Active TiO2 nanotubes for CO oxidation at low temperature

In this study we report the formation of nanocrystals and nanotubes of TiO2 synthesized by the sol-gel method and hydrothermal treatment respectively. The obtained TiO2 nanostructures were characterized by XRD, BET, TEM, UV-vis, XPS and FTIR; and evaluated in the CO oxidation. As for the nanotube-based samples, two catalysts were prepared (NTB5 and NTB10) through the hydrothermal treatment of nanosized titania in NaOH (5 and 10N) at 160 degrees C, followed by HCl rinsing until pH 1 was reached. From both catalysts, NTB10 showed the highest surface area (290 m(2)/g), nanocrystals (15 nm) and stable phase (H2Ti3O7) with a high CO oxidation capacity. We found that the band gap for NTB10 catalyst was of 2.85 eV, the lowest value respect to that of NTB5 and SGTB3 catalyst, based material (SGTB) showed both the lowest textural properties and catalytic performance. (C) 2011 Elsevier B.V. All rights reserved.