Fabrication mechanism of compact TiO2 nanotubes and their photo-electrochemical ability

Abstract

Ordered compact TiO2 nanotubes have been fabricated by using third generation electrolyte on employing the electrochemical anodisation technique. The titania nanotube growth is intiated by etching the oxide layer due to fluoride ions in the prepared electrolyte therby results the pore formation which continue to deepen in the oxide layer by maintaining the atmosphere of high and low pH at the mouth and bottom of the titania nanotubes, respectively. Using field emission scanning electron microscope (FESEM) and anodization current time spectra, detailed fabrication mechanism of compact TiO2 nanotubes have been explained. Moreover, the resulting TiO2 nanotubes were studied for light absorption using diffuse reflectance spectroscopy and photo-eletrochemical property using electrochemical analyzer. The absorption and photo-electrochemical spectra of the resulting titania nanotubes show the band gap of ~3.2 eV and photocurrent density of ~4.85 mA cm−2 respectively. The elemental composition and phase purity of the finally prepared compact TiO2 nanotubes (anatase) were confirmed by EDAX coupled with FESEM and x-ray diffractogram, respectively.