纳米TiO₂薄膜的制备及光催化降解甲醛气体的实验研究

【作者】 孙瑶毅；

【导师】 谢洪勇；

【作者基本信息】 大连理工大学 ， 化工过程机械， 2004， 硕士

【摘要】 近年来，人们将光催化技术用于去污、除臭及空气净化等方面做了广泛的研究。但TiO₂粉体难以实际应用，故如何制备高性能的TiO₂光催化活性膜是其应用化必须解决的关键问题。本论文用丙烷／空气火焰法制得的纳米TiO₂粉末水解成胶，浸涂石英基体上制备TiO₂光催化活性膜是一项极具应用前景的研究工作。 本论文介绍了纳米TiO₂光催化降解甲醛的机理；用液相沉积法在石英基片上制备出纳米TiO₂薄膜，利用分光光度计间接测量TiO₂薄膜厚度，研究了超声波震荡、胶体浓度、沉积时间及沉积次数对薄膜厚度的影响；借鉴气体吸附理论，初步建立了制备TiO₂薄膜的沉积动力学模型。 本论文建立了光催化连续管式反应器，通过光催化降解甲醛气体的实验来表征纳米TiO₂薄膜的光催化活性，实验研究了薄膜类型与膜厚对甲醛转化率的影响。通过建立管式反应器模型，计算了光催化反应速率常数，并与文献结果进行了比较。更多还原

【Abstract】 Much work has been done in recent years on the photocatalytic treatment of environmental pollutants found in the gas phase for possible application to decontamination, purification, and deodorization of atmospheres. Because TiO2 powder is hard to reclaim, how to prepare good films with high capability is important to the technical application. The TiO2 powder prepared by C3H8/Air CVD method is used to prepare TiO2 thin film using a damp method. This research has a good foreground.The mechanism of the photodegradation of formaldehyde is introduced. The TiO2 thin film on quartz glass is prepared by Liquid Phase Deposition(LPD) method. The thicknesses of the films are determined by a spectrophotometer. The influence factors on the thicknesses such as ultrasonic vibration, times of sedimentation, sedimentation time and concentration of TiO2 colloid are investigated. A mathematical model of sedimentation is set up on the basis of gas adsorption theory.A photocatalytic continual tub reactor is set up. The decomposition of formaldehyde photocatalyed by TiO2 is used as a standard test reaction for the evaluation of efficiency of the TiO2 thin film photocatalyst. The effect factors of degradation of formadehyde such as the style of thin films and the thicknesses are researched. A math model of tub reactor is established with one dimension level. The reaction constant is caculated and is compared with others’.更多还原