Growing TiO₃-based pillars by chemisorbed nanotitania followed by annealing

A templateless, efficient, and straightforward method is developed for die growth of TiO₂-based microstructures perpendicular to die 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 TiO ₂, and die previously anticipated mechanism for titania nanotubes synthesized by a soft chemical route supports me proposed growth mechanism. The electrodes grown on fluorine-doped tin oxide (FTO) glass substrates showed a moderate performance in dye-sensitized solar cells.