화학공학소재연구정보센터
Applied Catalysis A: General, Vol.226, No.1-2, 199-211, 2002
Enhancement of the photocatalytic activity of TiO2 film via surface modification of the substrate
A new type of TiO2 film is prepared by insertion of a bifunctional silane agent bearing sulfonate group in between TiO2 and the substrate. The alkoxyl silane is bound to the surface of the substrate via molecular self-absorption and the terminal sulfonate group is used to grasp the TiO2 particles to form stable film. Modifications of the TiO2 catalysts, such as metal deposition and calcination, were carried out simply with the films on substrates. The activity of this new type TiO2 film is tested by catalytic photodegrading of salicylic acid in water. It was found that when the particle size of the TiO2 is smaller than 200 nm, the catalytic activities of the TiO2 films deposited on sulfonate-grafted glass are better than those of the films deposited on unmodified glass. Increasing the crystallinity of TiO2 particles, depositing the precious metals (such as Au or Pd) on TiO2, or aging the TiO2 film will enhance the catalytic activity of TiO2. The enhancement is better for the film deposited on sulfonate-grafted substrates. In spite of calcining the TiO2 film decreased its catalytic activity due to the particle aggregation, the decrease is also less significant for TiO2 films deposited on sulfonate-grafted substrates. The sulfonate group can be regarded as a dispersion agent for TiO2 film deposition and calcination.