【作者】 杨桂芹；

【导师】 刘平； 李朝晖；

【作者基本信息】 福州大学 ， 无机化学， 2005， 硕士

【摘要】 近年来,光催化氧化技术作为一种新兴的环境污染治理技术,以其反应条件温和,在室温下具有深度氧化能力,无二次污染,可直接利用太阳能,效率高,设备简单等诸多优点而受到各界的广泛关注,在环境保护领域取得了累累硕果。自从1985 年Matsunaga 报道了TiO₂的光催化杀菌后,光催化技术在杀菌方面的应用也已逐渐受到关注。结合本所对病毒的灭活研究,本文以牛血清白蛋白（BSA）和卵磷脂（PC）为目标物,研究了光催化剂对病毒的重要组成成分蛋白质和磷脂的降解反应过程。利用高效液相色谱（HPLC）、傅立叶变换红外光谱（FTIR）、紫外可见近红外光谱（UV-Vis-NIR）、时间分辨荧光光谱（FL/FS900）等手段对BSA 和PC 的降解过程中产物和中间体进行了检测,并在此基础上对其降解过程进行了推测,探讨了催化剂用量、焙烧温度、比表面积和表面电性与其光催化降解性能的关系。论文得到了如下的结论:（1）在本论文的实验条件下,400℃焙烧的TiO2 和365nm 紫外光共同作用5 小时内可以使BSA 完全分解,单纯365nm 的紫外光5小时内仅可以使BSA 部分分解,而单纯的TiO₂对BSA 仅有吸附作用,无法使之分解;（2）在TiO₂和365nm 紫外光共同作用下,40 小时内BSA 可完全被矿化成CO₂ 和无机离子;（3）催化剂的用量、焙烧温度以及反应条件对TiO₂ 的降解效率具有很大的影响;（4）催化剂表面电性通过影响其对BSA 的吸附对其降解效率具有一定的影响,当pH 值介于4.74（BSA 的等电点）和6.4（400℃焙烧的TiO2的等电点）之间时,BSA 的吸附量较大,而降解效率也较高;（5）利用TiO₂膜光催化降解PC,膜的制备方法、基底、反应气氛以及光源对PC 的降解效率有明显的影响。电泳法制备的TiO2 膜表现出良好的活性,O2 气氛下TiO2 膜活性较好,而在N₂气氛下几乎没有活性。虽然利用光催化灭活细菌在文献中已经有不少的报道,但是本论文首次系统地研究了光催化对于生物大分子的降解作用。这些结果对于我们深入了解光催化杀菌消毒的机理以及开发基于光催化理论的广谱的、高效的、环境友好的病毒灭活剂及其应用技术均具有一定的理论和实际意义。更多还原

【Abstract】 Semiconductor photocatalysis is a novel technology for the treatment of environmental pollutions in recent years. This new technology attracts much attention for its lots of advantages: complete oxidation of almost all organic pollutants, no secondary pollution and the direct utilization of solar energy. Ever since Matsunaga reported the bactericidal effect of TiO2 in 1985, attention has been paid to photocatalytic technology in the application of sterilization. In this study, bovine serum albumin （BSA） and phosphatidylcholine （PC） were selected as model compounds to study the photodegradation of two important components of virus, ie, protein and phosphatidycholine by the photocatalysts. High performance liquid chromatogram （HPLC）, Fourier-transform infrared spectra （FTIR）, ultraviolet visible spectra （UV-Vis）, time-resolved fluorescent spectra were used to monitor the photocatalytic processes. The effects of photocatalysts loading, calcinations temperature, specific surface areas and surface charge states on the photocatalytic efficiency were also investigated. The following results were obtained: （1） Under UV illumination, BSA could be completely degraded by TiO₂ in 5 h. However it could only be partly degraded under UV illumination and no degradation of BSA was observed on TiO₂ only; （2） BSA could be completely mineralized to CO₂ and inorganic comounds after 40 h photocatalytic treatment; （3） Photocatalysts loading, calcinations temperature and reaction acidity can significantly influence the photodegradation efficiency; （4） The surface charge states of the photocatalysts played an important role in the photodegradation process by influencing the adsorption of BSA on the surface of photocatalysts. At pH range between 4.74 （the isoelectric point of BSA） and 6.4 （the isoelectric point of TiO2 calcined at 400℃）, higher absorption of BSA on the photocatalyst surface was found and led to a higher photocatalytic efficiency; （5） The photocatalytic degradation of PC on TiO₂ film was significantly affected by the way the film was prepared, the substrates, the reaction atmosphere and the light source. Best activity was observed on the films prepared by electrophoresis. The photocatalytic activity was higher in the existence of O₂ compared to that in N₂. Although the bactericidal effect of photocatalysts has been well documented, to our knowledge this is the first time that the photocatalytic degradation of biomolecules was systematic investigated. Our results can be useful for a better understanding of the bactericidal mechanism of photocatalysis and in the developing of broad-spectrum, high effective and environmental friendly antivirus agents based on photocatalysis.更多还原