Fe3O4-functionalized UiO-66 with facile magnetic recovery for high-capacity and rapid uranium removal from contaminated aqueous solutions

Abstract

Nuclear energy serves as a cornerstone for realizing “dual-carbon” targets, yet the purification of uranium-contaminated aqueous systems remains a major bottleneck hampering the sustainable advancement of the nuclear industry. In this work, a magnetic Fe₃O₄@UiO-66 composite was fabricated via a sequential solvothermal synthesis of UiO-66 followed by an in situ hydrothermal growth of Fe₃O₄. The batch adsorption experiment demonstrated that the adsorption process of U(VI) on the Fe₃O₄@UiO-66 composite rapidly reaches equilibrium within 20 min, and its saturated adsorption capacity (338.78 mg g⁻¹) is 12.6 times that of pure Fe₃O₄ (26.91 mg g⁻¹). The adsorption data were well described using monolayer chemisorption models, as supported by both isotherm and kinetic fittings. Furthermore, the adsorbent enables swift isolation from the aqueous solution with the aid of an external magnetic field post-adsorption. This novel Fe₃O₄@UiO-66 composite thus offers an effective strategy for radioactive uranium decontamination in water, combining high adsorption performance with facile magnetic recovery.