模板法制备过渡金属氧化物空心微球及其性能研究

发布时间：2018-04-18 20:34

  本文选题：模板法 + 空心微球　； 参考：《安徽大学》2011年硕士论文

【摘要】：近年来,空心微球在催化、化妆品、药物和基因传递、氢气的生产和存储、光子学、光电和充电电池方面的广泛应用,引起了人们对其制备和特性研究的极大兴趣。而在诸多制备空心微球的方法中,模板法的使用最为广泛,因为理论上只要找到一种合适的模板材料,就可以制备尺寸、外形、化学组分可控的空心结构。因此,深入而细致地研究模板法制备空心微球的原理及工艺,具有非常现实的应用价值。由于氧化锌和铁氧体材料在电子器件、半导体材料、生物工程、光电子学、微波吸收等方面的重要应用,探索和制备具有空心结构的氧化锌和铁氧体材料是目前材料学、光学、电磁学、生物学、化学等领域中的研究热点。 本文利用模板法制备了空心结构的ZnO微球和CoFe2O4微球。围绕着空心微球的制备,文章着重讨论了制备工艺过程对微球结构及形貌的影响,论述了不同烧结温度对CoFe2O4微球磁学特性的影响。主要研究内容如下： 1.利用水热法制备胶体碳球模板,并对其结构形貌进行表征。表征结果显示,模板颗粒为球形、非晶颗粒,且尺寸均匀。 2.采用模板法制备了具有纤锌矿结构的多晶ZnO空心微球,系统的研究了不同工艺参数对空心微球结构及形貌的影响。当烧结温度不低于450℃时,可以获得成分纯净的ZnO空心球；通过改变模板颗粒在Zn2+离子溶液中的静置时间,可以对空心微球的尺寸及表面形貌进行调控；Cl-离子及N03-离子的加入,会对ZnO空心微球的形貌有着重要的影响 3.利用水热法制备了具有尖晶石结构的钴铁氧体多晶颗粒,详尽的研究了水热反应温度及反应时间对其结构及磁性能的影响。不同的反应温度会对钴铁氧体颗粒的成分产生重要影响。随着反应温度的升高,钴铁氧体颗粒的磁性增强；通过改变水热反应时间,可以对钴铁氧体的饱和磁化强度、矫顽力、剩余磁化强度进行调节。我们认为,O2-离子与磁性阳离子间的电子轨道杂化是产生钴铁氧体晶核的诱因。 4.通过模板法制备出具有尖晶石结构的多晶钴铁氧体空心微球,深入而细致的研究了不同烧结温度对空心微球的结构、形貌及磁性能的影响。通过改变烧结温度,钴铁氧体空心微球的形貌发生变化。当温度达到550℃及以上时,微球逐渐由空心结构转变为多孔结构。实验还发现,当烧结温度达到450℃时,微球中出现α-Fe203反铁磁相。通过分析,我们认为Fe3+[(Co1_xFex)2+Fe3+]04的生成是导致相变发生及样品磁性能变化的主要原因。
[Abstract]:In recent years, the wide application of hollow microspheres in catalysis, cosmetics, drug and gene transfer, hydrogen production and storage, photonics, photoelectricity and rechargeable batteries has attracted great interest in their preparation and characterization.Among the many methods of preparing hollow microspheres, template method is the most widely used, because in theory, as long as a suitable template material is found, the size, shape and chemical composition of the hollow structure can be controlled.Therefore, it is of great practical value to study the principle and technology of hollow microspheres prepared by template method.Because of the important applications of zinc oxide and ferrite materials in electronic devices, semiconductor materials, bioengineering, optoelectronics, microwave absorption and so on, the exploration and preparation of zinc oxide and ferrite materials with hollow structure are current materials.The research focus in electromagnetism, biology, chemistry and so on.In this paper, hollow ZnO microspheres and CoFe2O4 microspheres were prepared by template method.Around the preparation of hollow microspheres, the influence of the preparation process on the structure and morphology of the microspheres was discussed, and the effects of different sintering temperatures on the magnetic properties of CoFe2O4 microspheres were discussed.The main contents of the study are as follows:1.Colloidal carbon sphere template was prepared by hydrothermal method and its structure and morphology were characterized.The results showed that the template particles were spherical, amorphous and uniform in size.2.Polycrystalline ZnO hollow microspheres with wurtzite structure were prepared by template method. The effects of different process parameters on the structure and morphology of hollow microspheres were studied systematically.When the sintering temperature is not lower than 450 鈩，

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