Enhancing Optical and Electrical Gas Sensing Properties of Polypyrrole Nanoplate by Dispersing Nano-Sized Tungsten Oxide

Abstract

Pure polypyrrole (PPy) and tungsten oxide (WO3) nanostructures were produced and combined with specific ratios of WO3. to prepare PPy-WO3 hybrid nanocomposite thin films using the drop-casting process on a silicon substrate. The morphology of PPy, WO3, and PPy-WO3 was examined by field emission scanning electron microscopy and we found that the substance is nanoplates. Due to the quantum confinement effect, the optical energy gap of PPy increased from 3.58 eV to 3.92 and 4.21 eV upon incorporating 10 and 20% of WO3, respectively. At ambient temperature, the DC-conductivity of synthetic PPy was found to be 7.3 × 10−2 S cm−1 and this significantly increases when WO3 is added, which is accompanied by a change in the activation energies of the hybrid nanocomposite. The response and recovery times, as well as the sensitivity as a function of time and operating temperature, of pure PPy nanoplate and PPy-WO3 hybrid nanocomposites films for nitrogen dioxide (NO2) sensing were investigated. The PPy-WO3 hybrid nanocomposites exhibited a lower response time and higher sensitivity than pure PPy. The enhancement in the sensitivity of the PPy-WO3 hybrid nanocomposites to NO2 is ascribed to the synergistic effect between PPy and WO3.