Short channel platelet SBA-15 mesoporous material is one of the effective adsorbent for the recovery of U(Ⅵ) from aqueous solution. Nevertheless, the defect is that the mesoporous size limits the total stripping of a...Short channel platelet SBA-15 mesoporous material is one of the effective adsorbent for the recovery of U(Ⅵ) from aqueous solution. Nevertheless, the defect is that the mesoporous size limits the total stripping of attached U(Ⅵ) in recycling use and the increasing densities of organic groups after functionalization. Thus, a simple and controllable method was adopted to prepare SBA-15-type material with expanded pore channel by adding trimethylbenzene in synthesis procedure. The structure, morphology and functional groups were characterized by scanning electron microscope, powder X-ray diffraction, thermogravimetric analysis, transmission electron microscope, FTIR and N_2 adsorption-desorption isotherm analysis. Furthermore, the adsorption behavior of obtained product was test under various factors such as initial concentration, pH, elution rate and contact time. The pore expanded platelet SBA-15 exhibited higher U(Ⅵ) adsorption capacity, higher elution rate, and more bearing of amidoxime groups. Due to the higher amidoxime groups, the adsorption capacity of U(Ⅵ) on the amidoxime functionalized pore-expanded SBA-15 was 674 mg-Ug^-1. The results show that the simple and controllable pore-expanded method is an effective strategy to enhance the elution effect and increase grafting amount of organic groups on the mesoporous materials.展开更多
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
基金financially supported by the Fundamental Research Funds for the Central Universities (No. 201964020)the National Natural Science Foundation of China (No. U1607124)。
文摘Short channel platelet SBA-15 mesoporous material is one of the effective adsorbent for the recovery of U(Ⅵ) from aqueous solution. Nevertheless, the defect is that the mesoporous size limits the total stripping of attached U(Ⅵ) in recycling use and the increasing densities of organic groups after functionalization. Thus, a simple and controllable method was adopted to prepare SBA-15-type material with expanded pore channel by adding trimethylbenzene in synthesis procedure. The structure, morphology and functional groups were characterized by scanning electron microscope, powder X-ray diffraction, thermogravimetric analysis, transmission electron microscope, FTIR and N_2 adsorption-desorption isotherm analysis. Furthermore, the adsorption behavior of obtained product was test under various factors such as initial concentration, pH, elution rate and contact time. The pore expanded platelet SBA-15 exhibited higher U(Ⅵ) adsorption capacity, higher elution rate, and more bearing of amidoxime groups. Due to the higher amidoxime groups, the adsorption capacity of U(Ⅵ) on the amidoxime functionalized pore-expanded SBA-15 was 674 mg-Ug^-1. The results show that the simple and controllable pore-expanded method is an effective strategy to enhance the elution effect and increase grafting amount of organic groups on the mesoporous materials.
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.
