Preparation and gas sensing properties of undoped and Pd-doped TiO2 nanowires

Titanium dioxide (TiO2) nanowires with a rutile structure were prepared by thermal evaporation method using Ti metal powder as a raw material. The major factor that influenced the morphology was the furnace temperature. The uniform nanowires can be prepared at the furnace temperature of 1200 degrees C, which were approximately 50-220 nm in diameter and several tens of micrometers in length. Sensors were fabricated by pouring a few drops of product suspended ethanol onto oxidized Si substrates equipped with a pair of interdigitated Pt electrodes and H-2 gas sensing properties were investigated. Both undoped and Pd-doped TiO2 nanowire gas sensors showed the highest response at 100 degrees C. Comparing with undoped nanowire sensor, Pd-doped nanowire sensor exhibited much higher response and rapider response/recover characteristic to H-2 gas. The results demonstrated that Pd-doped TiO2 nanowires can be used to fabricate high performance H-2 sensors. (c) 2013 Elsevier B. V. All rights reserved.