Structure and room temperature gas-sensing properties of Pd- functionalized TeO2 nanowire sensors

초록

TeO2 one-dimensional (1D) nanostrutures were synthesized by thermal evaporation of Te powders. The morphology, crystal structure, and response properties of the Pd-functionalized nanostructures to H2S gas at room temperature were investigated. The diameter of the 1D nanostructures was in a range from a few tens to a few hundreds of nanometers and the length was up to a few tens of micrometers. The gas sensors fabricated from multiple networked TeO2 nanowires functionalized with Pd showed the enhanced electrical responses to H2S gas at room temperature. The sensitivity of the TiO2 nanowires was improved by a factor of higher than 3 at a H2S concentration of 100 ppm by Pd-functionalization at room temperature. Both the response and recovery times of the nanowire sensor for H2S gas sensing were shortened by more than 20%. In addition, the mechanism for the improvement in the gas sensing characteristics of TeO2 nanorods by Pd functionalization are discussed.