The Progress of TiO_𝟐 Nanocrystals Doped with Rare Earth Ions

Table 1

Comparison of current methods in TNT fabrication. Reprinted with permission from [32].

Fabrication method	Advantages	Disadvantages	TNT features
Template-assisted method	(1) The scale of nanotube can be moderately controlled by applied template	(1) Complicated fabrication process; (2) Tube morphology may be destroyed during fabrication process	Ordered arrays (powder form)
Electrochemical anodic oxidation method	(1) More desirable for practical applications; (2) Ordered alignment with high aspect ratio; (3) Feasible for extensive applications	(1) Mass production is limited; (2) Rapid formation kinetics is subjected to the utilization of HF; (3) Highly expense of fabrication apparatus	Oriented arrays (thin film)
Hydrothermal treatment	(1) Easy route to obtain nanotube morphology; (2) A number of modifications can be used to enhance the attributes of titanium nanotubes; (3) Feasible for extensive applications	(1) Long reaction duration is needed; (2) Highly concentrated NaOH must be added; (3) Difficult in achieving uniform size	Random alignment (powder form)