【作者】 张小细；

【导师】 李学良；

【作者基本信息】 合肥工业大学 ， 应用化学， 2006， 硕士

【摘要】 在查阅大量文献的基础上,总结了纳米材料的结构、性质、应用及制备技术的进展。本论文中,在水热和溶剂热的基础上,我们发展了几种纳米材料的控制合成技术,制备了海胆状及线状镍纳米晶体、空心块状及纤维状草酸镍纳米晶体、氧化镍棒束、花状β-氢氧化镍及花状氧化镍微晶。应用了XRD、TEM、SEM等测试方法对这些材料进行了物相和形貌表征。 论文主要内容如下:在水体系中用超声还原法制备了球形金属镍纳米微粒,粒径分布均匀。在乙二醇体系下用水合肼还原镍盐成功合成了海胆状和一维线状镍纳米晶体,并研究了不同溶剂对产物形貌产生的影响。研究了海胆状镍的磁学性质,发现海胆形镍纳米晶体比块体材料具有明显增强的矫顽力。在无水乙醇体系中制备出了空心块状和纤维状草酸镍前驱体,然后用水合肼还原纤维状草酸镍前驱体制备出了一维线状镍纳米晶体。 通过热分解棒状丁二酮肟镍前驱体制备出由纳米粒子组成的氧化镍棒束,热分解温度和时间对氧化镍棒的形貌影响很小,但随着温度的升高和时间延长,氧化镍粒子的粒径变大。氧化镍棒束的光学带隙(E_g)的值约为3.51eV。 发展了一种水热络合沉淀法在140℃下反应4小时成功合成了花状形貌β-氢氧化镍晶体,发现每个花是由许多纳米薄片组成。络合剂乙二胺(en)对产物形貌起着关键作用。并研究了反应温度和表面活性剂聚乙烯吡咯烷酮(PVP)对产物形貌影响。热解花状氢氧化镍前驱体成功合成了花状氧化镍晶体,分解产物氧化镍基本维持了前驱体氢氧化镍的形貌。并用合成的花状氧化镍粉末作为活性物质制作成氧化镍电极,循环伏安(CV)测试表明花状氧化镍粉末可以用来作超电容器电极材料。更多还原

【Abstract】 Based on detailed investigation of a great deal of related literature, the structure, property, application and synthetic method of nanomaterials have been reviewed. In this paper, on the basis of hydrothermal and solvothermal techniques, we developed several controllable synthetic techniques to fabricate urchin-like and wire-like nickel nanocrystalline, NiC₂O₄·2H₂O nanoboxes and nanofibres, NiO rods, flower-like β-Ni（0H）2 and flower-like NiO crystals. The crystallinities and morphologies of the products were characterized by XRD TEM, SEM, etc. The major contents can be summarized as follows:Metal nickel nanoparticles have been prepared by ultrasonic reduction in water. The prepared particles are spherical and their size is well-distributed. Urchin-like and wire-like nickel nanocrystallites have been synthesized by hydrazine reduction in ethylene glycol. The results reveal that solvent and reaction time play important roles in the morphology control of nickel nanocrytallites. The thus-prepared urchin-like nickel showed a much-enhanced coercivity than bulk nickel.NiC₂O₄ 2H₂O nanoboxes and nanofibres have been prepared by a solvothermal method in absolute ethanol. And we have synthesized wire-like nickel nanocrystals through the reduction of nickel oxalate nanofibres by hydrazine hydrate.NiO rods which consist of nanoparticles have been synthesized via thermal decomposition of rod-like nickel dimethylglyoximate precursor. The calcining time and temperature have less effect on the morphology of NiO rods. With increasing the calcining time and temperature, the size of particles became larger. The optical absorption band gap of the NiO nanoparticles was 3.51 eV.Flower-like /?-Ni（0H）2 crystals have been successfully prepared by a hydrothermal complexing-precipitation process at 140 °C for 4 h. Each flower is constructed with dozens of flakes, which are connected with each other. Ethylenediamine plays an important role on the flower-like morphology of the product. The influences of reaction temperature and surfactant （PVP） to β-Ni（OH）₂ morphology were also studied. Flower-like NiO nanocrystals have been synthesized by the thermal decomposition of Ni（OH）₂ precursor. Cyclic voltammogram（CV） shows flower-like NiO may be used as a good electrode material for supercapacitor.更多还原