氧化铁纳微结构材料的合成及应用研究
文献类型：学位论文
| 作者 | 李军 |
| 学位类别 | 博士 |
| 答辩日期 | 2010-05-28 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 王丹 |
| 关键词 | 多级结构 空心球 多壳层结构 金属氧化物 Cr(VI)吸附 |
| 其他题名 | Study on Synthesis and Property of Iron Oxide Nano/Microstructures |
| 学位专业 | 化学工程 |
| 中文摘要 | 氧化铁是一种典型的环境友好材料，被广泛的应用在涂料、传感器、催化、电极、磁分离以及水处理等方面。与普通的块体材料相比，纳微结构材料具有一些特殊的物理化学性质，是当前材料领域的研究热点之一。本论文基于液相的化学合成路线，制备了一系列具有特殊纳微结构的氧化铁材料，通过对其反应过程的研究，分析了其可能的生长机制，并对其在气敏传感器、催化、水处理等方面的应用进行了初步的研究，探讨了其结构与性能之间的构效关系。本论文主要内容归纳如下: (1) 利用碳球作为模板制备了具有多壳层结构的α-Fe2O3空心球。通过调变合成条件实现了对壳层数的调控。利用该方法也可以合成具有多壳层结构的其它金属氧化物空心球如：Co3O4、NiO、CuO、ZnO等，此方法还可以用来制备异质的多壳层空心球。该合成方法简单，重复性好，可控性强，具有一定的普适性。由于具有高的比表面，多孔、中空及多壳结构，多壳层空心球在药物缓释、催化剂载体、气敏等方面有着广泛的应用前景。 (2) 采用溶剂热法制备了纳米粒子组装的三氧化二铁空心球。通过控制反应条件可以得到尺寸均一、单分散的空心氧化铁微球，该空心微球是由纳米棒组装而成。反应时间、EDTA的剂量等因素对样品的形貌、微结构有较大的影响。研究了反应时间对空心球形成过程的影响，推测了空心球的形成机理。在模拟水污染的处理中，该空心结构对无机重金属离子Cr(VI)具有较快、较强的吸附能力，这可能与其较大的比表面积和多孔结构有关。 (3) 在乙二胺的辅助作用下，通过溶剂热法合成了尺寸均一、单分散的柱状α-Fe2O3纳米粒子，在该制备过程中，乙二胺同时作为碱源和模板剂，对纳微结构的形成起到了重要作用。反应时间、乙二胺用量、溶液的pH及表面活性剂等因素对样品的形貌、尺寸有着较大的影响，通过调变相关反应参数可以得到不同形貌及尺寸的氧化铁。对柱状氧化铁的形成过程进行了探讨，研究了不同形貌的氧化铁对高氯酸铵(AP)的催化作用。 (4) 采用溶剂热法制备了表面颗粒为多面体的Fe3O4微球。通过控制反应条件可以得到尺寸均一、分散性较好的四氧化三铁微球。通过对实验条件的选择，实现了四氧化三铁表面颗粒由长方体到八面体的演变。通过对时间演化过程的研究，提出了微球可能的形成机理。研究了组装微球的磁性质及其对重金属离子Cr(VI)的吸附能力。 |
| 英文摘要 | Iron oxide, as a kind of conventional environmentally-friendly material, has been widely employed in various fields such as pigment, sensors, catalyst, electrode material, magnetic separation and water treatment. This dissertation presents a series of various hierarchical and hollow micro-/nanostructured iron oxides (such as single-layer or multi-layer hollow microspheres, mcirocolumns) synthesized via a simple solution-based method. The formation mechanism of these hierarchical and hollow iron oxide nanostructures was also investigated. Moreover, the corresponding structure-dependent properties of the as-obtained hierarchical and hollow micro-/nanostructures are also investigated in this dissertation. The main contents are summarized briefly as follows: (1) We put forward a method to prepare multi-layer hollow hematite microsphere using carbon spheres as template. Layer controllable hollow microsphere is prepared by controlling the reaction conditions. This method can be extended to synthesize other multi-layer metal oxides hollow spheres such as ZnO、Co3O4、NiO、CuO, even hetrogeneous multi-layer metal oxides hollow spheres. Those hollow spheres can be used in the drug delivery、catalyst carrier and gas sensor due to their high BET specific surface area and porous hollow structure. (2) By using N,N-dimethyl formamide and water as co-solvent, hematite hollow microspheres are successfully prepared via one-pot solvothermal method. These hollow microspheres were assembled by hematite nanorods. The effect of the amount of solvent and other reaction parameters (such as reaction time, the amount of EDTA) on the formation of the hollow microspheres is investigated. The formation mechanism of the hollow microspheres is also proposed. Considering the unique hollow structures of the products，the application of the as-obtained hematite hollow structure in Cr(VI) removal is investigated. (3) The size-controlled monodispersed column-like hematite was synthesized via a hydrothermal method with the assistance of ethylenediamine. Here, the ethylenediamine played an important role in the formation of hematite nano/microstructures not only as alkaline but also as a capping agent. The microstructures of the products can be adjusted by varying different reaction parameters (such as the reaction time, the amount of ethylenediamine, pH value, concentration of capping agent etc.). Hematite with different morphology could be synthesized by tuning the reaction conditions. The formation mechanism of the column-like hematite hierarchical structures was investigated. The decompositions ability of the products on ammonium perchlorate (AP) was also investigated. (4) Magnetite microspheres with polyhedra assembled on the surface were successfully prepared by a simple hydro- and solvothermal reduction route. The influence of synthetic conditions on the morphology, structures and size of the microsheres were investigated. The surface morphology of microspheres can be adjusted by controlling the synthetic conditions. The formation mechanism of the microspheres was also investigated by the time-controlled experiment. The magnetic property and the Cr(VI) removal ability of as-obtained microspheres were aslo investigated. |
| 公开日期 | 2013-09-17 |
| 页码 | 113 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1524]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 李军. 氧化铁纳微结构材料的合成及应用研究[D]. 北京. 中国科学院研究生院. 2010. |
入库方式： OAI收割
来源：过程工程研究所
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