Self-cleaning of a surface of nanotube arrays of anodic titanium oxide (ATO) is demonstrated. The ATO was prepared in fluoride ion containing sulfate electrolytes with a structure of 0.4∈μm length, 100∈nm pores diameter, 120∈nm interpore distance, 25∈nm pore wall thickness, a 8×10 9 pores∈cm -2 pore density, and 68.2% porosity. Prepared as thin films either directly from a Ti foil or on a glass substrate, these arrays have the property that water drops spread quickly over the surface of the films without irradiation. In contrast, a flat anatase TiO 2 film requires irradiation with UV light for several minutes before the contact angle decreases to zero. The observed self-cleaning behavior of the ATO thin films is due to the capillary effect of the nanochannel structure and the superhydrophilic property of the anatase TiO 2 surface inside the tube.
|Number of pages||6|
|Journal||Applied Physics A: Materials Science and Processing|
|State||Published - 1 Aug 2008|