Photocatalytic reaction kinetics model based on electrical double layer theoryⅡ. Infrared spectroscopic characterization of methylorange adsorption on TiO2 surface
(1. Guangzhou Institute of Energy Conversion,
The Chinese Academy of Sciences,Guangzhou 510070, China;
2. Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control,Guangdong Institute of Eco-Environment and Soil Science,
Guangzhou 510650, China;
3. Department of Applied Chemistry, South China University of Technology,
Guangzhou 510640, China)
The Chinese Academy of Sciences,Guangzhou 510070, China;
2. Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control,Guangdong Institute of Eco-Environment and Soil Science,
Guangzhou 510650, China;
3. Department of Applied Chemistry, South China University of Technology,
Guangzhou 510640, China)
Abstract: In the process of heterogeneous photo-catalytic degradation, the reaction rate depends strongly on the property of organic binding on the surface. It is important to identify the adsorption of organic compounds on TiO2 surface to understand the mechanism of degradation and proper kinetics expression. The infrared spectroscopy was used to analyze the methyl orange adsorption on TiO2 surface in aqueous solutions in different pH ranges. The variation of the surface complexation of methyl orange formed on the TiO2 surface in different acid and basic media was discussed. And the adsorption amounts were also qualitatively analyzed. Methyl orange has strong, weak and little adsorption on the TiO2 surface in acid, basic and near neutral solution, respectively.
Key words: infrared spectroscopy; adsorption; methyl orange; TiO2