【作者】 邬剑波；

【导师】 马向阳； 杨德仁；

【作者基本信息】 浙江大学 ， 材料物理与化学， 2007， 硕士

【摘要】 纳米材料／纳米结构由于新颖的物理、化学和生物学特性以及在纳米器件中的潜在用途成为当今材料领域中十分重要的研究对象。水热法由于设备简单，成本低，可控性好，制备的材料纯度高、结晶好等优点，广泛用于纳米材料的制备。本文采用有机物辅助水热法合成了CuO纳米花、Co₃O₄纳米线、ZnO纳米荔枝，还合成了过渡族金属氧化物纳米片、纳米球。通过透射电镜（TEM）、场发射扫描电镜（FESEM）、X射线衍射（XRD）等手段对上述纳米材料／纳米结构进行了表征。本文的主要结果如下：1．提出N-N-二甲基甲酰胺辅助溶剂热法合成CuO空心花状纳米结构，并且探讨了相关的形成机理。以这种CuO空心花状纳米结构作为负极材料的锂离子电池的放电容量和循环寿命都优于以实心CuO纳米颗粒作为负极材料的锂离子电池。2．利用水热法先制备出一维碱式碳酸钴纳米结构，再利用后续热处理得到Co₃O₄纳米线。以Co₃O₄纳米线作为负极的锂离子电池首次放电容量达到1540mAhg^-1，经过10个充放电循环之后，放电容量稳定在1100 mAhg^-1。3．利用乙二醇辅助溶剂热法制备出荔枝状ZnO纳米结构，该结构是由直径在50nm左右，长度为几百纳米的ZnO纳米棒自组装形成的。荔枝状ZnO纳米结构由于具有很大的比表面积而在室温下对酒精和氨气有很高的灵敏度和快速的响应恢复。4．通过甲醛的还原作用结合水热法制备了金属氧化物（Fe₂O₃）纳米球。研究发现，由于甲醛的还原作用，Fe³⁺离子先被还原成非晶态Fe纳米球核心，通过水热过程中的长大和氧化形成Fe₂O₃纳米球。5．提出了一种普适的柠檬酸辅助水热制备六角晶系金属氧化物纳米片的方法。实验发现柠檬酸的鳌合作用限制了六方晶系晶体的C轴方向的生长，这是形成六角晶系金属氧化物纳米片的关键。更多还原

【Abstract】 Nanomaterials and nanostructures have attracted great interests due to their novel physical, chemical, and biological properties as well as the potential applications in nanodevices. Hydrothermal method has been widely employed to prepare nanomaterials and nanostructures due to its advantage of low synthesis temperature, simplicity, cost-effectiveness, high crystallization, environmental friendliness and high yield.In this thesis, organic molecules assisted hydrothermal methods are used to prepare CuO nanoflowers, Co₃O₄ nanowires, litchi-like ZnO nanostructures and transition metal oxides nanoplates （e.g. Fe₂O₃, Co（OH）₂ and Ni（OH）₂） and nanospheres （e.g. Fe₂O₃, Ni and Cu）. The samples synthesized are characterized by transmission electron microscopy （TEM）, field emission scanning electron microscopy （FESEM）, X-ray diffraction （XRD） and so on. The primary results achieved in the thesis are listed in the following.1. Hollow flower-like CuO nanostructures were synthesized by DMF-assisted solvothermal method. The formation mechanism of such nanostructures has been preliminary presented. The lithium battery using the Flower-like CuO nanostructures as the cathode exhibited higher capacity and better cycle life than that using the conventional CuO nanoparticles as the cathode.2. The Co₃O₄ nanorods were prepared by the calcination of the cobalt-hydroxide-carbonate nanorods which were synthesized by the formaldehyde-assisted hydrothermal method. The first cycle discharge capacity of the electrodes made from Co₃O₄ nanorods was about 1540 mAh/g, and maintains about 1100 mAh/g after ten cycles.3. A novel solvothermal process using ethylene glycol （EG） as solvent has been employed to synthesize the litchi-like ZnO nanostructures consisting of the numerous ZnO nanorods with the diameter of about 50 nm and the length of about several hundred nanometers. The litchi-like ZnO nanostructures based gassensor exhibited high sensitivity for ethanol and ammonia as well as quick response and recovery time when operating at room temperatures due to the high surface-to-volume ratio of litchi-like ZnO nanostructures.4. Fe₂O₃ nanospheres were synthesized by a hydrothermal process in which formaldehyde was used as the reducing agent. During the hydrothermal process, the amorphous metal Fe nanospheres with the diameters of 20 nm were firstly formed by the reduction of Fe³⁺ ions, subsequently, they were oxidized and further grew up into Fe₂O₃ nanospheres.5. A citric acid （CA）-assisted hydrothermal process was used to prepare Fe₂O₃ hexagonal nanoplates with a lateral size of about 100 nm. In addition, the hexagonal nanoplates of Co（OH）₂, MnCO₃, and Ni（OH）₂ were also synthesized by this route, indicative of the universality of the solution route presented herein. Furthermore, the mechanism for the formation of the platelike nanostructures has been preliminarily discussed. It is believed that the capping molecule of CA, which inhibits crystal growth along the <001> direction due to its chelating effect, plays a critical role in the hydrothermal formation of the nanoplates.更多还原