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.