Preparation of magnetic porous NiFe2O4/SiO2 composite xerogels for potential application in adsorption of Ce(iv) ions from aqueous solution

In this work, a novel magnetic porous adsorbent was prepared via a sol-gel method for the removal of Ce( iv ) from aqueous solution. The NiFe 2 O 4 /SiO 2 composite xerogels were characterized using SEM, BET, FT-IR, XPS, TEM, VSM and XRD. In addition, the effects of initial concentration, amounts of adsorbents, contact time, solution pH and temperature on the adsorption of Ce( iv ) were investigated via batch adsorption studies. The results verify the formation of hierarchically porous structures with a specific surface area of 1085.3 m 2 g −1 . The adsorption capacity for Ce( iv ) at 25 °C is 114.56 mg g −1 (91.65%), the adsorption of Ce( iv ) onto the composite xerogels was better described by the pseudo-second-order kinetic model, and the data fit well with the Langmuir isotherm model. Thermodynamic parameters such as standard enthalpy (Δ H 0 ), standard entropy (Δ S 0 ) and standard free energy (Δ G 0 ) indicated that the adsorption of Ce( iv ) onto composite xerogels was spontaneous and endothermic within the temperature range of 278-338 K. Moreover, the adsorbents showed good performance and recycling ability and could be separated by applying a magnetic field. In this work, a novel magnetic porous adsorbent was prepared via a sol-gel method for the removal of Ce( iv ) from aqueous solution.