2.5. Photocatalytic activity of titanium dioxide coatings
The photocatalytic activity of TiO2 coatings was monitored by the
reaction of terephthalic acid (TA) oxidation. TA easily reacts with hydroxyl
radicals forming 2-hydroxyterephthalic acid (TAOH). This
product can be quantified by emission spectroscopy. The tested film
was placed in an aqueous solution of TA (3 mmol dm3
) in a quartz
cell (35 25 5 mm3
). 150 W XBO lamp equipped with the 10 cm
water filter and a 400 nm cut-off filter was used as a light source.
The average irradiance was 6.8 mW cm2
. Emission spectra of the
irradiated solution were recorded (LS 55, Perkin Elmer) in 1 cm
quartz cuvette applying excitation at 315 nm.