【作者】 吕仁江；

【导师】 胡中爱；

【作者基本信息】 西北师范大学 ， 物理化学， 2004， 硕士

【摘要】 一维纳米材料具有一些新奇的电学、光学、磁学和化学性质。在太阳能电池、传感器、催化剂、吸附剂和选择分离等诸多重要技术领域有着广泛的应用前景。因此，一维纳米材料的制备与研究在现代材料科学的研究中占据着非常重要的地位，是材料科学的前沿领域，也处在纳米材料研究的前沿。阳极氧化铝不仅制备工艺简单，而且得到的多孔氧化膜具有孔径分布均匀、孔密度高、空洞之间互相不连通，取向一致的特点，并且可根据实际需要调控孔径大小，是作为模板的良好选择之一。近年来，以多孔阳极氧化铝为模板合成一维纳米结构材料受到了人们的关注，获得了深入地研究。本论文采用阳极氧化铝模板法制备出了几种新型的纳米线，并对它们的形貌、组成、晶体结构及其他一些性质进行了表征。 本论文主要由以下三部分组成： 1．多孔阳极氧化铝的制备和表征 高度有序的纳米孔洞模板是制备纳米线阵列的基础，本文详细研究了高度有序的多孔阳极氧化铝模板的制备工艺。通过二步阳极氧化法得到更加理想的长程有序分布的纳米孔。实验表明，在适当浓度的草酸中，铝电化学氧化形成多孔氧化铝，其表面形貌研究表明，多孔氧化铝膜中孔径均匀，垂直于表面且彼此分立而平行的纳米级微孔，通过扩孔处理可以方便控制孔径大小。这些特性表明，多孔氧化铝是一种很好的制备有序纳米线阵列的模板材料。 在0.3M草酸电解液中，我们得到了孔径60nm，孔密度1.1×10¹⁰的阳极氧化铝膜，并采用原子力显微镜（AFM）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和X射线电子衍射观察了阳极氧化膜纳米孔的形貌和结构。我们制备的阳极氧化膜非常适合作为一维纳米材料的模板。 2．模板法制备CeO₂纳米线阵列 稀土元素特殊的电子构型，使其具有独特的性质及广泛的应用。为进一步了解4f电子的运动规律，使稀土材料具有新的和更高的应用价值，则稀土化合物纳米材料的合成、电子结构、功能特性和应用的研究将是一个迫切而又极为重要的研究课题。CeO₂是一种廉价而用途极广的材料，如用于发光材料、抛光剂、紫外吸收材料、汽车尾气净化催化剂、玻璃的化学退色剂、耐辐射玻璃、永磁体、电子陶瓷等，其纳米化后将出现一些新的性质及应用，如ceOZ纳米晶是细胞色素C的良好的催进剂，还用作zro:陶瓷的稳定剂，由于ceo:折射率高，稳定性好，常用于制备减反射膜等。可见，CeO:纳米晶的用途极其广泛，合成其是十分必要的。 以阳极氧化铝膜护AO)为模板通过新的方法合成了ceo:纳米线阵列，新的方法一阴阳离子通过氧化铝膜的有序纳米孔道逆向迁移，在纳米孔中相遇反应生成一维纳米结构。从透射电镜(几玛图像可以得知ceo:纳米线直径大约60nln，与所用膜的孔径相符，电镜选区衍射（s AED）显示所选的CeO:纳米线为单晶结构。通过扫描电子显微镜（s EM）测得Ceo:纳米线丰富并且均一。用X射线电子衍射观察了ceo:纳米线是立方晶体结构。通过x射线光电子能谱（”S）证实了化学计量的Ceo:己经形成。还利用紫外可见分光光度计考察了它的光学性质。 3.模板法制备聚苯乙烯纳米纤维阵列 用铝阳极氧化法制备了三氧化二铝膜，以其为模板合成了聚苯乙烯（PS）纳米纤维，通过扫描电镜（sE码、x射线电子衍射（XRD）、傅立叶红外光谱仪（盯一IR）对聚苯乙烯伊s）纳米纤维进行了表征。结果表明，合成的聚苯乙烯纳米纤维具有高度取向性、有序性，纳米纤维的长度和直径取决于模板的厚度和孔径的大小，并验证了此方法的可行性。更多还原

【Abstract】 A great deal of attention has been paid to one-dimensional nanostructural materials due to their novel electrical, optical, magnetic and chemical properties. They have significant potential applications in many important advanced technologies, such as solar energy conversion, chemical sensor, catalysis, absorption and separation. Anodic aluminium oxide (AAO) membrane, which is usually fabricated by anodic oxide of Al, has uniform parallel pores and high pore density. Furthermore, the pore diameter is controllable according to practical needs. These characteristics allow the use of AAO as a template, which is attractive for synthesis of one-dimensional nanostructural materials. In this thesis, several new kinds of nanowires were prepared by the AAO template technique. The morphology, chemical compositions, crystal structures and some properties of these obtained nanowires were systemically characterized.This thesis consists of three sections as follows:First, the preparation and characterization of porous anodic alumina. Template is the effective tools for preparing nanowire arrays. In this dissertation, the fabricating process of AAO template was discribed in details. We have got porous alumina in the aqueous solution of oxalic acid with appropriate concentration through two-step anodic oxidation. The resultant porous alumina membranes have relatively ordered hexagonal pore arrays, which consist of separated nanopores perpendicular to the film surface, parallel to each other and with uniform pore diameter. The pore diameter can be controlled by varieties of immersion time in acid. Because of the above features, the porous alumina was used as a desirable template to fabricate ordered nanowire arrays. In our experiments, the template with pore diameters of 60 nm, and with a pores density of l.lxlO10 has been obtained in 0.3 M oxalic acid. The anodic oxide film was observed by using an atomic force microscope (AFM), the scanning electron microscopy (SEM), a transmission electron microscope (TEM) and the X-ray diffraction (XRD).Second, template synthesis of CeO2 ordered nanowire arrays. Rare earth elements have unique properties and extensive applications owing to their special electronic configuration. In order to further understand the movement regularity of 4f electrons and to make rare earth materials have new and better practical value, research on synthesis, electronic construction,functional properties and applications of rare earth compound nanomaterials is urgent and important. CeO22 is used as optical materials, polishing agents, ultraviolet absorption materials, the cleaning catalyst of car’s waste gases, chemical decolorant of glass, radiation-resisting glass permanent magnet, electronic ceramics etc. If it is processed into nanoparticles, it will exhibit some novel properties led to varied applications. For example, CeO22 nanocrystal is a better promoter of cytochrome C and the stabilizer of ZrO22 ceramics. Because of its high index of refraction and good stability, it is used to produce reduced reflection film. In conclusion, it is important to synthesize CeO22 nanoparticles because of its extensive use.Ordered CeO2 nanowire arrays embedded in anodic aluminium oxide (AAO) membrane were fabricated by a novel technique, in which anions and cations conversely migrate into the hexagonally ordered nanochannels of the AAO and react inside the channels to form one-dimensional nanostructures. The transmission electron microscopy (TEM) images show that CeO2 nanowires are about 60 nm in diameter, which correspond to the pore sizes of the membranes used. The selected-area electron diffraction (SAED) pattern indicates that the nanowires selected are single crystals. The scanning electron microscopy (SEM) images show that the resultant nanowires are abundant and uniform. The X-ray diffraction (XRD) spectra indicate that the CeO2 nanowires are cubic crystalline structure. The X-ray photoelectron spectroscopy (XPS) spectra data demonstrate that stoichiometric CeO2 is formed. It is found that the更多还原