Fe3O4 modified mesoporous carbon nanospheres: Magnetically separable adsorbent for hexavalent chromium

Hexavalent chromium [Cr(VI)] is one of the most toxic cations and harmful to human health and the environment. Adsorption is found to be an effective method for the removal of Cr(VI) from aqueous solution. Herein, we synthesize the iron-containing magnetic mesoporous carbon nanospheres (Fe-MCNs) by introducing Fe3O4 nanoparticles into the carbon framework for removal of Cr(VI) from aqueous solution. The Fe-MCNs combined with Fe3O4 nanoparticles and mesoporous carbon nanospheres (MCNs) show a cooperative adsorption performance for Cr(VI). The Fe-MCNs possess monodispersed spherical structure with the diameter of ∼110 nm, surface area of 547 m2 g−1, as well as exhibit a high adsorption capacity of 87 mg g−1 and good recyclability for removing Cr(VI) from aqueous solution. Furthermore, with Fe3O4 nanoparticles in MCNs, Fe-MCNs can be separated and recovered from the aqueous solution conveniently and rapidly by the external magnetic field.