Pure TiO 2 and TiO 2 nanotubular arrays were successfully sensitized. Nanotubular arrays were prepared by electrochemical anodization of thin films of Ti and of Ti-Nb deposited on alumina substrates with two different roughness. Morphological characterization and functional properties are presented. The gas sensing properties of TiO 2 and TiO 2 nanotubes with different gases have been tested in a wide range of operating temperatures. © 2011 Published by Elsevier Ltd.