Comparative NH3-sensing characteristic studies of PANI/TiO2 nanocomposite thin films doped with different acids

Polyaniline/titanium dioxide (PANI/TiO2) nanocomposite thin films were synthesized by in-situ self-assembly method, which were doped with p-toluene sulphonic acid (p-TSA) and hydrochloric acid (HCl), respectively. The thin films were characterized by using UV-Vis absorption spectroscopy and scanning electron microscope (SEM), and the NH3 gas sensitive properties of the thin films were investigated at room temperature. The results showed that the PANI/TiO2 thin film doped with HCl was superior to that doped with p-TSA in terms of response-recovery characteristics. The surface morphology characterization of the thin films were performed to explain the different gas-sensing properties.