【作者】 杨刚；

【导师】 徐瑞芬； 袁方利；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 近些年来,纳米材料以其特殊的结构和在光、电、磁、化学等方面优异的性能吸引了越来越多研究者的目光。特别的,纳米二氧化钛材料已经被广泛应用于许多领域当中,包括化学工业、电子工业、环境保护、化妆品工业以及医药科学等等。为了改进二氧化钛材料的性能,包括纳米颗粒、纳米管、纳米棒、纳米球等多种形貌已经研制成功。空心结构材料作为一种新型材料,具有很多实心材料所不具备的优势,例如：高比表面积、低密度、优异的传输渗透性、强烈的光捕捉能力等。因此,空心结构金属氧化物材料的制备已经成为了广大材料科研人员新的课题。目前为止,虽然,采用不同方法已经制备出了许多类型的二氧化钛空心球材料,但是存在工艺流程复杂、产品质量有待提高等问题。本论文利用水热法开展了纳米级多孔TiO2空心球材料的制备,并对其结构、形貌、性能进行了表征和研究。主要工作如下：1、利用钛酸四丁酯作为前驱体,经水解后,在乙醇为溶剂热反应介质、碳酸氢铵为结构辅助剂的条件下,成功合成了纳米TiO2多孔空心球,并利用SEM、TEM、XDR和BET等材料分析方法对产物进行了表征。结果表明,所得产物为锐钛矿型二氧化钛,球径和壁厚分别约为100mm、20nm,形貌均匀,分散性较好。2、系统研究了反应时间、反应温度和不同结构辅助剂等参数对产物的影响,提出了气泡模板辅助的Ostwald熟化法制备空心结构的形成机理。该合成方法实验过程简单,无需去除模板,且无环境污染,是一种相对简捷环保的途径。3、对产物的光学特性、光催化活性、吸附性以及气敏性等进行了基础性能研究,以期在相关领域得到充分的利用。研究表明,Ti02空心球样品对有机染料具有极强的吸附性,并可以敏锐的感应到甲醛气体,具有良好的气敏性能。更多还原

【Abstract】 In recent decades, nanostructured materials have attracted much attention due to their special structure and excellent properties in optics, electrics, magnetics, chemistry, etc. Particularly, nanostructured titanium dioxide (TiO2) has been applied widely in many fields, such as chemical industry, electronic industry, environmental protection, cosmetics industry, medical science and so on. In order to improve the materials performance, nanostructured TiO2 with various morphologies, including particles, tubes, rods and spheres, has been investigated and fabricated successfully. Hollow structure material, as a newfashioned kind of materials, exhibits broad application prospect, because of its higher specific surface area, lower density, greater delivering ability, better permeation and stronger light-harvesting capacity compared to solid ones. Accordingly, the synthesis of hollow structure metal oxide has been the researchers’new subject. Up to now, many kinds of TiO2 hollow spheres were fabricated by different methods. However, there are still some problems in the technological process and product quality. In this paper, nano TiO2 hollow spheres material was prepared through a hydrothermal method, and the structure, morphology, properties of the products were characterized and researched. The main tasks are as follows:1. Nano TiO2 hollow spheres were obtained successfully in the ethanol solvothermal medium using tetrabutyl titanate and ammonium bicarbonate as reactants. XRD, SEM, TEM and BET were employed to characterize the as-synthesized TiO2 hollow spheres. The results showed that the products are anatase phase and has uniform morphology and good dispersion with average diameter of 100 nm and shell thickness of 20 nm.2. The effect of reaction time, temperature, and assistant agent on the phase and structure of the product were studied. A bubble-assist Ostwald ripening mechanism was proposed to explain the formation mechanism of porous TiO2 hollow spheres. This approach employs bubbles generated in situ as template combined with Ostwald ripening process, which is considered as a green and simple route to prepare hollow spheres.3. The optical property, photocatalysis activity, adsorbability and gas sensitivity of the products were researched, expecting to apply them in related fields. The results showed that the TiO2 hollow sphere samples exhibit very intense adsorption for organic dyestuff, and have a good behavior in gas sensitivity for methanal.更多还原