【作者】 杜进；

【导师】 钱逸泰；

【作者基本信息】 中国科学技术大学 ， 无机化学， 2008， 博士

【摘要】 本论文旨在探索有机物辅助下无机功能纳米材料的液相合成途径,在对文献综合分析的基础上,结合本实验室的现有条件,选择了水热溶剂热合成以及温和条件（室温）下的化学合成为研究内容。通过对表面活性剂,混合溶剂,高分子添加剂等的使用,制备了金属良导体（Cu）,硫属半导体（ZnSe,ZnTe）和过渡金属氧化物（Mn₃O₄,Co₃O₄）等多种功能材料的纳米结构,研究了产品的形貌、晶体结构和影响因素等,初步探讨了不同形貌结构对材料的一些物理性质的影响。内容简要归纳如下:1.通过表面活性剂十二烷基苯磺酸钠（SDBS）的辅助作用,利用CuCl的歧化反应水热途径合成出了直径大约在300nm空心球状的Cu纳米粉末。实验显示SDBS的存在和浓度对该结构的形成至关重要,分析认为其至少起着两方面的作用:一是做为纳米颗粒的稳定剂:二是形成胶团做为空心球的模板。2.对混合溶剂热法作了进一步的发展,以乙二胺和水合肼的混合液作为溶剂,通过溶剂热和后期热处理结合的方法,合成了放射状花形图案排列的ZnSe的纳米片和ZnTe纳米棒束。实验结果显示乙二胺配合能力、结构导向能力和水合肼的还原能力等性质,以及溶剂的组成比对样品的形貌都起到重要作用,对ZnSe样品的PL光谱做了分析。3.借助特殊结构分子辅助的反应途径合成了Mn₃O₄纳米颗粒和纳米棒。以醋酸锰作为一种有效的锰源,室温沉淀自氧化途径得到高质量的Mn₃O₄胶状纳米颗粒。所得产品结晶性良好,催化氧化CO的性能良好。基于PEG-20000的还原性和结构导向作用,在180℃水热反应20个小时后结合特殊的后期热处理制备出Mn₃O₄纳米棒。实验发现PEG-20000的使用和煅烧条件对产品的物相纯度和形貌有至关重要的影响,磁性研究发现产物的居里温度与块材料一致,但低温下的剩余磁化率和矫顽力改变较大。4.进一步发展了配位化学在水热技术中的应用,采用在碱性有机物溶液中水解钴盐,然后加以热处理的方法,高产率地合成了均匀的Co₃O₄纳米线和形貌整齐的有三维有序的Co₃O₄纳米花。深入研究了试剂的浓度、反应时间、矿化剂、不同的胺盐和煅烧升温速率等反应参数分别对所形成的络合物前驱体和终产物的形貌影响。该络合物途径水热法,即通过选择合适的络合试剂及反应介质制备形貌可控的前驱体样品,随后结合后期热处理的合成技术,有望用于其它过渡金属氧化物纳米功能材料的合成。更多还原

【Abstract】 In this dissertation, organic compounds assisted solution-based chemical routes were developed to prepare low-dimensional inorganic functional nanomaterials. Based on a wide and in-depth literature investigation, combined with the equipments and other conditions of our laboratory, the hydrothermal and solvothermal system or some mild synthesize conditions （room temperature） were selected as the research field. Through the use of surfactant, mixed solvents and polymer, a series of functional material nanostrutal such as metal （copper）, sulfant semiconductors and transition metal oxides have been obtained. The morphologe, crystal structure and effective conditions of the products have been studied. In addition, the influences of different morphologies on their physics properties have also been investigated. The main points are summarized as follows:1. A surfactant-assisted method was used to prepare hollow spherical copper powders with an average size of about 300 nm in diameter from copper monochloride. The existence and the concentration of SDBS were important to the formation of hollow spheres. The surfactant SDBS was believed to play roles on at least two aspects: suppressing the aggregation of metal nanoparticles in initial stage of crystal growth, and construct the micelles to serve as the temple for the hollow spheres.2. The precursor of novel flower-like pattern of radially aligned ZnSe nanoflakes and ZnTe nanrod bundles were synthesized via a facile solvothermal method in a mixed solvent of ethylenediamine and hydrazine hydrate. After thermal treatment of the precursor the metastable wurtzite phase ZnSe nanoflakes and the cubic sphalerite phase ZnTe nanorods sample were obtained. It was found that the strong polarity, strong chelation of ethylenediamine and strong reducing ability of N₂H₄ as well as the ratios of the solvent components were of great importance for the formation of the final structures. The PL spectrum of the as-prepared ZnSe sample was investigated.3. Quasicubes and rodlike of Mn₃O₄ nanostrcutures were obtained through the use of certain molecule with special structure respectively. As a special reagent, manganese acetate was introduced to the system to produce Mn₃O₄ nanopaticles via a facile and environmentally benign route in water by naturally oxidized reaction. The as-synthesized sample, which is well crystallized, showed good catalytic performance in the oxidation of carbon monoxide. Mn₃O₄ nanorods have been prepared by special calcining of the precursor , which was hydrothermally prepared by the reaction of PEG-20000 and KMnO₄ at 180℃for 20 h. Both PEG-20000 and the calcinations condition have key effects on the morphology and phase purity of the product. The magnetism measurements showed that the curie temperature of these nanorods agrees with the bulk material, whereas the remnant magnetization and coercivity are different.4. Based on the further development of introducing some special coordination structure into hydrothermal reaction system uniform Co₃O₄ nanowires and Co₃O₄ nanoflowers were obtained in high yield by the use of organic compounds and the later heating treatment. The effects of the important experiment parameters such as concertations of the reagent, reaction time, mineralizer, different kinds of amine and the heating rate on the morphology of the precursors and the final products were deeply investigated. Such a hydrothermal route using certain coordinate reagent and selected reacting enviroment, combined with later thermal treatment may represent a promising way for the synthesis of other transition metaloxide functional nanomaterial更多还原