Notes on heterogeneous photocatalysis with the model azo dye acid orange 7 on TiO2

作者:Baudys Michal; Zlamal Martin; Krysa Josef*; Jirkovsky Jaromir; Kluson Petr
来源:Reaction Kinetics, Mechanisms and Catalysis, 2012, 106(2): 297-311.
DOI:10.1007/s11144-012-0438-0

摘要

Photocatalytic activities of a series of well available commercial TiO2 powders in both suspended and immobilized forms were determined by kinetic measurements of the degradation of acid orange 7 as model compound. Although the powders showed lower photoactivity in the immobilized than suspended form, the differences among particular materials considerably varied. The porosity of the photocatalysts and related adsorption/desorption phenomena strongly influence the photocatalytic degradations occurring in aqueous suspension. The adsorption of the azo dye has a significant effect on observed concentration changes during irradiation and must be taken in account in the evaluation of degradation rates in suspensions. No direct correlation between photocatalyst material properties and photoactivity was found. The paper brings a convincing discussion that, with only minor exceptions, it is not possible to form any general conclusions on the performance of a standard type photocatalyst, even if a model reactant is used.

  • 出版日期2012-8