Abstract:

Self-organized, freestanding titania (TiO₂) membrane with ultrahigh aspect ratio of the length/diameter (~1500) was fabricated via electrochemical anodization of highly pure titanium (Ti) foil in fluorine-containing ethylene glycol, followed by a simple and safe detachment of the formed TiO₂ membrane from the metallic Ti substrate. The resulting membrane consists of highly ordered, vertically aligned, one-side open TiO₂ nanotube arrays. The pore diameter, wall thickness, and length of the nanotube arrays are 90 nm, 15 nm, and 135 µm, respectively, at a certain anodization condition.