Composite TiO2/ZnO films were prepared targeting novel materials with improved photocatalytic and optical properties. The films were synthesized via sol-gel technique using Ti alkoxide and Zn acetate as metal precursors and dip coating deposition on quartz substrate.
The optical characteristics were assessed via measurements of UV-vis spectra of the films and via modeling of their complex refractive index in the frames of popular dispersion models (Forouhi-Bloomer (FB) and Tauc-Lorentz (TL). The photocatalytic properties of the films were investigated by monitoring their photoinduced hydrophilicity and NOx oxidation activity under UV irradiation. Modelling of the films’ optical constant via FB and TL models allowed determination of their energy band gap and thickness. The recorded blue shift of the absorption edge of composite films Ti25 and Ti50 was attributed to Burstein-Moss effect concerning heavy doped semiconductors. Under UV illumination, the hydrophilicity of all the films gradually increased with the change for the ZnO containing films to be more prominent. The pure TiO2 film exhibited the highest photocatalytic activity especially in NO to NO2 oxidation.