Photosensitization of titanium dioxide with 4′-dimethylaminoflavonol

The paper focuses on spectral properties of 4′-dimethylaminoflavonol (DMAF) in the presence of colloidal titanium dioxide (q-TiO2). The influence of q-TiO2 on absorption and fluorescence properties of DMAF (spectral changes, fluorescence quenching, increase of the fluorescence lifetimes) confirms the photosensitization effect, observed also as visible light induced photocurrents. Interestingly, an efficient photosensitization of titanium dioxide was observed also in TiO2-based systems with the surface modified with hydrophobic silyl groups or fluoride anions. Quenching of fluorescence of DMAF and DMAF@TiO2 by oxygen points at the generation of reactive oxygen species, indispensable in the process of organic pollutants degradation.