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多孔氧化物纳米材料的溶剂热合成、表征及应用研究
Solvothermal Synthesis, Characterization and Application of Porous Oxide Nanomaterials
【作者】 梁鑫;
【导师】 钱逸泰;
【作者基本信息】 中国科学技术大学 , 无机化学, 2009, 硕士
【摘要】 本论文本论文包括两部分工作:一、在乙二醇溶剂体系中合成了具有纳米分级结构的前驱体,然后通过后续的热处理过程得到了比表面积很大的γ-Fe2O-3微球。以罗丹明B作为目标污染物,研究了所合成的γ-Fe2O3在污水处理领域中的应用;二、在乙醇与水形成的二元混合溶剂体系中对β-Ni(OH)2微球和纳米片进行了可控制合成,然后经过随后的热处理得到了形貌保持的多孔的三维组装花状结构的NiO微球和NiO纳米片。主要内容归结如下1.多孔软磁材料是是软磁材料家族里应用范围很广的一员。这种材料在与表面相关的领域有巨大的应用潜力。在本文中,我们通过溶剂热合成和后续的热处理技术,成功地制备了比表面积为82.7 m2/g的γ-Fe2O3微球。从测试结果可以看出,该种γ-Fe2O3微球的剩余磁化强度(Mr)仅有0.7 emu/g,几乎没有磁记忆能力。在污水处理过程中,目标污染物罗丹明B通过吸附、脱附循环被除去。该种微球在一个磁铁的作用下很容易地实现循环,而且在室温下的乙醇中可以实现再生。2.通过混合溶剂热法成功制备了花状β-Ni(OH)2微球和β-Ni(OH)2纳米片,然后经过随后的热处理得到了形貌保持的多孔的三维组装花状结构的NiO微球和NiO纳米片。通过调节混合溶剂中水与乙醇的比实现了β-Ni(OH)2的形貌可控合成。发现只有当水与乙醇的体积比为1比9时,合成的β-Ni(OH)2为纳米片组装成的微球;其余比例时得到的产物均为β-Ni(OH)2纳米片。用XRD、TEM、SEM等对样品进行了表征,并研究了这两种形貌的β-Ni(OH)2和NiO的磁学性质、比表面性质和光学性质。
【Abstract】 In this dissertation, our work concludes two parts. Firstly, the precursor with hierarchical nanoarchitecture was obtained by solovethermal method in glycol, while the maghemite microsphere with large surface area was receieved by the subsequent calcining process. The application of maghemite microsphere in the water treatment was studied, using Rhodamine B as a model organic pollutant. Secondly, in the mixed solventsystem made of H2O and ethanol, the controllable synthesis ofβ-Ni(OH)2 flower-like microspheres and nano sheets were realized. Porous NiO microspheres and porous NiO nanosheets were obtained by the subsequent calcining process. The main points list as follows:1. Porous soft magnetic material is a member of soft magnetic material family having large surface area. This kind of material has vast potential in the surface-related applications. In this paper, a kind of maghemite (γ-Fe2O3) with large surface area, 82.7 m2/g, specifically, was obtained by solvothermal method and subsequent calcining process. As shown in the test results, the maghemite microsphere has no magnetic memory in the magnetic field since the residual magnetization is only 0.7 emu/g. In the waste water treatment process, Rhodamine B, a model organic pollutant in the water, was removed through the adsorption and desorption cycles by the maghemite microspheres. The maghemite microspheres in the water can be recycled easily by a magnetic separation procedure and regenerated in ethanol at room temperature.2. in the mixed solventsystem made of H2O and ethanol, the controllable synthesis ofβ-Ni(OH)2 flower-like microspheres and nano sheets were realized. Porous NiO microspheres and porous NiO nanosheets were obtained by the subsequent calcining process. The morphology ofβ-Ni(OH)2 was controlled by the volume proportion between the H2O and ethanol. When the proportion was 9 to 1,β-Ni(OH)2 was microsphere which was self-assembled by nanosheets. Except that, the morphology ofβ-Ni(OH)2 was nanosheet. The samples were characterized by XRD, TEM and SEM. The magnetic, optical and surface area properties of the synthesizedβ-Ni(OH)2 and NiO were also studied.
【Key words】 porous oxide; γ-Fe2O3; water treatment; β-Ni(OH)2; NiO;