Tailoring Polymer Nanostructures for Selective Hazardous Gas Sensing.

Abstract

This paper presents the development and characterization of polyaniline (PANI) and titanium dioxide (TiO2)/PANI composite thin film based chemiresistor type gas sensors for hydrogen (H2) detection. Pure PANI and (TiO2)/PANI composites with varying TiO2 weight percentages were synthesized via chemical oxidative polymerization of aniline using ammonium persulfate in an acidic medium at 0-5°C. The resulting thin films were deposited on copper interdigitated electrodes (IDEs) via spin coating to form the chemiresistor sensors. The H2 gas sensing response of these sensors was evaluated at room temperature by monitoring changes in their electrical resistance. Notably, TiO2/PANI composites exhibited significantly higher sensor sensitivity compared to pure PANI. Furthermore, the structural and optical properties of the composite films were comprehensively characterized using X-ray diffraction (XRD) and UV-visible (UV-Vis) spectroscopy. Detailed morphological and structural analysis was also performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).