Fabrication and Gas Sensitivity Study of Polypyrrole/Titanium Oxide Composite Thin Films

Polypyrrole/Titanium Oxide (PPy/TiO2) nanocomposite thin films prepared by in situ chemical oxidation polymerization and electrostatic self-assembly combined technique were investigated. The films were characterized with UV-Vis spectroscope and atomic force microscope. With the assistance of interdigitated electrodes, gas sensors using PPy/TiO2 nanocomposite thin films were achieved. The sensitivities of sensors to toxic gases NH3 and CO at room temperature were studied. Temperature and humidity sensitive properties were also tested. The results show that the sensor can detect NH3 with high sensitivity, whereas can not recognize CO almost. The investigation of the effects of film depositing time .on sensor sensitivities shows that the sensors with the composite thin film deposited for 20min possess the highest sensitivity to NH3.