Synthesis of TiO₂ nanotubes by atmospheric microplasma electrochemistry: Fabrication, characterization and TiO₂ oxide film properties

This work is devoted to synthesize Titanium Oxide (TiO₂) nanotubes (NT) on a titanium foil by atmospheric-pressure argon microplasma-assisted electrochemistry in an organic electrolyte with electrolytes composed of ethylene glycol (EG), acid fluoride (HF), and water. The morphology, as well as the form and structure of nanotubes were characterized by XRD, field-emission scanning electron microscopy (FESEM), Raman spectroscopy and EDS. The emission spectroscopy has showed the appearance of N₂, OH and O lines in addition to Ar lines above and near the solution surface. The nanotubes composed of Ti and O with various diameter/length and distributions were obtained in the different plasma electrical conditions. FESEM images were indicated that, owing to the cathode structure, diameter and length of the nanotubes increased from 20–25 nm to 50–70 nm and 1.3 to 3.8 μm when the current increased from 3 to 7 mA, respectively. A further investigations on crystallinity of TiO₂ nanotubes and porosity (P) of the layers revealed that the microplasma as a gaseous electrode could accelerate the rate of the titanium oxidation and dissolution of titanium oxide.