【作者】 黄雪锋；

【导师】 桂和荣； 黄显怀；

【作者基本信息】 安徽理工大学 ， 环境工程， 2006， 硕士

【摘要】 TiO₂纳米材料具有良好的化学稳定性、抗磨损性、低成本、无毒等特点而成为最具有应用潜力的光催化剂。本文扼要介绍了TiO₂光催化材料的研究进展及应用前景,其中包括空气中有机物的光降解、微生物的杀灭、污染物废水的处理。并系统地阐述了TiO₂光催化反应机理,活性影响因素,改性种类以及各种制备方法。 本研究以钛酸四丁酯和氨水为前驱物,采用水热法制备了N掺杂TiO₂纳米微粒,催化剂颜色呈浅黄色。利用X射线衍射（XRD）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（UC-Vis DRS）等技术对不同条件下制备的产物进行了表征。探讨了不同体积比的前驱物、水热温度、水热时间、及煅烧温度对水热产物的影响;考察了所制备的N掺杂催化剂分别在紫外线和可见光下光催化降解甲基橙和苯酚的催化性能。 在研究TiO₂光催化反应动力学的实验中,采用商用TiO₂为催化剂,以直接耐酸大红4BS为模型污染物,研究光强与起始反应速率的关系,以及所遵守的动力学模型。研究发现,无论是在低光强（0.019mw/cm²）还是高光强（5.9mw/cm²）下,反应都是严格地遵循L-H零级动力学,即反应速率都为常数;研究还发现,在较低光强下,反应速率随光强的增大而逐渐增大,当超过3.08mw/cm²时,反应速率变化很小。从实验数据中可以预测到反应速率与光强的平方根有很好的线性关系,这也正好说明了高光强照射作用下只能大大降低量子效率。更多还原

【Abstract】 The titania（TiO₂） which has the properties of better steady of chemistry、 resisting erosion、 low cost、 nontoxicity etc is becoming the best potential appliance in the photocatalysts. The dissertation firstly introduced recent developments in titania photocatalysis and its application prospects for the treatment of organics and poisonous bacteria in the air or wastewater. Then the mechanism of titania photocatalytic process, influencing factors of photacataytic activity, classes of modification and various methods of preparation were systematically reviewed.In the research, nitrogen doped TiO₂ nanosize particles were prepared under hydrothermal condition with tetra-n-butyl titanate and ammonia as the precursors, the colour of this photocatalyst was yellowlish. The products obtained under different conditions were characterized by means of X-ray diffraction（XRD） 、 X-ray photoelectron spectroscopy（XPS） and ultraviolet-visible diffuse reflection spectrum（UV-Vis DRS）. The influences of various proportion by volume, hydrothermal temperature, hydrothermal time and calcination temperature to the structure and activities of catalysts were investigated. Photocatalytic activities of the nitrogen doped catalysts were evaluated under ultraviolet and visible light irradiation by photodegradation of methylic-orange and phenol respectively.In order to research the kinetics of TiO₂ photocatalysis, choosing the TiO₂ on sale as the catalyst, and using the direct fast scarlet（4BS） as the model pollutant. The dependence of initial degradation rates on the incident light intensity and kinetic model were discussed. The results showed that neither in high nor low light intensity, in all cases 4BS degradation models seriously observed the L-H zero kinetics, that was to say the initial rates were constants. It was also found that, in the case of lower light intensity, the higher light intensity the quicker rate, when it exceeded 3.08mw/cm², the change of degradation rate was little. To account for the experimental finding, the rates are linearly proportional to the square root of the intensity in a large range, it is also proved that the high light intensity irradiation will decrease the quantum yield.更多还原