文档介绍：纳米二氧化钛粉体制备工艺及其性能研究
摘要
纳米二氧化钛因为其高效、无毒、稳定、成本较低等优点,在半导体材料中脱颖而出,成为应用最广的光催化剂,被广泛用于废水废气处理、光催化制氢、光电池、抗菌等领域,带来巨大的环境、社会、经济效益。
结晶二氧化钛有三种改性晶相分别为金红石型(四方,P42/mnm),锐钛矿型(四方,I41/amd)和板钛矿型(斜方晶系,Pcab)。锐钛矿型二氧化钛具有良好的光催化活性,作为催化剂被广泛的应用于各种各样的有机和无机污染物的降解。二氧化钛的合成已经建立了许多方法,比如溶胶―凝胶技术、水热合成法、化学气相沉积法、直接氧化法等等。其中,溶胶―凝胶法是最常用的方法,是因为它在较低的反应温度下具有获得独特的亚稳结构的可能性和良好的化学均匀性。
本文以钛酸丁酯为先驱物,乙醇为溶剂,醋酸为螯合剂,采用溶胶-,水浴时间,溶液的PH值,煅烧时间的影响。并结合纳米二氧化钛样品X射线衍射和扫描电镜表征的结果,找出制备二氧化钛的最优配比和最佳条件。
关键词: 溶胶-凝胶法;纳米二氧化钛;结晶度;晶粒尺寸;表面形貌
Nano titanium dioxide powder preparation technology and its performance study
Abstract
Nanocrystalline titanium dioxide (TiO2), regarded as the best photocatalyst for its high efficiency, nontoxity, biological and chemical stability, and low cost, has been widely used in many fields such as degradation of environment pollutants, water-splittingfor hydrogen production, antibacteria, dye-sensitized solar cells, et al. and has also brought people huge economic, social and environmental benefits.
Crystalline titania has three modification phases which are rutile (tetragonal, P42 /mnm), anatase (tetragonal, I41/amd) and brookite (orthorhombic, Pcab).Anatase-type TiO2 has excellent photocatalytic activity and widely used as catalysts for position of a wide variety anic and anic pollutants. Many methods have been established for titania synthesis such as sol-gel technique, hydrothermal method , chemical vapor deposition, direct oxidation and others. Among them, the sol-gel technique is one of the most used methods due to its possibility of deriving unique metastable structure at low reaction temperatures and excellent chemical homogeinity.
This paper discusses preparation of nanometer-sized titanium dioxide by Sol-Gel method. In the Sol-Gel process, Ti(OC4H9)4 is used as precursor, C2H5OH is used as solvent and CH3COOH is used as chelating agent. By the experiment, four factors and their effects are studied, namely, water bath temperature,water bath time, PH value of solutions and