Preparation, Characterization and Comparative NH3-sensing Characteristic Studies of PANI/inorganic Oxides Nanocomposite Thin Films

Polyaniline (PANI), polyaniline/titanium dioxide (PANI/TiO2), polyaniline/tin oxide (PANI/SnO2) and polyaniline/indium oxide (PANI/In2O3) thin films were developed by using an in-situ self-assembly method at similar to 10 degrees C. Chemical structure, optical property and morphology of all the thin films were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-Vis absorption spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). NH3 gas-sensing properties of PANI and PANI nanocomposite thin films were examined at ambient temperature. The results showed that all the sensors composed of PANI nanocomposite thin films had faster response/recovery rate with better reproducibility, selectivity and long-term stability to NH3 than PANI thin film sensor, and PANI/TiO2 nanocomposite thin film sensor showed optimum NH3 gas-sensing characteristics. The effect of humidity on the responses of all the sensors was also investigated.