• Baudys, Michal
• Rusek, Jakub
• Paz, Yaron
• Paušová, Šárka
• Krýsa, Josef

Abstract

Modifying a hydrophilic TiO2 photocatalyst by hydrophobic rare-earth oxides (REOs) maypromote affinity to hydrophobic non-polar species, thus improving photocatalytic activity. Thepresent work was focused on the kinetics of photocatalytic degradation of the polar AcidOrange 7 (AO7) and of the non-polar herbicide monuron (3-(4-chlorophenyl)-1, 1-dimethylurea) and its degradation intermediates in the presence of composite TiO2 filmscontaining SiO2 binder and different REOs (CeO2, La2O3, Er2O3, Yb2O3). The addition ofREOs particles into the TiO2/SiO2 composite matrix resulted in an increase in the initialdegradation rate of monuron from 2.1 nmol min−1 cm−2 to 2.7 - 3.0 nmol min−1 cm−2.Furthermore, the ratios between the initial degradation rates of monuron to those of AO7 weresignificantly higher for composite films containing REOs showing a positive effect on theremoval of the non-polar monuron molecules for all REOs. A comparison between the kineticswith the various types of photocatalysts reveals that the positive impact of SiO2 and that ofSiO2/REOs on the kinetics was not limited to the conversion of monuron, but to the overallmineralization. The main novelty represents the fact although the rate of TOC decrease variedamong photocatalysts, the kinetics of intermediates is not significantly influenced

Topics

• impedance spectroscopy
• composite