Preparation of magnetic core–shell iron oxide@silica@nickel-ethylene glycol microspheres for highly efficient sorption of uranium(vi)

Abstract

We report a facile approach for the formation of magnetic core–shell iron oxide@silica@nickel-ethylene glycol (Fe₃O₄@SiO₂@Ni-L) microspheres. The structure and morphology of Fe₃O₄@SiO₂@Ni-L are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen sorption isotherm. The composite possesses a high specific surface area of 382 m² g⁻¹. The obtained core/shell structure is composed of a superparamagnetic core with a strong response to external fields, which are recovered readily from aqueous solutions by magnetic separation. When used as the adsorbent for uranium(VI) in water, the as-prepared Fe₃O₄@SiO₂@Ni-L multi-structural microspheres exhibit a high adsorption capacity, which is mainly attributed to the large specific surface area and typical mesoporous characteristics of Fe₃O₄@SiO₂@Ni-L microspheres. This work provides a promising approach for the design and synthesis of multifunctional microspheres, which can be used for water treatment, as well as having other potential applications in a variety of biomedical fields including drug delivery and biosensors.