Table 1.

Comparison of TiO₂ nanotube preparation methods.

References	Preparation Method	Growth Temperature (°C)	Crystal Structure	Possibility of Size Control	Template-Assisted Technique	Distribution over the Substrate	Starting Material
[36–39,47]	Electro-chemical anodization	Room temperature	Amorphous	Yes	No	Well-ordered and vertically-aligned	Metallic Ti
[40,42]	ALD	90–400	Amorphous/ crystalline	Yes	Yes	Well-ordered and vertically-aligned	Precursor solution
[17,44,45]	Hydrothermal synthesis	300–450	Titanate, anatase	Yes	No	Chaotic distribution (powder)	TiO2 crystalline nanoparticulate powder, precursor solution