【作者】 肖君佳；

【导师】 陈标华；

【作者基本信息】 北京化工大学 ， 化学工程与技术， 2011， 硕士

【摘要】 纳米氧化镍在电学、磁学和催化学方面有独特的性质,广泛应用于催化领域、燃料电池领域、磁性材料领域和气体传感器领域,是一种很有应用前景的功能性无机材料。氧化镍纳米材料的合成及其形貌结构与性能之间的关系是氧化镍纳米材料研究的两个主要方面,制备性能良好的氧化镍纳米材料并弄清其形貌结构与性能之间的关系对氧化镍纳米材料的进一步发展有极其重要的理论和实际意义。本文围绕纳米氧化镍的制备和性能研究,开发出两种乙二醇体系和乙醇-油胺体系制备氧化镍纳米材料的新方法,成功制备了纳米氧化镍微球和纳米氧化镍片体材料,并重点考察了表面形貌对材料性能的影响。本文发展了一种在乙二醇溶剂体系中合成制备纳米氧化镍花状微球的新方法。制备出的纳米氧化镍花状微球具有尺寸大小均匀,分散度良好,比表面积大和多孔径分布的特点。通过改变原料的浓度和pH值可实现对纳米氧化镍花状微球的形貌和表面结构进行调控,得到了三种形貌尺寸均一、表面结构不同、比表面积分别为59.9 m2 g-1、50.2 m2 g-1和15.1 m2 g-1的纳米花状微球。并在此基础上采用CO催化氧化反应为模型反应着重考察了花状表面形貌对催化性能的影响。与传统纳米氧化镍颗粒相比,该法制备的纳米氧化镍花状微球具有更好的催化活性,说明其花状的表面形貌和其多孔分布的特点有利于提高其催化性能；不同的纳米氧化镍花状微球,其催化性能随着比表面积的增大有提高的趋势。在上述工作基础上,开发了一种基于乙醇-油胺体系合成氧化镍纳米空心微球和片体的新方法。水的加入能引导前驱体氢氧化镍的晶相和形貌转变,从而实现对氧化镍纳米花状材料和片状材料的可控制备。在不加水的情况下得到为α-Ni(OH)2纳米空心微球,在体系中引入少量的水,可得到β-Ni(OH)2纳米片。这种形貌结构土的转变主要由α-Ni(OH)2和β-Ni(OH)2晶体结构上的差异引起。相比乙二醇体系制备的氧化镍纳米实心花状微球,该法制备的为空心微球,具有更大的比表面积(100.2m2/g)。纳米氧化镍空心微球的催化CO氧化性能优于纳米氧化镍片体,说明其花状空心结构具有较好的催化活性。氧化镍是一种重要的电极材料,本文对其电化学性能进行了初步的考察,发现纳米氧化镍空心微球比氧化镍纳米片具有更好的的电化学性能。更多还原

【Abstract】 Nano oxidation nickel is a kind of very promising functional inorganic materials, widely used in catalysis、fuel battery domin、magnetic materials and gas sensors because of its unique properties in electrical、magnetic and catalytic chemistry aspects. To preparation nickel oxide nanomaterials having the good performance and to make clear the relationship between the morphology structure and properties having the important theory and practical significance to the further development of the nickel oxide nanomaterials. In this paper we developed two new methods of preparation nickel oxide nanomaterials, obtained nano oxidation nickel microspheres and nanosheets in glycol system and ethanol-oil amine system, and emphasized investigate the surface morphology on the materials properties.This experimental work developed a new method to synthesis flower-like nanometer oxidation nickel microspheres,which have the features of uniform size、good dispersion、high specific surface area and much pore size distribution, in glycol solvent system. Emphasized the regulation of the surface morphology, and the influence on the performance of the surface morphology. Three kinds of oxidation nickel flower-like nanospheres with uniform size and different surface morphology can be obtained by chaging the concentration of raw material and the pH of solution. Their special surface area were 59.9m2/g、50.2m2/g and 15.1m2/g, respectively. The result of CO oxidation reaction show that the catalytic activity of flower-like nano oxidation nickel microspheres is better than that of traditional oxidation nickel nanoparticles for its novel morphology structure、high specific surface and much pore size distribution. For different flower-like microspheres, the catalytic activity have the trend to improve with the increase of the specific surface area.Another method to synthesis empty oxidation nickel nanospheres and nanosheets in oil amine system was developed on the basis of above work. We found water plays a very mportant role in this synthetic process. The empty oxidation nickel nanospheres, whose precursor is a-Ni(OH)2, were obtained without adding water, and the oxidation nickel nanosheets, whose precursor isβ-Ni(OH)2, were obtained wlile adding water. Compared withβ-Ni(OH)2 crystal,α-Ni(OH)2 has worse ordered degree、higher lamellar spacing and adsorption more water and organic molecules. Compared with the previous method, the empty nanospheres synthesized in this method has higher specific surface, which could reach 100.2 m2/g. The empty nanospheres have better catalytic properties and electrochemical properties, because them have higher specific surface area than the nanosheets.更多还原