TiO2 nanobelts were prepared by the hydrothermal growth method. The surface of the nanobelts was coarsened by selective acid corrosion and functionalized with Pd catalyst particles. Three nanobelt samples (TiO2 nanobelts, surface-coarsened TiO2 nanobelts and Pd nanoparticle/TiO2 nanobelt surface heterostructures) were configured as gas sensors and their sensing ability was measured. Both the surface-coarsened nanobelts and the Pd nanoparticle-decorated TiO2 nanobelts exhibited dramatically improved sensitivity to ethanol vapor. Pd nanoparticle-decorated TiO2 nanobelts with surface heterostructures exhibited the best sensitivity, selectivity, working temperature, response/recovery time, and reproducibility. The excellent ethanol sensing performance is attributed to the large surface area and enhancement by Schottky barrier-type junctions between the Pd nanoparticles and TiO2 nanobelts. (C) 2012 Elsevier Inc. All rights reserved.