【作者】 郭玉国；

【导师】 张亚利；

【作者基本信息】 青岛大学 ， 材料学， 2001， 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。本论文采用电化学模板合成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；发展了一种用紫外－可见光分光光度法分析电沉积在导电玻璃上的Ni-Fe合金镀层的方法；用模板脉冲电沉积法制备了Fe20Ni80/ Ag多层纳米线，并对它的形貌进行了初步表征。一维纳米半导体材料因其独特的结构和性质，在电子和光电子器件的应用及基础理论方面都有重要的研究价值，因而引起人们广泛的研究兴趣。我们以多孔阳极氧化铝为模板，利用直流电沉积技术，制备出CdSe 、Te和CdTe等半导体纳米线：一、深入研究了电沉积CdSe薄膜的条件，发现了CdSe薄膜的取向诱导结晶效应，找到了制备结晶良好，基本无氧化的六方CdSe薄膜的方法。<WP=3>以导电玻璃为基底，利用恒流电沉积技术，在DMSO体系中，分别在130℃、140℃、150℃、160℃、170℃和185℃下制备了CdSe薄膜，并对其进行了SEM、XPS、XRD和光吸收性质的表征。重点研究了沉积温度和退火处理对CdSe薄膜的组成、氧化程度、晶体结构和光吸收性质等方面的影响。发现140℃制备的样品中（001）面高度取向，禁带宽度明显蓝移，经退火处理后这些高度取向的晶粒可诱导结晶，使晶界消失，晶粒急剧增大，完善程度提高，得到结晶良好，基本无氧化的六方CdSe薄膜。二、用模板法恒电流沉积制备了CdSe半导体纳米线，首次得到了结构完整的单晶CdSe纳米线。以银作为导电基底的多孔阳极氧化铝为模板，在DMSO体系中，用恒流电沉积方法，于不同温度下分别在直径为10，20，50nm的AAO模板中制备出了CdSe纳米线，并对它们进行了退火处理。SEM、TEM、EDAX、XRD、ED、HREM分析的结果表明，所得CdSe纳米线为六方晶型，晶体的（001）晶面沿平行于基底的方向择优生长，且随沉积温度的降低，这种择优生长的趋势越来越强；纳米线晶体在生长时，由于受AAO模板孔径的限制，形成c轴方向拉长的晶粒，其长径比达5∶1以上；晶体的大小和完善程度随沉积温度的降低而增大，185℃沉积得到多晶六方CdSe纳米线，而140℃沉积时可得到六方CdSe单晶纳米线。三、首次制备出了Te和CdTe单晶纳米线，并对其晶体结构进行了详细表征。以银作为导电基底的多孔阳极氧化铝为模板，在乙二醇体系中，用恒流电沉积方法，制备出了Te和CdTe纳米线。SEM、TEM、EDAX、XRD、ED、HREM分析的结果表明，所得Te和CdTe纳米线直径、长度均匀，平行排列；Te纳米线为纯净的六方单晶Te纳米线；CdTe纳米线为从内到外结晶好，没有氧化层包裹的六方CdTe单晶，且其线轴方向与（002）方向一致。四、首次用模板脉冲电沉积方法制备了Fe20Ni80/Ag多层纳米线，并对它的形貌进行了初步表征。近年来具有巨磁电阻效应的各种多层结构颇受人们青睐，其研究对象也已从传统的连续多层膜和间断多层膜发展到了多层纳米线。Ag基多层纳米线是巨磁电阻多层纳米线中较为重要的一类。以多孔阳极氧化铝为模板，<WP=4>我们利用脉冲电沉积技术，制得了Fe20Ni80/Ag多层纳米线，并用SEM和TEM对它们的形貌进行了初步表征。五、找到了一种快速测定铁镍镀层中铁镍含量的紫外－可见光分光光度法。利用三价铁与EDTA和H2O2形成稳定的深紫色三元络合物，在氨性溶液中，当有氧化剂存在时，镍与丁二酮肟形成酒红色的络合物，用吸收光度法可分别在519nm和538nm波长处测定铁、镍的含量，Fe和Ni的相对标准偏差分别为0.95％和1.2％；对实际样品的测定结果与XPS分析一致。表明该法具有精密度高，灵敏度好，设备简单，操作方便等优点，对同时需要测定试样中铁、镍含量的场合非常适用。更多还原

【Abstract】 A great deal of attention has been paid to the preparation and characterization of one-dimensional nanostructrue. These materials have significant potential applications in many important advanced technologies, such as solar energy conversion, chemical sensor, catalysis, absorption and separation, and they also have some novel electrical, optical, magnetic and chemical properties. In this thesis, several new kinds of nanowires were prepared by the template technique using electrochemical methods. The morphology, chemical compositions, crystal structures and some properties of these obtained nanowires were systemically characterized. <WP=6> Because of their novel properties and unique structures, one-dimensional nanostructrue semiconductor materials have generated a tremendous amount of interests in fundamental and potential promising applications in electronic and photoelectronic devices. We fabricated CdSe, Te and CdTe nanowires by direct current (dc) electrodeposition in porous anodic aluminum oxide (AAO) templates. (1) CdSe thin film has been produced by electrochemical method on conductive glass in dimethylsulfoxide (DMSO) system under 130℃, 140℃, 150℃, 160℃, 170℃ and 185℃, and characterized by scanning electron microscopy (SEM), X-ray photoelectron spectrum (XPS), powder X-ray diffraction (XRD), and optical absorption measurement. The effects of bath temperature and heat treatment on the morphology, chemical compositions, crystal structures and optical properties have been discussed. (2) Uniform CdSe nanowire arrays with controllable lengths have been fabricated by dc electrodeposition in the AAO templates with Ag as their conductive substrates from DMSO system under different temperature. The nanowires with the diameters from 10nm to 50nm, and the lengths from 1(m to 20(m have been obtained. SEM, transmission electron microscopy (TEM), X-ray energy-dispersion analysis (EDAX), XRD, electron diffraction (ED) and high-resolution electron microscopy (HREM) were used to investigate the morphology, atomic composition and crystal structure of the nanowires. The hexagonal CdSe nanowires with single crystal structure have been obtained in DMSO under 140℃. (3) Semiconductor Te and CdTe nanowires embedded in AAO templates were fabricated for the first time by dc <WP=7>electrodeposition in ethylene glycol. SEM and TEM with EDAX assisted were used to study the morphology and chemical compositions of the nanowires. The diameters and lengths of the nanowiers are uniform. XRD, ED and HREM shows that hexagonal Te and CdTe nanowires were obtained in the experiments, and they both have a single crystal structure with uniform (001) growth direction. Much interest has focused, in recent years, on the developments of magnetoresistance in various multistructures, especially on the giant magnetoresistance of multilayered nanowires. Fe20Ni80/Ag multilayered nanowires were successfully obtained for the first time by pulse electrodeposition in the AAO templates, and their morphologies were characterized by SEM and TEM. In addition, we use spectrophotometric to study the compositions of nickel-iron alloy prepared by electrodeposition, and the main results are as follows: Iron(Ⅲ) forms a stable deep purple complex with ethylenediaminetetraacetic acid disodium salt (EDTA) and hydrogen peroxide in aqueous solution at PH=10.7-11.3; Nickel(Ⅱ) forms a red complex with dlacetyl dioxime in aqueous ammonia when an oxidation (iodine) exists; thus the amount of iron(Ⅲ) and nickel(Ⅱ) can be determinated by the absorption of their complexes at 519nm and 538nm respectively.更多还原