【作者】 孔超；

【导师】 胡中爱；

【作者基本信息】 西北师范大学 ， 物理化学， 2006， 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阔的应用前景。因此，一维纳米材料的制备方法一直受到人们的广泛关注，也是纳米科学技术领域的重要研究内容。多孔阳极氧化铝不仅制备工艺简单，而且得到的多孔阳极氧化铝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。本论文以多孔阳极氧化铝为模板，用比较简单有效的方法制备出了几种材料的纳米线，并对它们的形貌、组成、晶体结构进行了表征。同时，还对银纳米线阵列电极的电化学性能进行了初步研究。本论文主要由以下四部分组成：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、一步阳极氧化法分别在草酸溶液和磷酸溶液中对铝箔进行氧化得到不同孔径的多孔氧化铝模板。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（XRD）对阳极氧化膜纳米孔的形貌和结构进行表征。结果表明，在适当浓度的草酸溶液中，所得多孔阳极氧化铝模板，其纳米微孔分布较均匀，垂直于表面且彼此分立而平行，孔径均匀约为60nm，孔密度约为1.1×10¹⁰个/cm²；而在磷酸溶液中，所得多孔阳极氧化铝模板，其纳米微孔分布均匀度较差，孔径较均匀，平均约为120nm。这些特性表明，在草酸电解液中，通过控制电压所得多孔阳极氧化铝是一种很好的制备有序纳米线阵列的模板材料。2．模板法合成Ag纳米线阵列金属Ag具有良好的导电性和传热性，并且对一些化学反应有显著的催化作用，其一维纳米材料有望在制作微型器件的功能元件和连接元件等方面有广阔的应用前景，同时由于其特殊的形貌和表面性质，使它们在电化学和催化方面的应用也倍受关注。以多孔阳极氧化铝为模板，用乙二醇作为还原剂，通过条件控制将Ag⁺在模板的纳米孔道内还原并进行限域生长，制得了无缺陷Ag纳米线。用X射线衍射光谱（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等检测手段对产物进行表征，结果表明，所得Ag纳米线具有面心立方的晶体结构，纳米线阵列排列整齐，长度可达10μm，单体纳米线的直径大约为60nm。3．Ag纳米线阵列电极的组装及其电催化活性借助多孔阳极氧化铝模板自身高度有序的特征，利用无电沉积法将Ag沉积到模板孔洞内，制备了Ag纳米线阵列，再将Ag纳米线阵列组装到导电基体，得到了Ag纳米线阵列电极，并将Ag纳米线阵列电极作为工作电极，用循环伏安法测定了其的电化学性能。结果表明，所制Ag纳米线阵列电极对亚甲基兰有很好的电催化活性。4．模板法合成Sr₂CeO₄纳米线阵列以多孔阳极氧化铝为模板，采用逆向迁移技术，在模板的纳米孔道内反应形成一维纳米结构前驱体，再经后续处理，制得了Sr₂CeO₄纳米线。通过X射线衍射光谱（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等检测手段对产物进行表征，结果表明，所得Sr₂CeO₄纳米线阵列排列整齐，单体纳米线的直径大约为60nm，长度可达3μm。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. So the synthesis of one-dimensional nanostructural materials attracted much more interest and become the focus of a rapidly growing scientific community. 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 to synthesize one-dimensional nanostructural materials. In this thesis, several kinds of nanowires were prepared by using anodic aluminium oxide （AAO） template. The morphology, chemical compositions, crystal structures of these obtained nanowires were systemically characterized. In addition, the Ag nanowire array electrode was also assembled and its electrochemical performances were measured for methylene blue.This thesis consists of four sections as follows:（1） The preparation and characterization of porous anodic alumina.Template is the effective tools for preparing nanowires arrays. In this paper, the fabricating process of AAO template was described in details. AAO templates with different pore diameter were produced in different electrolytes （oxalic acid and phosphoric acid） by different methods （two-step anodic oxidation, one-step anodic oxidation）. The anodic oxide film was characterized by using an atomic force microscope （AFM）, the scanning electron microscopy （SEM）, a transmission electron microscope （TEM）, and furthermore the its crystal conversion was also analyzed by the X-ray diffraction （XRD）. The results show that AAO template prepared in oxalic acid have high ordered pore arrays, which consist of the separated nanopores perpendicular to the film surface, parallel to each other and with uniform pore diameter. The pores are about 60 nm in diameters and 1.1×10¹⁰ pores/cm² in density, while AAO template produced in phosphoric acid have pore arrays in less order and pores with about 120 nm in diameters. Because of the above features, the AAO template obtained in 0.3M oxalic acid by controlling anodic voltage was used as a desirable template to fabricate nanowire arrays or freestanding nanowires.（2） Template synthesis of Ag ordered nanowire arrays.Silver has high electrical and thermal conductions, and exhibits conspicuous catalysis for a lot chemical reactions. The one-dimensional nanostructures of silver are expected to be used as interconnectors and functional units of devices with nanoscale dimensions. Besides, they could play an important role in chemical catalysis and electrocatalysis due to their peculiar structure and high surface activation.Ordered flawless Ag nanowires arrays were fabricated using an effective method, in which Ag ions and glycol react to form silver nanonuclei inside the nanochannels of AAO templates, and then grow into Ag nanowire by confining growth. The nanowires were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）. The TEM images show that Ag nanowires are abundant and uniform, and the diameter of the Ag nanowires is about 60 nm, which correspond to the pore sizes of the templates used. The SEM images show that the Ag nanowires are abundant and well-ordered in large-area, and up to 10μm in length. The data of X-ray diffraction indicate that the silver nanowire have face-centered-cubic structure.（3） Preparation and electrocatalytic activities of Ag nanowire array electrodeOrdered Ag nanowires arrays were generated by electroless deposition in AAOtemplates. Ag nanowire array electrode was prepared by assembling Ag nanowires arrays onto the surface of kryptol. Electrocatalytic activities of Ag nanowire array electrode for methylene blue was investigated by means of cyclic voltammertry, in which Ag nanowire array electrode was used as the working electrode. Cyclic voltammograms exhibits high electrocatalytic activities of methylene blue on the Ag nanowire array electrode.（4） Template synthesis of Sr₂CeO₄ ordered nanowire arrays.Ordered Sr₂CeO₄ nanowire arrays embedded in AAO templates were fabricated by a converse transport technique that precipitations were shaped into one dimension structure in the hexagonally ordered nanochannels of the AAM and changed into the Sr₂CeO₄ nanowire by the subsequent treatment. The nanowires were characterized by X-ray diffraction （XRD）, scanning electron microscopy images （SEM）, transmission electron microscopy （TEM）. The TEM images show that Sr₂CeO₄ nanowires are about 60 nm in diameter and up to 20μm in length. The SEM images show that the Sr₂CeO₄ nanowires are abundant and uniform.更多还原