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摘要中空核壳纳米粒子(YSNs) 具有一种新型的核@空腔@壳的特殊核壳结构。论文采用两步包裹方法制备了四氧化三铁@水合氧化锆（Fe3O4@ZrO2•nH2O）中空核壳纳米粒子，并考察了其对吸附氟离子的性能。通过刻蚀Fe3O4@SiO2@ ZrO2•nH2O微球中的SiO2层，制备得到具有中空核壳结构的Fe3O4@ ZrO2•nH2O纳米粒子。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)和氮气吸附脱附仪等对Fe3O4@ ZrO2•nH2O的有序度、组成，外部形貌，内部结构，比表面积及孔径进行表征，并考察溶液的pH、竞争性阴离子和接触时间对材料吸附性能的影响。结果表明，Fe3O4@ ZrO2•nH2O纳米粒子具有磁性四氧化三铁内核、保护性外壳和中空空腔等结构特点，并且在酸性条件下具有良好的吸附氟离子的性能。吸附动力学研究表明，氟离子的吸附过程与伪二级动力学方程拟合最佳。吸附热力学研究表明，氟离子吸附等温线可由Langmuir方程描述。28867
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关键词 中空核壳纳米粒子 吸附 除氟
毕业论文设计说明书英文摘要
Title Enhanced Removal of Fluoride by Magnetic Fe3O4@ZrO2•nH2O spheres
Abstract
The yolk-shell particles (YSNs) represent a new class of special core-shell structures with a distinctive core@void@shell configuration. Here, we present an effective two-step strategy for fabricating of monodispersed yolk-shell Fe3O4@ZrO2•nH2O spheres (YHZOs) which demonstrate enhanced fluoride removal ability and acid-resist property. Specifically, the preformed monodispersed Fe3O4 spheres were used as templates for directing the sequential deposition of silica layer by modified Stöber method, subsequent ZrO2•nH2O layer via sol-gel route. The as-synthesized Fe3O4@ ZrO2•nH2O was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption/desorption. The influence of solution pH, competitive anions, and contact time was also examined. The results indicated that Fe3O4@ ZrO2•nH2O possess distinctive structures, including active cores, protective shells and hollow cavity. The YSNs， under acidic condition，show outstanding performance for adsorption of fluoride ions in drinking water. The adsorption kinetic results showed that the kinetic data of fluoride adsorption were fitted well by the pseudo-second-order kinetic model. And the adsorption isotherms can be fitted by Langmuir model well.
Keywords Yolk-shell particles adsorption removal of fluoride
目次
1 绪论 1
1.1 氟的性质 1
1.2 水体氟污染及除氟的必要性 1
1.3 水体中氟的来源 1
1.4 除氟的方法 2
1.4.1 混凝沉淀 2
1.4.2 膜处理工艺 2
1.4.3 离子交换法 3
1.4.4 吸附法 3
1.5 锆（IV）基吸附剂在氟吸附中的应用 3
1.6 吸附理论模型 4
1.6.1 吸附动力学模型 4
1.6.2 吸附等温式 5
1.7 Yolk-shell纳米颗粒的研究现状 5
1.8 Yolk-shell纳米颗粒的制备方法 6
1.8.1 选择性刻蚀 6
1.8.2 从内向外的软模板组装 6
1.8.3 瓶中造船 6
1.8.4 奥斯特瓦尔德熟化法 7