Experimental investigations on NO2 sensing of pure ZnO and PANI-ZnO composite thin films

In the present work, comparative investigations on NO2 gas sensing properties of the hybrid nanocomposite thin films of polyaniline (PANI), ZnO and PANI-ZnO towards NO2 gas at room temperature have been reported. The effect of concentration of PANI in the composite thin films on NO2 gas sensing has been investigated. Structural and surface morphological characterizations have been carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The presence of 5 wt% PANI in the composite films was found to give a maximum sensing response of similar to 6.11 x 10(2) towards 20 ppm NO2 gas having fast response and recovery time of about 2.16 min and 3.5 min respectively.