CNT-ZnO Nanocomposite Thin Films: O2 and NO2 Sensing

The CNT-ZnO nanocomposites were synthesized by addition of commercially available MWCNT during growth of ZnO nanoparticles employing a wet chemical route. These nanocomposites were then spin coated and characterized using X-ray diffraction, scanning electron microscopy, current-voltage characteristics and O2 (5-20%) / NO2 (2-20 ppm) gas sensing at 250°C operating temperature in N2 atmosphere (0.4±0.03 mbar). The addition of CNT in ZnO is found to increase the sensitivity for both O2 and NO2 gas sensing. The 0.1 wt % CNT addition in ZnO is observed to appreciably enhance the NO2 gas sensitivity while 1.0 wt % CNT addition in ZnO showed highest sensitivity for O2 gas detection.