TiO_2光催化薄膜的制备及其性能研究
文献类型：学位论文
| 作者 | 曾贤成 |
| 学位类别 | 硕士 |
| 答辩日期 | 2002 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 侯立松 |
| 关键词 | TiO<,2>薄膜 光催化活性 溶胶-凝胶法 掺杂 |
| 其他题名 | Preparation -characterization and photocatalytic properties of TiO2 films |
| 中文摘要 | 目前,制备具有光催化性能的材料是各国材料科学家们致力研究的一个重要方面,纳米二氧化钛具有根高的化学活性,具有极强的光催化特性等优点,倍受青睐.溶胶-凝胶法是制备功能薄膜和涂层、块体、纤维、粉体以及复合材料等在内的多种形式材料的一种方法.合成材料的结构与性质和溶胶-凝胶法合成材料的化学与物理过程的诸多因素有关.这些因素包括:化学反应前驱体的种类和性质、溶剂的性质、化学反应体系的酸碱度、添加剂的特性与浓度、反应温度以及由溶胶向凝胶转化,最后形成材料的热历史等.该论文还研究了掺杂少量(≤1mol.%)铁离子、铬离子对TiO<,2>薄膜的光催化性能的影响,发现掺杂铁离子和铬离子对TiO<,2>薄膜光催化性能有明显的增强作用,它们的最佳掺杂浓度都是0.5mol.%.而且发现Fe<'3+>搀杂比Cr<'3+>离子掺杂效果明显.另外,我们又做了掺杂镉离子的TiO<,2>薄膜光催化性能的研究,发现掺杂量为10mol.%CdO的TiO<,2>薄膜具有较高的光催化活性. |
| 英文摘要 | Nowadays, preparation of nanoscale photocatalystic materials is one of the attractive topics to which scientists have been paying great attention and extensive research. Among the others, nanoscale TiO2 films have been intensively investigated due to its high photocatalystic activity. Sol-gel process is an effective chemical method for the synthesis of nanometer particles and functional materials, such as coating, fiber, powder and composite materials, doped with various kinds of functional groups. The structure and properties of the synthesized materials depend on the parameters of the sol-gel reaction system. These parameters include the type and nature of the adopted precursors and the selected solvents and additives, the temperature and pH value of the sol-gel system as well as the heat treatment history of the gel product. In this study, TiO2 thin films were prepared using the sol-gel method and spin-coating technique, and characterized by means of XRD, DTA-TGA, TEM, SEM etc. The photocatalytic performance of these films were studied by measuring the photodecomposition of Rhodamine B and benzene on the surface of the T1O2 films and improved by introducing additives such as chromium, iron, and cadmium ions. In order to obtain TiO2 thin films of high quality, it is necessary to prepare homogeneous and stable sols having suitable viscosity for spin-coating. For this purpose, a systematic investigation was carried out to make clear the effect of the reaction parameters on the viscosity of the system, especially the pH (acid catalysis or base catalysis), the addition of acetylacetone (AcAc), the addition of cadmium acetate and AgNO3. Our experimental results show that in the Ti (OC4H9_4-C2H5OH-H2O system, the gelling time decreases with increasing pH value under the condition of acid catalysis, whereas increases with increasing pH value under the condition of base acid. The introduction of AcAc into the system under a slightly acidic condition (pH=6.36) could greatly improve the stability of the sol, for example, the gelling time of the sol with the [AcAc]/[Ti(OC4H9)4] ratio being 0.3 is lOOh, while it becomes 1200h when the ratio was 0.5. Moreover, the introduction of AgNO3([AgNO3]/[Ti]=l:10) could also greatly stabilize the sol systems, either under the acidic condition(pH=4.33) or under the basic condition(pH=8.36), so that the gelling time could also be prolonged up to 700h. On the basis of the above results, the viscosity of the sol systems has been effectively adjusted and controlled in the suitable rage for spin-coating, and high quality TiO2 thin films have been obtained under the following optimized experimented parameters: [H2O]/[Ti]=2:l, [C2H5OH]/[Ti]=4:l, [AcAc]/[Ti]=2:10, [AgNO3]/[Ti]=l:10 at pH=2.6. After heat treatment at 625 °Cfor 1.5h, the particle size in the TiO2 films is less than 50nm. Our studies on the effect of certain dopants on the photocatalytic performance of the TiO2 thin films show that the addition of a small amount 1 mol.%) of iron or chromium ions can significantly improve the photocatalytic performance of the TiO2 films, though the iron ions were better than chromium ions. The optimum concentration of both iron and chromium ions are 0.5mol.%. On the other hand, the addition of cadmium ions at higher concentration can also greatly improve the photocatalytic performance. The optimum composition of the films is 10 CdO-90 (mole ratio). |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16485]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 曾贤成. TiO_2光催化薄膜的制备及其性能研究[D]. 中国科学院上海光学精密机械研究所. 2002. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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