Adsorption Performance of Co(Ⅱ) with Magnetic MOFs Fe₃O₄@SiO₂@UiO-66-SO₃H

The magnetic metal-organic framework (MOFs) Fe₃O₄@SiO₂@UiO-66-SO₃H was successfully prepared by hydrothermal method, and the structure, morphology and properties of the material were characterized by FT-IR, XRD, BET, VSM and XPS. In addition, the effects of pH value, time, temperature and initial concentration of Co(Ⅱ) on the adsorption performance of the material were also investigated. The results show that the maximum adsorption capacity of magnetic MOFs for Co(Ⅱ) is 106 mg/g at pH=8.3 and temperature of 298 K. At the same time, the kinetics and isotherm data of the adsorption process are fitted. The data show that the adsorption process is in accordance with the pseudo-second-order kinetics model and Langmuir isothermal model, and the adsorption is a spontaneous and endothermic process. Fe₃O₄@SiO₂@UiO-66-SO₃H is easy to be separated from the aqueous solution under the external magnetic field, and still has high adsorption performance after 5 cycles.