybrid follow the pseudo-second-order kinetic model. Furthermore, the GO/m-Fe3O4 hybrid exhibited good recyclable property; the removal rates being 100% and 64% respectively for RhB and MB even after ten successive adsorption/desorption cycles. The fast adsorption kinetics, easy magnetic extraction and renewal, together with good stability and removal efficiency even after sustained recycling make GO/m-Fe3O4 hybrid a cost-effective and promising adsorbent for the removal of organic dyes in wastewater treatment.