Highly-ordered, densely-packed, hexagonal TiO2 nanotubes were synthesized in a single-step anodization of Ti foil using a constant dc potential of 60 V. The synthesized nanotubes exhibit a bamboo-like structure, with rings formed along the length. X-ray diffraction reveals the as-grown nanotubes to be amorphous, which upon annealing at 723 K changes to a dominantly crystalline anatase phase. A high concentration of the electrolyte coupled with a mechanically uneven Ti surface leads to “nano-grass” like structure. A long anodization time also contributes to rapid breakdown of the Nanotubes.