摘要
提出用粉末—溶胶法制备TiO2 薄膜型光催化剂 ,介绍了粉溶法的制备工艺及改变 pH值对催化活性的影响。研究结果表明 ,利用粉溶法或添加浓HNO3后制备的TiO2 薄膜光催化剂表现出了较高的光催化活性。结合结构表征详细分析了其中的原因。认为粉溶法制备的催化剂表面更粗糙 ,比表面积增大 ,膜厚度减小 ,这些都可能是其催化活性提高的原因。而加酸后膜催化活性提高主要是因为酸性条件下表面几乎没有Ti3+表面态 ,利于光生电子与光生空穴的分离。
The paper describes the preparation of the TiO 2 thin film photocatalyst by power-sol method. The photocatalytic activity of the catalyst was evaluated by measuring the decomposition of gaseous acetone under weak UV light illumination. The result showed that the photocatalytic activity was remarkably enhanced by the addition of the TiO 2 powder in the TiO 2 film. And the weight of the PS-TiO 2 film is 5 times less than that of the SG-TiO 2 film system. According to the SEM pictures, the reason maybe as that: The film via power-sol (PS-TiO 2 film) is more coarse than the film via sol-gel(SG-TiO 2 film), so the surface area is big and it is good for the photoefficent of UV light and reaction rate. Furthermore, adding TiO 2 powders into the starting solution induces much defect on the film and this is also benefit for the reaction rate. Last, the SG- TiO 2 film is so thick that it maybe has exceeded the best thickness of the film. Moreover, adding acid into the film can improve the photoreactivity of the film. Because acid can prevent the producing of Ti 3+ and it is benefit for the separation of photoelectron and photohole. Furthermore, decreasing the amount of Ti 3+ can increase the amount of O 2 -. O 2 - is also good for the photoreactivity of the film.
