The synthesis of core-shell magnetic dendritic fibrous nano-silica for the fast and selective capture of U(VI)

With the rapid development of nuclear industry, a large amount of U(VI)-containing wastewater is inevitably generated and poses a serious threat to the environment. Hence, it is of great significance to remove U(VI) from aqueous solution. Herein, a novel magnetic absorbent (Fe 3 O 4 @DFNS-NH 2 ) with core–shell and fibrous structure for U(VI) capture was fabricated. The magnetic core can make the adsorbent separated conveniently from solution and the functional porous shell facilitates the fast capture of U(VI). Batch experiments were carried out to investigate the performance of the magnetic absorbent. The U(VI) adsorption onto Fe 3 O 4 @DFNS-NH 2 reached equilibrium within 60 min at pH 6 and the adsorption capacity reached 255.2 mg g −1 . The adsorption followed the pseudo-second order model and Langmuir isotherm model, indicating the nature of monolayer chemisorption. In addition, Fe 3 O 4 @DFNS-NH 2 exhibited good selectivity toward U(VI) in the presence of metal ions (K + , Cs + , Ca 2+ , Mg 2+ , Sr 2+ and Eu 3+ ). FT-IR and XPS analysis demonstrated that U(VI) was anchored onto Fe 3 O 4 @DFNS-NH 2 through the surface complexation with amino groups. These findings manifest that Fe 3 O 4 @DFNS-NH 2 shows great potential to remove U(VI) from nuclear wastewater.