Synthesis and characterization of TiO2 doped polyaniline composites for hydrogen gas sensing

The Polyaniline (PANI) and Titanium dioxide (TiO2)/PANI composite thin film based chemiresistor type gas sensors for hydrogen (H2) gas sensing application are presented in this paper. Pure PANI and TiO2/PANI composites with different wt% of TiO2 were synthesized by chemical oxidative polymerization of aniline using ammonium persulfate in acidic medium at 0–5 °C. Thin films of PANI and TiO2/PANI composites were deposited on copper (Cu) interdigited electrodes (IDE) by spin coating method to prepare the chemiresistor sensor. Finally, the response of these chemiresistor sensors for H2 gas was evaluated by monitoring the change in electrical resistance at room temperature. It was observed that the TiO2/PANI composite thin film based chemiresistor sensors show a higher response as compared to pure PANI sensor. The structural and optical properties of these composite films have been characterized by X-ray diffraction (XRD) and UV–Visible (UV–Vis) spectroscopy respectively. Morphological and structural properties of these composites have also been characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively.