Controllable preparation, growth mechanism and the properties research of TiO2 nanotube arrays

FESEM images of top view (a), fracture surface (b) and bottom view (c) of TiO2 nanotubes. The FESEM of titanium dioxide prepared in the glycol electrolyte which contains 0.5 wt% NH4F and 10 vol% H2O at room temperature and calcined 2 h at 450 °C, the oxidation voltage is 30 V and the oxidation time is 1 h. In the figure, (a) is the surface of titanium dioxide, from which we can see that the titanium dioxide nanotubes generated on titanium substrate is neatly, highly ordered, the tubular structure is uniform and clear, the inner diameter is about 60-100 nm. (b) is a lateral view of nanotubes, the length of nanotubes we measured is about 2.12 μm. (c) is the bottom figure of nanotube arrays, we can see that the bottom of the nanotubes is closed, well-organized. So we prepared the titanium dioxide nanotube arrays successfully.