Pb(II) removal of Fe3O4@SiO2–NH2 core–shell nanomaterials prepared via a controllable sol–gel process
Pb(II) removal of Fe3O4@SiO2–NH2 core–shell nanomaterials prepared via a controllable sol–gel process
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DOI：
10.1016/j.cej.2012.11.043
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发表时间：
2013-01
影响因子：
15.1
通讯作者：
Jian-Ming Zhang;S. Zhai;Shi Li;Zuoyi Xiao;Yu Song;Qing-da An;Ge Tian
中科院分区：
文献类型：
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作者：
Jian-Ming Zhang;S. Zhai;Shi Li;Zuoyi Xiao;Yu Song;Qing-da An;Ge Tian
天然水体中重金属（特别是铅离子）的污染是一个令人关注的主要问题，因此对有效吸附剂去除有毒离子的需求日益增加。由于氨基的任务特异性，Fe3O4@SiO2 - nh2的核壳纳米结构作为高级吸附剂被广泛研究；然而，对Fe3O4@SiO2substances表面改性的研究大多是环境效率低的接枝方法。在此，我们证明了单分散球形Fe3O4@SiO2 - nh2纳米材料可以很容易地通过绿色溶胶-凝胶工艺将TEOS与APTMS共缩聚制备。在最佳条件下制备的Fe3O4@SiO2 - nh2磁性纳米颗粒（MNPs）具有均匀的核壳结构（直径约200nm），相对较高的氨基功能负载（约5.45wt%），易于外部磁铁回收，有效去除Pb(II) （qm=243.9mg/g, 25°C）。结果表明，温度越高，吸附效果越好。吸附平衡数据符合Langmuir模型，动力学数据符合拟二阶模型。热力学研究揭示了该系统的可行性和吸热性质。这些结果表明，溶胶-凝胶法制备的Fe3O4@SiO2 -NH2具有易于合成、回收和生态友好的特点，是一种有潜力的去除Pb（II）的吸附剂。
Contamination of natural water with heavy metals (especially lead ions) is a problem of major concern and thus great demand of effective adsorbents for removal of toxic ions is increasing. Due to the task-specific properties of amino groups, core–shell nanostructures of Fe3O4@SiO2–NH2have been extensively investigated as advanced adsorbents; however, most studies on surface modification of Fe3O4@SiO2substances were of environmentally inefficient grafting methods. Herein, we demonstrated that mono-dispersed and spherical Fe3O4@SiO2–NH2nanomaterials can be facilely prepared by co-condensation of TEOS with APTMS employing a green sol–gel process. The as-prepared Fe3O4@SiO2–NH2magnetic nanoparticles (MNPs) prepared under optimum conditions possessing uniform core–shell structure (∼200nm in diameter), relatively high loading of amino-functionality (∼5.45wt%), easy recovery by external magnet and effective removal of Pb(II) (qm=243.9mg/g, 25°C). The adsorption was shown to be effective and a higher temperature was more favorable for the adsorption. The adsorption equilibrium data obeyed the Langmuir model and the kinetic data were well fitted to the pseudo-second-order model. Thermodynamic studies revealed the feasibility and endothermic nature of the system. These results demonstrated that the sol–gel produced Fe3O4@SiO2–NH2, due to its easy synthesis and recovery and eco-friendliness, can be a potential adsorbent for Pb(II) removal.