【作者】 李瑛；

【导师】 钟家柽；

【作者基本信息】 武汉大学 ， 无机化学， 2005， 硕士

【摘要】 本文简要介绍了纳米TiO₂半导体催化剂的制备及其在环保领域方面应用研究的最新进展及国内外研究现状,并主要进行了纳米TiO₂薄膜催化剂的制备及气相光催化氧化苯胺的研究,同时也初步探讨了气相光催化氧化苯胺的反应机理。 本文中采用两种不同方法制备了纳米TiO₂薄膜催化剂,第一种是采用胶粘法,以水玻璃为粘贴剂,稀硫酸溶液为固化剂,在玻璃纤维布上制备了纳米TiO₂薄膜;第二种是不使用粘贴剂、固化剂,直接利用非晶态纳米TiO₂胶体,在玻璃纤维布上制备了纳米TiO₂薄膜。用扫描电子显微镜（SEM）、比表面及孔径分析（BJH）观察了两种薄膜的表面形貌和结构特征。用纳米TiO₂薄膜作催化剂,进行了光催化氧化低浓度的气态苯胺的研究,考察了光源、催化剂浓度、苯胺的初始浓度及水蒸气等因素对气态苯胺降解率的影响。实验结果表明:当TiO₂含量在5%时,紫外杀菌灯光照7h后苯胺的降解率最高,达到84.7%;若在通入水蒸气的条件下,苯胺的降解率更高,可达到94%。此外,对所制备的两种不同薄膜的光催化活性进行了比较,直接利用非晶态纳米TiO₂胶体制备的纳米TiO₂薄膜的催化活性比使用粘贴剂、固化剂制备的纳米TiO₂薄膜更高。催化剂在使用一次后反应中的一些中间产物被强烈地吸附在催化剂的表面导致活性降低,但光照一段时间便可使催化剂活性恢复。 另外,本文采用傅立叶变换红外光谱法（FT-IR）、核磁共振氢谱（H¹-NMR）法、高效液相色谱（HPLC）法分析了苯胺在气相光催化氧化反应过程中出现的中间产物,并对气相光催化氧化苯胺的反应机理进行了初步探讨与推测。更多还原

【Abstract】 The paper has reviewed the most recent progress on the research of nanometer semiconductor catalysts. The current development of nano-TiO₂ photocatalyst has been considered including the preparation of catalyst and the application in degrading aniline. In this thesis, we mainly focus on the study of the gas-phase photocatalytic oxidation of aniline with nanometer TiO₂ thin film and the photocatalytic oxidation mechanism of aniline with the TiO₂ thin film is briefly discussed.The gas-phase photocatalytic oxidation of aniline on a new kind of nano-TiO₂ thin film was investigated. The photocatalytic thin film was prepared on the glass fibre cloth with two methods. The first method was the water glass as binders and dilute H2SO4 solution as solidifying reagent, and then nano-TiO₂ was loaded on the glass fibre cloth. Another method was that nano-TiO₂ crystal was directly loaded on the glass fibre cloth making use of non-crystal nano-TiO₂ colloid without binders and solidifying reagent. The nano-TiO₂ thin film’s surface characters were observed by scanning electron micrograph （SEM）. The photocatalytic degradation of gaseous aniline on the nano-TiO₂ thin film was carried out in UV illumination. Some important factors affecting the photocatalytic degradation were also studied such as the source of lamp, the concentration of TiO₂, the initial concentration of aniline, and water vapour existing. The experimental results indicated that the degradation rate of aniline reached 84.7% with 5% TiO₂ after UV-irradiation for 7h. If we added water vapour, the higher degradation rate of aniline would reach 94%. Furthermore, the photocatalytic activity with the nano-TiO₂ thin film prepared by the second method was higher than that by the first method. The partial intermediate products were absorbed on TiO₂ surface, which resulted in catalyst deactivation. But when it was irradiated under UV-illumination or solar irradation for some time, the catalyst could be reused without the loss of catalytic activity.In addition, the intermediate products of Photocatalytic oxidation of aniline were detected by Fourier transform infrared spectroscopy （FT-IR）、 Hydrogen¹ nuclearmagnetic resonance （tf-NMR）, and High performance liquid chromatography （HPLC） . According to these detected intermediate products, we briefly presumed the photocatalytic oxidation mechanism of aniline with nanometer TiC>2 thin film.更多还原