溶胶凝胶法制备纳米TiO2薄膜及其性能的研究

Preparations and Photocatalytic Activity of Nano-TiO_2 Films

目的制备纳米TiO2薄膜并研究涂膜层数与催化性能的关系．方法采用溶胶凝胶法并利用提拉技术制备纳米TiO2薄膜．应用朗伯-比尔定律分析其光催化活性，利用金相显微镜观察单层和多层薄膜的表面形貌，用红外光谱和XRD分析所制备薄膜材料的结构，利用甲基橙溶液研究该薄膜的光催化性能．结果溶胶凝胶法在500℃的热处理温度制备了结晶良好的锐钛矿相结构的纳米TiO2薄膜材料，晶粒尺寸为40～80nm；控制提拉速度和加入乙酰丙酮，能使薄膜的缺陷减少；涂膜层数为5层时光催化性能比1层到4层时好，这是由于5层时薄膜表面更均匀、更致密，但是层数增加也使薄膜的内应力增加，致使表面产生裂纹．结论涂膜层数增加均使TiO2光催化性能得到提高，镀膜层数较少时，膜层较好，5层镀膜时膜层产生了裂纹．

TiO2 sol was prepared by sol - gel method. The nano - TiO2 film was plated on the surface of quartz glass by Czochralski technique. Then it was sintered at 500℃. The photocatalytic activity of the films was analyzed by Lambert - Beer＇s law. The morphology, crystal structure and stable crystal phase of TiO2 films were confirmed by Metallography Microscope and X - ray Diffraction measurement and PTIR spectroscopy. The results showed that the nano - TiO2 was anatase and the size of the grain was 40 - 80nm; the thickness of the films and the ageing time had an important effect on the photocatalytic activity of the films; the thicker is the film, the greater is the photocatalytic activity of the films ; the layers of the nano - TiO2 film were less, the film was more ideal. There was crack when the layers of the film were more than five.