2.3. Photocatalytic reaction
The photocatalytic activity of the TiO2 films was examined for
the degradation of methylene blue over a period of 320 min.
The film was immersed in 50 ml of methylene blue solution
(8 mg/L). Before irradiation, the solution was kept in the dark
for 30 min to ensure adsorption equilibrium between the dye
and the photocatalyst [23]. The reactor was a laboratorybuilt
system comprising of a 300-W high-pressure mercury
UV tube emitting UV radiation with a peak wavelength of
365 nm. When different TiO2 films were tested for the photodegradation
of methylene blue, the distance between the light
source and film was kept constant to achieve a constant light
intensity on the film surface. The photo-degradation was monitored
by measuring the absorbance of the solution.