The extraction of uranium from seawater is challenging though it offers tremendous potential for the sustainable production of nuclear fuel for the energy sector.Herein,we report a new strategy for efficient extractio...The extraction of uranium from seawater is challenging though it offers tremendous potential for the sustainable production of nuclear fuel for the energy sector.Herein,we report a new strategy for efficient extraction of uranium from seawater via converging the cooperative functions of adsorption-photocatalysis into the nanospace of covalent organic frameworks(COFs).Functionalization of the organic linkers in the multicomponent COFs allowed exploration of the relationship between material composition and adsorption-photocatalytic activity for uranium extraction.The presence of amidoxime groups in the COFs offered selective binding sites for uranyl,whilst triazine units and bipyridine-Pd groups acted cooperatively to photocatalytically reduce adsorbed U(Ⅵ)to a U(Ⅳ)solid product(UO2)for facile collection.One of our developed COFs,4-Pd-AO,displayed exceptional performance in sequestering and reducing uranyl from natural seawater,with a high extraction capacity of 4.62 mg U/g per day(average data)under visible light irradiation.Mechanistic studies revealed that 4-Pd-AO not only reduced adsorbed uranyl(Ⅵ)to U(Ⅳ)O_(2),but also generated ^(1)O_(2) and superoxide radicals under visible light excitation,thus affording excellent antibacterial and antialgal activities(i.e.,antibiofouling properties)for sustained efficient uranium extraction performance.This proof-ofconcept study establishes multicomponent COFs as promising candidates for efficient uranium extraction from seawater.展开更多
Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditi...Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditional photocatalysts in carbonate-containing uranium wastewater.In this paper,theγ-FeOOH/konjac glucomannan grafted with phenolic hydroxyl groups/poly-N-isopropylacrylamide(γ-FeOOH/KGM(Ga)/PNIPAM)thermosensitive hydrogel is proposed as the photocatalysts for extracting uranium from carbonate-containing uranium wastewater.The dynamic phase transformation is demonstrated to confirm the arbitrary transition ofγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel from a dispersed state with a high specific surface area at low temperatures to a stable aggregated state at high temperatures.Notably,theγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel achieves a remarkably high rate of 92.3%in the removal of uranium from the wastewater containing carbonates and maintains the efficiency of uranium removal from uranium mine wastewater at over 90%.Relying on electron spin resonance and free radical capture experiment,we reveal the adsorption-reduction-nucleation-crystalliza tion mechanism of uranium onγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel.Overall,this strategy provides a promising solution to treating uranium-contaminated wastewater,showing a massive potential in water purification.展开更多
基金funding support from the National Science Foundation of China(grant nos.U2167218 and 22006036)National Key Research and Development Program of China(grant nos.2017YFA0207002 and 2018YFC1900105)+4 种基金the Science Challenge Project(grant no.TZ2016004)the Beijing Outstanding Young Scientist Programthe Students Innovation Training Program(grant no.202106014)the Robert A.Welch Foundation(B-0027)(S.M.)support from the 14W station in Shanghai Synchrotron Radiation Facility(SSRF).
文摘The extraction of uranium from seawater is challenging though it offers tremendous potential for the sustainable production of nuclear fuel for the energy sector.Herein,we report a new strategy for efficient extraction of uranium from seawater via converging the cooperative functions of adsorption-photocatalysis into the nanospace of covalent organic frameworks(COFs).Functionalization of the organic linkers in the multicomponent COFs allowed exploration of the relationship between material composition and adsorption-photocatalytic activity for uranium extraction.The presence of amidoxime groups in the COFs offered selective binding sites for uranyl,whilst triazine units and bipyridine-Pd groups acted cooperatively to photocatalytically reduce adsorbed U(Ⅵ)to a U(Ⅳ)solid product(UO2)for facile collection.One of our developed COFs,4-Pd-AO,displayed exceptional performance in sequestering and reducing uranyl from natural seawater,with a high extraction capacity of 4.62 mg U/g per day(average data)under visible light irradiation.Mechanistic studies revealed that 4-Pd-AO not only reduced adsorbed uranyl(Ⅵ)to U(Ⅳ)O_(2),but also generated ^(1)O_(2) and superoxide radicals under visible light excitation,thus affording excellent antibacterial and antialgal activities(i.e.,antibiofouling properties)for sustained efficient uranium extraction performance.This proof-ofconcept study establishes multicomponent COFs as promising candidates for efficient uranium extraction from seawater.
基金supported by the National Natural Science Foundation of China(21976147,U2267224,and 22106126)the Sichuan Science and Technology Program(2021YFG0096,2024NSFSC1148,2022YFG0371,and 2024NSFTD0012)+2 种基金the Project of State Key Laboratory of Environmentfriendly Energy Materials in Southwest University of Science and Technology(21fksy22)the Research Fund of Southwest University of Science and Technology for PhD(23zx7103)the Open Fund of China National Nuclear Corporation Key Laboratory for Uranium Extraction from Seawater(KLUES202201).
文摘Exploiting the intelligent photocatalysts capable of phase separation provides a promising solution to the removal of uranium,which is expected to solve the difficulty in separation and the poor selectivity of traditional photocatalysts in carbonate-containing uranium wastewater.In this paper,theγ-FeOOH/konjac glucomannan grafted with phenolic hydroxyl groups/poly-N-isopropylacrylamide(γ-FeOOH/KGM(Ga)/PNIPAM)thermosensitive hydrogel is proposed as the photocatalysts for extracting uranium from carbonate-containing uranium wastewater.The dynamic phase transformation is demonstrated to confirm the arbitrary transition ofγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel from a dispersed state with a high specific surface area at low temperatures to a stable aggregated state at high temperatures.Notably,theγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel achieves a remarkably high rate of 92.3%in the removal of uranium from the wastewater containing carbonates and maintains the efficiency of uranium removal from uranium mine wastewater at over 90%.Relying on electron spin resonance and free radical capture experiment,we reveal the adsorption-reduction-nucleation-crystalliza tion mechanism of uranium onγ-FeOOH/KGM(Ga)/PNIPAM thermosensitive hydrogel.Overall,this strategy provides a promising solution to treating uranium-contaminated wastewater,showing a massive potential in water purification.
