An Efficient Uranium Adsorption Magnetic Platform Based on Amidoxime-Functionalized Flower-like Fe₃O₄@TiO₂ Core–Shell Microspheres

Abstract

Efficient removal of uranium (U) from aqueous solutions is crucial for ecological safety. Functionalized magnetic nanoparticles provide a promising strategy for radionuclide recovery and separation. However, designing and synthesizing magnetic adsorbents with high sorption capacity and selectivity, accompanied by excellent stability and reusability, remain a challenge. In this work, novel amidoximefunctionalized flower-like magnetic Fe 3 O 4 @TiO 2 core−shell microspheres are designed and synthesized to efficiently remove U(VI) from aqueous solutions and actual seawater. The magnetic Fe 3 O 4 core facilitates easy separation by an external magnetic field, and flower-like TiO 2 nanosheets provide abundant specific surface areas and functionalization sites. The grafted amidoxime (AO) groups could function as a claw for catching uranium. The maximum adsorption capacity on U(VI) of the designed nanospheres reaches 313.6 mg•g −1 at pH 6.0, and the adsorption efficiency is maintained at 97% after 10 cycles. In addition, the excellent selectivity of the magnetic recyclable AO-functioning Fe 3 O 4 @TiO 2 microspheres endows the potential of uranium extraction from seawater. The designed material provides an effective and applicable diagram for radioactive element elimination and enrichment.

Indole-functionalized cross-linked chitosan for effective uptake of uranium(vi) from aqueous solution

“…The IAA-CTSA exhibited the highest adsorption capacity comparable to most of these alternative adsorbents. 4,28,29,37,57,[61][62][63][64][65][66][67][68][69] Particularly, the maximum adsorp-tion capacity (847.5 mg g −1 ) was dramatically higher than these selected CTS-based adsorbents. 4,28,29,57,[61][62][63][64][65][66][67][68][69] These results revealed the exceptional capture ability of U(VI) on IAA-CTSA benefitting from the synergy of electrostatic interactions, complexation and cation-π interactions.…”

“…4,28,29,37,57,[61][62][63][64][65][66][67][68][69] Particularly, the maximum adsorp-tion capacity (847.5 mg g −1 ) was dramatically higher than these selected CTS-based adsorbents. 4,28,29,57,[61][62][63][64][65][66][67][68][69] These results revealed the exceptional capture ability of U(VI) on IAA-CTSA benefitting from the synergy of electrostatic interactions, complexation and cation-π interactions. Thus, IAA-CTSA is an applicable, environmentally friendly and costeffective candidate for extraction, pretreatment and recovery of U(VI) in aqueous solution.…”

Magnetic Adsorbents for Wastewater Treatment: Advancements in Their Synthesis Methods

“…Recently, silica, apart from serving as a protection layer or functionalization bridge, has also been used as a hard template for the crystallization of titanium oxide-based nanosheets. Zhao et al [ 126 ] synthesized amorphous TiO 2 on silica–Fe 3 O 4 , using the Stöber method. Then, the silica layer was removed by dissolution in a strong alkali solution, followed by recrystallization of the H 2 Ti 2 O 5 nanosheet, by redissolving TiO 2 in diluted hydrochloric acid.…”

Development of a Fibrous Adsorbent Prepared Via Green Vapor-Phase Grafting Polymerization for Uranium Extraction

“…Xu et al first reported a kind of groundbreaking 3D hierarchical porous AO adsorbents via multi-step grafting polymerization which achieved a high capacity of 11.50 mg·g –1 after trimestral successive adsorption in natural seawater . Recently, a novel functionalized magnetic Fe 3 O 4 @TiO 2 core-shell microspheres were designed by Zhao et al via classical solvent hydrothermal method exhibited the maximum uranium adsorption capacity of 313.6 mg·g –1 at pH 6.0 . For uranium extraction from high salinity seawater, an outstanding investigation has reported a photoelectric-assisted method by exploiting a kind of bifunctional nitride material.…”

“…19 Recently, a novel functionalized magnetic Fe 3 O 4 @TiO 2 core-shell microspheres were designed by Zhao et al via classical solvent hydrothermal method exhibited the maximum uranium adsorption capacity of 313.6 mg•g −1 at pH 6.0. 20 For uranium extraction from high salinity seawater, an outstanding investigation has reported a photoelectric-assisted method by exploiting a kind of bifunctional nitride material. The result indicated that the extraction capacity of the adsorbent could be significantly improved to reach 1556 mg• g −1 under light illumination.…”