【作者】 吕伟；

【导师】 吴佑实；

【作者基本信息】 山东大学 ， 材料学， 2006， 博士

【摘要】 纳米材料是当今新材料研究领域中最富有活力、对未来经济和社会发展有着重要影响的研究对象，也是纳米科技中最活跃、最接近应用的重要组成部分。纳米尺度下所具有的诸多性能，如量子尺寸效应、小尺寸效应以及表面效应等会对低维纳米材料的输运和光学性能产生重要影响，同时会在低维纳米体系中实现比常规体材料更为优越的电、光、磁和机械性能。近年来，对纳米材料及其性能的研究取得了巨大的进步，但仍有很多问题需要解决，也充满了机遇。 目前，如何采用有效的制备方法合成纳米材料并对其微结构和有关性能进行研究是不少研究人员关注的问题。 本论文工作主要采用水热法和气相沉积法制备ZnO、CeO₂、GaN和Bi₂O₃等纳米材料，采用X射线粉末衍射仪、扫描电镜、透射电镜、拉曼散射光谱仪、傅立叶变换红外光谱仪及紫外光谱仪等分析测试手段进行分析，并对其形貌特征、微结构、部分物理性质和机理进行了系统的研究，研究分析了工艺条件、制备方法等对ZnO、CeO₂、GaN和Bi₂O₃纳米结构的影响。主要研究结果如下： 氧化锌作为代表性第三代宽带隙半导体材料，对其纳米材料的研究引起研究人员的广泛关注。论文采用水热法，以ZnCl₂和NaOH为原料得到[Zn（OH）₄]^2-溶液，以此溶液为前驱体，在不同的原料比和反应条件下制备出了一系列的一维纳米材料——ZnO纳米棒。用扫描电镜对其形貌对比分析，用透射电镜对其微结构进行了表征，表明所制备的一维纳米材料是六方单晶氧化锌纳米棒。研究分析了添加剂PEG对ZnO纳米晶的析出、生长速率和成长形态等特征的影响机理，PEG分子吸附Zn²⁺阳离子，使表面电荷密度增加、表面张力降低、成核能垒降低从而提高ZnO纳米晶析出与生长速率，PEG对ZnO晶体生长取向的诱导作用和成长形态特征有重要影响。研究了水热反应中的溶液环境对粒子形态和尺寸的影响情况，醇—水的环境可以控制ZnO₄^2-从液相到晶体表面的释放速度，得到形态均匀的纳米棒。 纳米稀土氧化物CeO₂是一种用途极广的新型功能材料，在整个稀土的应用中占举足轻重的地位，其应用开发前景十分广阔。以水、乙醇和乙二胺为溶剂用水热法制备了单晶CeO₂纳米棒。利用XRD和SAED进行了物相分析，利用高分辨透射电镜进行了形貌分析，结果表明所得到的CeO₂纳米棒为立方萤石结构且CeO₂纳米棒粒径分布窄，比较均匀，表面光滑。研究了溶剂乙醇和乙二胺的共同作用对反更多还原

【Abstract】 Nanomaterials have stimulated great interest because of its unique properties including surface effect, small size effect and quantum dimension effect, which differ from those of bulk substances and single molecular. The promising application value in areas such as electronics, optics, chemistry, ceramics, biology and medicine invokes great interest all over the world. Synthesis and characterize of zero-dimensional materials have been obtained great achivement since the 1980s. In recent years, there are great progress in one-dimensional （1D） and two-dimensional （2D） nanomaterials of synthesis and characterize. But the synthesis of 1D and 2D materials are still challenging. There are still some difficulities in controlling effictively the morphology and microstructure of nanomatirials.In this paper, ZnO, CeO₂, GaN and Bi₂O₃ nanomaterials have been synthesized successfully by hydrothermal method and chemical vapor deposition method. Their morphologies, microstructures have been charactirized, and some physical properties and growth mechanism have been researched systematically. The main results are as follows:ZnO nanorods have been fabricated by the chemical reaction of ZnCl₂ solution and NaOH solution. The ZnO nanorods are characterized with scanning electron microscopy （SEM）, energy-dispersive X-ray spectroscopy （EDX）, transmission electron microscopy （TEM） and powder X-ray diffraction （XRD）. The results show these one-dimensional nanorods are single crystal with hexagonal structure. Additive reagent PEG is very important for the formation of ZnO nanorods. The PEG molecules adsorb Zn²⁺ and cause the increasement of the surface electronic charge density, the dicreasement of surface tension and nucleation energy. PEG has an important inductive function on growth tendency of ZnO nanostmctures. How the solution environment affects the morphology and dimension during the synthesis process of ZnO nanostructures has been discussed. The speed of ZnO₄^2- from liquid to crystal surface can be controlled in the environment of Alcohol-water, which is helpful to obtain uniform nanorods. If there is no alcohol in the solution, the speed of ZnO₄^2- from liquid to crystal surface can’t be controlled, and only big asymmetry microrods can be obtained.更多还原