Growing TiO2-Based Pillars by Chemisorbed Nanotitania Followed by Annealing

Abstract

A templateless, efficient, and straightforward method is developed for the growth of TiO2-based microstructures perpendicular to the desired substrate. A variety of substrates coated by nanoparticles of TiO2, soaked in a 5 M NaOH solution for 2 h (chemisorption), and further annealed under air at 450 °C (4 h) fabricated a novel oriented, TiO2-based microarray comprised of nanotubes. Moreover, we verified that there is no need for both autoclaving (hydrothermal synthesis) and maintaining a lengthy reaction time for the growth of TiO2-based structures. The effect of several reaction parameters (solvent concentration, substrate nature, thickness and density of the seed nanotitania, and deposition of amorphous or crystalline TiO2) on the growth of the titania array is also demonstrated. The experimental results yielded the crystalline structure of anatase TiO2, and the previously anticipated mechanism for titania nanotubes synthesized by a soft chemical route supports the proposed growth mechanism. The electr...