Effect of Dopants on the NH₃-Sensitive Chracteristics of Polyaniline-Titanium Dioxide Composite Thin Films

With planar interdigitated electrodes, polyaniline-titanium dioxide (PANI/TiO2) composite thin film gas sensor doped by hydrochloric acid and para toluene sulfonic acid (PTSA) respectively were prepared by combining in situ chemical oxidation polymerization and electrostatic self-assembly technique at the room temperature. The film characterized by scanning electron microscope (SEM). The sensitive properties of sensors to NH3 at room temperature were studied. The results show that the sensitivity, response and recovery characteristic, and the stability of PANI/TiO2 composite thin film doped by hydrochloric acid are superior to that of PANI/TiO2 composite thin film doped by PTSA. This study is helpful for the development of are NH3 sensitive device with low cost and high sensitivity.