Effects of atomic oxygen on titanium dioxide thin film

Abstract In low earth orbit (LEO), atomic oxygen (AO) has shown to cause degradation of organic materials used in spacecrafts. Similar to other metal oxides such as SiO 2 , Al 2 O 3 and ITO, TiO 2 has potential to protect organic materials. In this study, the anatese-type TiO 2 thin films were fabricated by a sol-gel method and irradiated with AO. The properties of TiO 2 were compared using mass change, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmittance spectra and photocatalytic activity before and after AO irradiation. The results indicate that TiO 2 film was hardly eroded and resistant against AO degradation. AO was shown to affects only the surface of a TiO 2 film and not the bulk. Upon AO irradiation, the TiO 2 films were slightly oxidized. However, these changes were very small. Photocatalytic activity of TiO 2 was still maintained in spite of slight decrease upon AO irradiation, which demonstrated that TiO 2 thin films are promising for elimination of contaminations outgassed from a spacecraft's materials.