TiO2/ SnO2;F composite thin films that have different amounts of TiO2 addition were deposited on sodalime glass by atmospheric pressure chemical vapor deposition (APCVD) and plasma enhanced chemical vapor deposition (PECVD) respectively and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). We confirm that the functional layers of SnO2;F and TiO2 yield to low-e and hydrophilic activity properties for the composite film, respectively. XRD results confirmed that the films were composed of TiO2 and SnO2;F. SEM images indicated that the as-prepared TiO2 films with thickness of 25 to 590nm, had rough surfaces and consisted of nano-sized particles. The photocatalytic activity of TiO2/SnO2;F thin films was evaluated by measuring the decolorization of Phodamine-B aqueous solution and showed higher photocatalytic activities that pure TiO2 films, which might mainly be due to the suppressed recombination by the bottom SnO2 layer. Water content angle (WCA) measurements indicated the surface wettabilities of TiO2/ SnO2:F bi-layer coatings were dramatically improved compared with pure TiO2 films, potentially due to the discharge separation between TiO2/SnO2:F. On the other hand the reflectance of composite films in the far-range infrared region decreases with the increasing of TiO2 film thickness.
