Dense and high-hydrophobic rutile TiO2 nanorod arrays

Dense and well-oriented rutile TiO₂ nanorod arrays were synthesized on a titanium substrate using the organic compound dibutyltin dilaurate as the oxygen source in the oxidation of Ti at 850 °C. The influence of temperature on the nanostructured TiO₂ formation and the effect of the TiO₂ structures on their wettability were also investigated. Polycrystalline TiO₂ grains were formed at 800 °C; in contrast, TiO₂ micro-whiskers were grown on the Ti substrate at 900 °C. The measurement of the water contact angle shows that the wetting property of the TiO₂ films strongly depends on their surface structure. The surface of the dense well-oriented nanorod arrays is highly hydrophobic with a water contact angle of 130 °C. This study has demonstrated that the direct oxidation of Ti substrate using an organic oxygen source is a promising method for fabrication of large scale, uniform and well-aligned TiO₂ nanorod arrays on titanium substrates. PACS 81.16.-Be; 81.20.ka; 82.4c.Cc; 68.37.Hk