Amidoxime modified Fe₃O₄@TiO₂ particles for antibacterial and efficient uranium extraction from seawater

Uranium extraction and recovery play a critical role in guaranteeing the sustainable nuclear energy supply and protecting the environmental safety. The ideal uranium sorbents possess high adsorption capacity, excellent selectivity and reusability, as well as outstanding antimicrobial property, which are greatly desired for the real application of uranium extraction from seawater. To address this challenge, a novel magnetic core-shell adsorbent was designed and fabricated by a facile method. The obtained amidoximed Fe₃O₄@TiO₂ particles (Fe₃O₄@TiO₂-AO) achieved equilibrium in 2 h and the maximum adsorption capacity calculated from Langmuir model is 217.0 mg/g. The adsorption kinetics followed the pseudo-second-order model. Meanwhile, the Fe₃O₄@TiO₂-AO exhibited great selectivity when competitive metal ions and anions coexisted. In addition, the magnetic Fe₃O₄@TiO₂-AO could be conveniently separated and collected by an external magnetic field, the regeneration efficiency maintained at 78.5% even after ten adsorption-desorption cycles. In natural seawater, the uranium uptake reached 87.5 μg/g in 33 days. Furthermore, the TiO₂ contained adsorbent showed effective photo induced bactericidal properties against both E. coli and S. aureus. The Fe₃O₄@TiO₂-AO with great U(VI) adsorption performance is highly promising in uranium extraction and reclamation.