Fabrication of TiO₂ Nanostructures on Ti₃SiC₂ Substrate by Anodic Oxidation.

A TiO2 nanostructure was prepared on a Ti3SiC2 substrate with different water and NH4F concentrations in a fluoride-containing ethylene glycol electrolyte via an anodization process using the same constant-anodization potentials, anodization duration and temperature. The as-prepared samples were characterized by a field-emission scanning electron microscope equipped with an energy dispersive X-ray spectroscope, as well as by X-ray diffraction and X-ray photoelectron spectroscopy. The influence of the anodizing parameters and annealing temperature on the morphology of the nanostructure and the phase structure was studied. The results showed that the scattered TiO2 nanotubes and TiO2 nanoporous films were successfully fabricated in the glycol electrolyte containing (3.0 wt%) NH4F +(5.0 vol%) H2O. The as-prepared samples before calcination were amorphous and could transform to the anatase phase at temperatures higher than 500 °C. As the annealing temperature increased, the crystallization of the anatase phase was enhanced, and the rutile phase appeared at 600 °C. The as-prepared samples mainly consisted of oxides. Ti2O3 and SiO2 oxides were present in addition to TiO2.