环境工程毕业论文--改性纳米TiO2光催化降解甲基橙的研究.doc

摘 要 当今全球范围内都不同程度地出现了环境污染问题, 探索和研究经济有效的消除环境污染物的新技术和新方法具有重要的意义。二氧化钛光催化作为一种先进的氧化技术,在环境领域具有十分广阔的应用前景。然而，TiO2光催化剂有其自身的缺陷：量子产率低和太阳能利用率低。 研究表明，在TiO2中掺杂金属离子，不仅能影响电子--空穴对的复合率，提高表面羟基位，改善光催化效率，还可能使TiO2的吸收波长范围扩大到可见光区域，增加对太阳能的转化和利用。但金属沉积量过大会使TiO2光催化性能下降。此外，超声可以有效改善粒子的结构，提高其光催化性能。本文针对不同金属（Ho、Gd、Zr、Ag）的不同含量（0.5%、1%、2%、3%、4%）进行掺杂改性超声制备，研究其对TiO2的光催化活性的改变。 首先,本文将概述TiO2的制备方法,光催化氧化的机理及应用,并且通过国内外对TiO2研究进展,阐述研究金属掺杂改性、超声浸渍制备TiO2的原因。 其次,本文将详细介绍制备纯TiO2和金属掺杂改性TiO2的超声制备溶胶－凝胶法。 再次，通过紫外光下样品的降解甲基橙实验，研究其光催化性能。 研究结果表明：溶胶－凝胶法成功制备TiO2，金属掺杂改性可以提高其光催化活性，并初步判断所选取金属元素的合适掺杂量。 关键词：TiO2,光催化活性,溶胶-凝胶，金属掺杂，超声 Abstract Nowadays,various degree of the problems of environmental pollution have been presenting in the global range. In order to eliminate environmental pollutants , it has significant meanings that effectively new technology methods are explored and studied Therefore, as an advanced photocatalysis technique, TiO2 photocatalysis technique has an extremely wide application prospect in the domain of environment. However, TiO2 has its own shortcomings : low quantum yield and low utilization of solar energy. Research shows that the TiO2-doped metal ions, can not only affect the electronic -- hole on the composite rate, improve surface hydroxyl groups and photocatalytic efficiency, but also result in the absorption wavelength range extended to the visible region and the increase of solar energy conversion and utilization. However excessive metal deposition will affect TiO2 photocatalytic properties. Moreover, ultrasound can effectively improve the particle structure and enhance its photocatalytic properties. We study on TiO2 ,which is made by ultrasound ,photocatalytic activity changes on different metals (Ho, Gd, Zr, Ag) of different content (0.5%,1%,2%,3%.4%). First of all, this paper would summarize the making method of TiO2,the mechanism and the application of photocatalytic oxidation. Then it expounded the reason that researching metal-doped TiO2 made by ultrasound through the relative study internal