Magnetic composite Fe3O4/CeO2 for adsorption of azo dye

In this paper, magnetic composite Fe3O4/CeO2 (MC Fe/Ce) was synthesized via CeO2 covered onto the surface of Fe3O4 by sol-precipitation method. The as-synthesized samples were characterized by FE-SEM, XRD, SEM-EDS and FT-IR spectrum. The pseudo-second-order (PSO) kinetic can describe well the adsorption of Acid black 210 (AB210) onto the as-obtained MC Fe/Ce of which the adsorption isotherm fits the Langmuir adsorption model better than Freundlich adsorption model. Furthermore, the maximum monolayer adsorption capacity of MC Fe/Ce is about 93 mg/g, which is 6 times more than that of commercial CeO2 for AB210. Moreover, the removal rate of the adsorbates for AB210 is 82.3% after first adsorption and still about 70% the fourth forth adsorption experiments within 120 min, which demonstrates that the obtained MC Fe/Ce has outstanding adsorption capacity and good stability. Additionally, the composite can be easily separated from aqueous solution in a few seconds with an external magnetic field due to its magnetic property, which is vital and has potential for its practical applications. (C) 2018 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.