Facile Fabrication of Open-Ended High Aspect-Ratio Anodic TiO₂ Nanotube Films and their Applications

Abstract

In the present work, we demonstrated a facile process to prepare an open-ended high aspect-ratio TiO2 nanotube films through separating the anodic TNT array from the Ti substrate by a small reverse bias and opening the tube bottom by a chemical etching. The possible mechanisms of film detachment and pore opening processes have been briefly discussed. Such a process allows controlling the open-ended morphology by the straightforward chemical etching, which shows great potential in many applications, such as flow-through photocatalytic reactions, biofiltration, and diffusion controlling, and so on. An example using the open-ended TNT films is finally given as a flow-through photocatalytic reactor. The photocatalytic film has been shown to have multiple functions such as physical separation of contaminants, filtration, and decomposition of organic pollutants during diffusion.

TiO2 as an Anode of High-Performance Lithium-Ion Batteries: A Comprehensive Review towards Practical Application

“…Optimum voltage tuned with the proper time causes improved geometry regarding both length and diameter. In addition, 60 V 3 h anodization results in high 46 µm thick nanotubular structures with 120 nm tube diameter [137], whereas, 30 V 45 min anodization results in 1.2 µm thick nanotubes [138]. High applied voltage causes spark anodization on the Ti surface [139].…”

Fabrication of high aspect ratio and open‐ended TiO2 nanotube photocatalytic arrays through electrochemical anodization

“…Various methods involving anodization have been reported for the fabrication of flow‐through TiNT membrane mainly by chemically opening the closed bottom end of the TiNT array. Prior to the chemical dissolution of the closed bottom end, free‐standing TiNT arrays were first obtained either by selective metal dissolution, by chemical assisted separation, by applying reverse bias, or by ultrasonic agitation to detach the NT arrays from the metal substrate. The detached TiNT arrays were then exposed to hazardous chemicals such as HF acid solution and vapour, oxalic acid solution, and NH 4 F – H 2 SO 4 solution for suitable time length to obtain flow‐through TiNT membranes.…”