Synthesis of amidoxime-functionalized Fe3O4@SiO2 core–shell magnetic microspheres for highly efficient sorption of U(VI)
Synthesis of amidoxime-functionalized Fe3O4@SiO2 core–shell magnetic microspheres for highly efficient sorption of U(VI)
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DOI：
10.1016/j.cej.2013.09.034
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发表时间：
2014
影响因子：
15.1
通讯作者：
Yingguo Zhao;Jiaxing Li;Lanping Zhao;Shouwei Zhang;Yongshun Huang;Xinlin Wu;Xiangke Wang
中科院分区：
文献类型：
--
作者：
Yingguo Zhao;Jiaxing Li;Lanping Zhao;Shouwei Zhang;Yongshun Huang;Xinlin Wu;Xiangke Wang
合成了酰胺肟功能化的SiO2包覆Fe 3 O 4（Fe3O4@SiO2-AO），并通过扫描电镜、透射电镜、X射线衍射、傅里叶变换红外光谱和磁性测量对其进行了表征。将制备的Fe3O4@SiO2-AO应用于吸附水中的U（VI），由于偕胺肟对U（VI）的强螯合作用，其对U（VI）的吸附能力比未改性SiO2包覆的Fe 3 O 4有明显的提高。研究了接触时间、pH、离子强度、干扰离子、U（VI）浓度和温度对Fe3O4@SiO2-AO吸附U（VI）的影响。Fe3O4@SiO2-AO吸附U（VI）的动力学过程在2 h内达到平衡。吸附强烈依赖于pH值和独立的离子强度，表明吸附主要是由内球表面络合。吸附等温线符合Langmuir模型，在pH = 5.0 ± 0.1和T = 298 K时，最大吸附量为0.441 mmol g− 1。负载U（VI）的Fe3O4@SiO2-AO可以通过外磁场从水溶液中容易地分离，并且可以用1 mol L−1HCl有效地再生，而U（VI）吸附能力仅略有下降。研究结果表明，Fe_3O_4@SiO_2-AO是一种很有潜力的分离富集海水和污染废水中U（VI）的新材料。
Amidoxime-functionalized silica coated Fe3O4(Fe3O4@SiO2-AO) was synthesized and carefully characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic measurements. The prepared Fe3O4@SiO2-AO was applied to adsorb U(VI) from aqueous solutions and exhibited enhanced sorption capacity for U(VI) in comparison with raw silica coated Fe3O4due to the strong chelation of amidoxime to U(VI). Effects of contact time, pH, ionic strength, interfering ions, U(VI) concentration, and temperature on the sorption of U(VI) on Fe3O4@SiO2-AO were investigated. The kinetic process of U(VI) sorption on Fe3O4@SiO2-AO reached equilibrium within 2 h. The sorption was strongly dependent on pH and independent of ionic strength, indicating that the sorption was mainly dominated by inner-sphere surface complexation. The sorption isotherm agreed well with the Langmuir model, having a maximum sorption capacity of 0.441 mmol g−1at pH = 5.0 ± 0.1 andT= 298 K. The U(VI)-loaded Fe3O4@SiO2-AO could be readily separated from aqueous solutions by an external magnetic field and efficiently regenerated by 1 mol L−1HCl with only slight decrease in U(VI) sorption capability. Findings of the present work suggest that Fe3O4@SiO2-AO is a potential and suitable candidate for the preconcentration and separation of U(VI) from seawater and contaminated wastewater.