Fabrication of Self-Organized TiO2 Nano-tubes by Anodizing of Pure Titanium

Nano-tubes are of great interest due to their high surface-to-volume ratios and size dependent properties [1]. A range of materials such as Al, Si, InP, Hf, Zr, Nb, W, and Ti, has been recently found to form self-organized porous structures under optimized electrochemical treatments [2]. These oxide films usually have specific functional properties, which may be exploited in optics, electronics, photochemistry, or biology. For example, titanium oxide is a promising material because of gas-sensing capabilities, self-cleaning ability, and its use in solar cells, photo and thermal catalysis, controllable wetability, and improvement of biocompatibility [2-3]. Nano-tubes have been produced by a variety of methods including deposition into a nano-porous alumina template, sol–gel transcription using organo-gelators as templates, seeded growth, and hydrothermal processes. Meanwhile, anodization process can control the dimensions of produced titania precisely [4]. In this work, Self-organized titanium oxide nano-tube has been synthesized by electrochemical anodization of Ti foil in an electrolyte containing fluoride. Anodic production of self-organized titanium oxide in a fluoride bath was studied in various potentials and times. Anodizing process was implemented in ambient temperature by DC current source; Morphology and structure of nano-tubes were also studied by SEM images. Moreover, appropriate potential, time and bath conditions were investigated due to create ordered nano-tubes. Indeed, Nano-tubes with various internal diameter of 80-110nm were fabricated in a 17-22V potential range. Ordered nano-tubes with almost length of 1-2.5mμ and density of 8.1*109 Cm-2 were uniformly grown