Dear Abdelhani, I am afraid, that it is impossible. If you want to see a formation, you need use one of the method: SEM, TEM or AFM. But the last one will show only topography of your coating.

What about X-Ray Diffraction(XRD)?

Dear Dr. Atilla Atli,

thank you for your contribution, but how can reveal the nanotubular structure by X-ray diffraction?

All my best

I am not sure to understand what the problem is. Do you want to see the beginning of the formation. Do you want to show that there is a formation of  TiO2 nanotube?. If really you want to see the shape of TiO2, the imagery would be the simplest way.

In XRD, you can verify the crystal structure of formed TiO2, May be you can play on the structure factor in XRD intensity expression, which would be different for a nanotube compared to that of a powder...  

I am not sure that XRD will give enough information bout the shape of the formed TiO2; if it is nano tubes or just normal type of oxide later or any shape.

One more thing, if the depth of the later is very small, XRD will hardly sense it, please consider.