The amidoxime-functionalized magnetic dendritic fibrous nano-silica with a core–shell structure for the efficient capture of U(VI)

The U(VI) extraction from nuclear wastewater through adsorption techniques is vital for reclaiming uranium resources and mitigating environmental pollution. Herein, amidoxime-functionalized dendritic fibrous nano-silica with magnetic reponsiveness and core–shell structure (Fe 3 O 4 @DFNS-AO) was synthesized. The rapid absorption of U(VI) by Fe 3 O 4 @DFNS-AO achieved equilibrium within 40 min. Fe 3 O 4 @DFNS-AO showed great adsorption efficiency, as well as good reusability and selectivity, with a capacity of 175.4 mg/g at optimal pH 6.0. Furthermore, the mechanism was disclosed based upon the study of adsorption behavior and XPS analysis. The study of kinetic and isotherm indicated chemisorption dominated the adsorption and U(VI) could be adsorbed onto Fe 3 O 4 @DFNS-AO by monolayer. The amidoxime groups in Fe 3 O 4 @DFNS-AO acted as electron donors and formed coordination bonds with uranyl ions, leading to the efficient capture of U(VI). Overall, Fe 3 O 4 @DFNS-AO shows great promise in extracting uranium from wastewater.