Although mesoporous silica with magnetically hybridized two-dimensional channel structures has been well studied in recent years,it remains a challenge to fabricate the counterpart with macroporous three-dimensional c...Although mesoporous silica with magnetically hybridized two-dimensional channel structures has been well studied in recent years,it remains a challenge to fabricate the counterpart with macroporous three-dimensional cubic structures since the highly acidic preparation conditions lead to dissolution of magnetic particles.Herein,we successfully prepared magnetic KIT-6 nano-composite and its amino derivatives by bearing acid-resistant iron oxide.The prepared materials exhibited excellent properties for U(VI)ions removal from aqueous solutions under various conditions.The experimental data show that the U(VI)adsorption features fast adsorption kinetics,high adsorption capacity and ideal selectivity toward U(VI).The adsorption process is of spontaneous and endothermic nature and ionic strength independence,and the adsorbents can be easily regenerated by acid treatment.Compared to pristine KIT-6,the introduction of magnetism does not reduce the efficiency of the material to remove U(VI)while exerting its role as a recovery adsorbent.The findings of this work further demonstrate the potential broad application prospects of magnetic hybrid mesoporous silica in radionuclide chelation.展开更多
Functionalized magnetic Fe_3O_4@SiO_2 composite nanoparticles were prepared by simply embedding iron oxide nanoparticles into MCM-41 through one-step synthesis process, followed by aminopropyls grafting on the mesopor...Functionalized magnetic Fe_3O_4@SiO_2 composite nanoparticles were prepared by simply embedding iron oxide nanoparticles into MCM-41 through one-step synthesis process, followed by aminopropyls grafting on the mesopore channels, aiming to efficiently and conveniently uptake U(VI) from aqueous solution. The resultant material possesses highly ordered mesoporous structure with large surface area, uniform pore size, excellent thermal stability, quick magnetic response, and desirable acids resistance, confirmed by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), N_2 adsorption/desorption experiments, powder X-ray diffraction(PXRD), and thermogravimetric analysis(TGA). Detailed U(VI) sorption test indicated that this material is indeed an effective U(VI) sorbent with fast sorption kinetics of less than 2 h, large sorption capacity of 160 mg/g at p H 5.0±0.1, and desirable selectivity towards U(VI) ions over a range of competing metal ions. The absorbed U(VI) can be easily desorbed by 0.01 mol/L or more concentrated HNO_3 solution, and the reclaimed sorbent can be reused with no obvious decrease of sorption capacity even after 4 sorption-desorption cycles. The present results suggest the vast opportunities of this kind of magnetic composite on the solid-phase extraction of U(VI).展开更多
Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus re...Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus reagent extraction from aqueous komplexes （TALSPEAK） process, the organophosphorus ligand HDEHP （di-（2-ethylhexyl） phosphoric acid） has been used as an efficient reagent for the partitioning of Ln（Ⅲ） from An（Ⅲ） with the combination of a holdback reagent in aqueous lactate buffer solu- tion. In this work, the structural and electronic properties of Eu3＋ and Am3＋ complexes with HDEHP in nitric acid solution have been systematically explored by using scalar-relativistic density functional theory （DFT）. It was found that HDEHP can coordinate with M（Ⅲ） （M=Eu, Am） cations in the form of hydrogen-bonded dimers HL2 （L=DEHP）, and the metal ions pre- fer to coordinate with the phosphoryl oxygen atom of the ligand. For all the extraction complexes, the metal-ligand bonds are mainly ionic in nature. Although Eu（Ⅲ） complexes have higher interaction energies, the HL2- dimer shows comparable affini- ty for Eu（Ⅲ） and Am（Ⅲ） according to thermodynamic analysis, nonahydrate. It is expected that this work could provide insightful HDEHP at the molecular level. which may be attributed to the higher stabilities of Eu（Ⅲ） information on the complexation of An（Ⅲ） and Ln（Ⅲ） with展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22276193,U20B2019,and U2067212)the National Science Fund for Distinguished Young Scholars(Grant No.21925603).
文摘Although mesoporous silica with magnetically hybridized two-dimensional channel structures has been well studied in recent years,it remains a challenge to fabricate the counterpart with macroporous three-dimensional cubic structures since the highly acidic preparation conditions lead to dissolution of magnetic particles.Herein,we successfully prepared magnetic KIT-6 nano-composite and its amino derivatives by bearing acid-resistant iron oxide.The prepared materials exhibited excellent properties for U(VI)ions removal from aqueous solutions under various conditions.The experimental data show that the U(VI)adsorption features fast adsorption kinetics,high adsorption capacity and ideal selectivity toward U(VI).The adsorption process is of spontaneous and endothermic nature and ionic strength independence,and the adsorbents can be easily regenerated by acid treatment.Compared to pristine KIT-6,the introduction of magnetism does not reduce the efficiency of the material to remove U(VI)while exerting its role as a recovery adsorbent.The findings of this work further demonstrate the potential broad application prospects of magnetic hybrid mesoporous silica in radionuclide chelation.
基金supported by the National Natural Science Foundation of China (11275219, 11275090, U1432103)the “Strategic Priority Research program” of the Chinese Academy of Sciences (XDA030104)+1 种基金the State Key Laboratory of NBC Protection for Civilian (SKLNB201412)the Scientific Research Fund of Hunan Provincial Education Department (12A116)
文摘Functionalized magnetic Fe_3O_4@SiO_2 composite nanoparticles were prepared by simply embedding iron oxide nanoparticles into MCM-41 through one-step synthesis process, followed by aminopropyls grafting on the mesopore channels, aiming to efficiently and conveniently uptake U(VI) from aqueous solution. The resultant material possesses highly ordered mesoporous structure with large surface area, uniform pore size, excellent thermal stability, quick magnetic response, and desirable acids resistance, confirmed by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), N_2 adsorption/desorption experiments, powder X-ray diffraction(PXRD), and thermogravimetric analysis(TGA). Detailed U(VI) sorption test indicated that this material is indeed an effective U(VI) sorbent with fast sorption kinetics of less than 2 h, large sorption capacity of 160 mg/g at p H 5.0±0.1, and desirable selectivity towards U(VI) ions over a range of competing metal ions. The absorbed U(VI) can be easily desorbed by 0.01 mol/L or more concentrated HNO_3 solution, and the reclaimed sorbent can be reused with no obvious decrease of sorption capacity even after 4 sorption-desorption cycles. The present results suggest the vast opportunities of this kind of magnetic composite on the solid-phase extraction of U(VI).
基金the National Natural Science Foundation of China (21201166, 11275090)the Major Research Plan of Natural Science Foundation of China (91426302, 91326202)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA030104)the Natural Science Foundation of Hunan Province (12JJ9006)the Scientific Research Fund of Hunan Provincial Education Department (12A116)
文摘Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus reagent extraction from aqueous komplexes （TALSPEAK） process, the organophosphorus ligand HDEHP （di-（2-ethylhexyl） phosphoric acid） has been used as an efficient reagent for the partitioning of Ln（Ⅲ） from An（Ⅲ） with the combination of a holdback reagent in aqueous lactate buffer solu- tion. In this work, the structural and electronic properties of Eu3＋ and Am3＋ complexes with HDEHP in nitric acid solution have been systematically explored by using scalar-relativistic density functional theory （DFT）. It was found that HDEHP can coordinate with M（Ⅲ） （M=Eu, Am） cations in the form of hydrogen-bonded dimers HL2 （L=DEHP）, and the metal ions pre- fer to coordinate with the phosphoryl oxygen atom of the ligand. For all the extraction complexes, the metal-ligand bonds are mainly ionic in nature. Although Eu（Ⅲ） complexes have higher interaction energies, the HL2- dimer shows comparable affini- ty for Eu（Ⅲ） and Am（Ⅲ） according to thermodynamic analysis, nonahydrate. It is expected that this work could provide insightful HDEHP at the molecular level. which may be attributed to the higher stabilities of Eu（Ⅲ） information on the complexation of An（Ⅲ） and Ln（Ⅲ） with
