Synthesis and characterization of TiO 2 doped polyaniline composites for hydrogen gas sensing

Abstract

The Polyaniline (PANI) and Titanium dioxide (TiO 2)/PANI composite thin film based chemiresistor type gas sensors for hydrogen (H 2) gas sensing application are presented in this paper. Pure PANI and TiO 2/PANI composites with different wt% of TiO 2 were synthesized by chemical oxidative polymerization of aniline using ammonium persulfate in acidic medium at 0–5 °C. Thin films of PANI and TiO 2/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 H 2 gas was evaluated by monitoring the change in electrical resistance at room temperature. It was observed that the TiO 2/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.