The development of immobilized visible light-active photocatalysts has attracted growing scientific interest due to numerous potential commercial applications. In this work sonicated and unsonicated sols were used for the development of thin films on glass substrates. The coatings were prepared using Fe2O3-TiO2 sols containing 1-5 mol% Fe2O3 and 99-95 mol% TiO2. The coatings were obtained by dip-coating method and annealed at 500 °C for 1 hour. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-Vis spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The ultrasound treatment of sols led to the reduction of the size of iron doped nanocrystals of TiO2 and absorption enhancement in the visible light.