A self-cleaning solution was introduced in this paper based on sol–gel and was applied for preparing self-cleaning TiO 2 . Fe 3+ ions have been doped into the TiO 2 crystal lattice. XRD analysis indicated that the obtained TiO 2 powder contains mainly the anatase phase and TiO 2 powder has a crystallite size distribution of 10–12nm. SEM micrographs have also confirmed nanometric distribution of the obtained powder. A series of uniform and transparent TiO 2 and Fe/TiO 2 films were prepared by cold spray technique which may result in high uniformity in the final coated surfaces. Photocatalytic activity of the thin films was investigated through degradation of aqueous formic acid under UV–visible light. The Langmuir–Hinshelwood kinetic model was used to interpret quantitatively the observed kinetic experimental result. Comparative study of the obtained coated surfaces with those of uncoated surfaces, demonstrated a remarkable performance. The Fe/TiO 2 films and their calcination at 650°C demonstrated the highest photocatalytic activity.