TiO2–PANI nanocomposite thin film prepared by spin coating technique working as room temperature CO2 gas sensing

Present work reports the performance of a semiconducting PANI doped TiO2 nanocomposite thin film and its application in CO2 sensing. The TiO2–PANI nanocomposite layer was deposited on a simplified test device. Optical properties were investigated using UV–Vis absorption spectroscopy. The surface morphology and structure of synthesized material were characterized by TEM and XRD analysis, respectively. The structural analysis confirmed the formation of TiO2–PANI having an average crystallite size 7 nm. Variations in resistance with the exposure of CO2 to the sensing element were observed. Sensor response (S) as a function of time was calculated and its maximum value was found as 53 for 1000 ppm of CO2. Response and recovery times of the sensor were observed as 9.2 and 5.7 min respectively. Sensor was found reproducible.