(355c) Single Walled Carbon Nanotubes Based Ultra-Sensitive Resistor-Type Gas Sensors
Following facile synthetic procedures (electrospinning and membrane filtration), two single walled carbon nanotubes (SWNTs) based sensory materials have been prepared and applied for resistor-type gas detection. Both SWNTs based sensors have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and UV-Vis. Specifically, incorporation of SWNTs into PPy nanocomposites by electrospinning generates a novel SWNTs composite nanofibers and a synergistic effect between SWNTs and PPy, resulting in an improved NH3 detection limit as low as 36 ppb. Another SWNTs based sensor has been developed by the noncovalently immobilization of meso-tritolylcorrole (TTC) on SWNT networks through membrane filtration. This SWNT hybrid material possesses a donor-acceptor heterojunction through the π-π stacking, which facilitates exciton dissociation and thus greatly enhances the sensitivity towards NO2 detection. Our experimental results show great potential of novel SWNTs based sensory materials in gas detection.