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 850degreesC. 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 800degreesC; in contrast, TiO2 micro-whiskers were grown on the Ti substrate at 900degreesC. 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 130degreesC. 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.