Preparation of fine, uniform nitrogen- and sulfur-modified TiO₂nanoparticles from titania nanotubes

Abstract

TiO 2 nanoparticles modified with nitrogen and sulfur were prepared from titania nanotubes by a facile wet chemistry method. The samples synthesized with different thiourea/TiO 2 ratios showed a uniform nanoparticle size distribution centred at approximately 10 nm with a developed specific surface area of 246 m 2 g −1 . These modified nanosized photocatalysts exhibited higher photocatalytic activity for the degradation of gaseous isopropanol than unmodified titania nanotubes under visible illumination. This could be attributed to the synergistic effects of a large specific surface area, strong absorption in the visible region, a redshift in the adsorption edge, and surface adsorption modification induced by nitrogen and sulfur compounds.

Laser Synthesis and Characterization of Nitrogen-Doped TiO2 Vertically Aligned Columnar Array Photocatalysts

“…The reduction of the band gap allowing absorption in the visible region, ∼42% of the solar spectrum, would have huge implications toward the efficient use of clean and renewable solar energy. Much attention has been focused on the development of non-metal-ion doped TiO 2 , and among these studies, the nitrogen doping has become one of the hottest topics during the last years in the field. − Various discrepancies exist in the literature concerning efficient doping of TiO 2 , mainly due to the different synthesis techniques inducing oxygen stoichiometry variations, inclusion of nitrogen in the TiO 2 structure either in substitutional or interstitial sites, or formation of different impurity energy levels. There exists the need for the development of techniques that ensure doping and therefore tuning of the optical band gap in a controlled manner.…”

Mechanisms of Phase Transformations of TiO2 Nanotubes and Nanorods

“…The wall thickness of anT and amT was set to 3.0 and 2.7 nm, respectively, which is slightly larger than the minimum size that can be modeled by MA. The outer diameter of anT and amT was set to 9.3 and 13.2 nm, respectively, which is close to experimentally synthesized − TiO 2 nanotubes with diameters in the range 4–15 nm. The smallest number of atomic sites simulated is 10620, and the largest is 31392.…”