Anodic TiO2 Nanorod Arrays and Surface Wettability

We report a discovery of titanium dioxide nanorods that could be directly fabricated by electrochemical anodization in diethylene glycol medium. The anodization has been strictly performed in a particular condition using electrolyte mixture containing hydrofluoric acid and water, low anodization voltage, and controlled temperature bath at 20 degrees C, consequently yielding TiO2 nanorod arrays with size range of 30-50 nm. Analysing the current density slope, our finding has shown that the possible window to produce titania nanorod structure is limited by the rate of increment in current density, which is less than 10 mu A/cm(2)/h. The DEG-fabricated TiO2 nanorod array has exhibited the hydrophobic characteristic surface property with contact angles higher than 70 degrees, different than those commonly observed for the TiO2 nanotube array films grown in other organic electrolytes. Surface wettability relating to the array morphologies has been investigated. A schematic drawing demonstrated different views of relation among surface wettability, architectural morphologies, and electrolyte property.