Fabrication and Characterization of PPy-PANI Composite Thin Films for Gas Sensing Applications

Abstract

This study investigates the structural, morphological, and gas sensing characteristics of pure polypyrrole (PPy), polyaniline (PANI), and their blends in varying ratios. X-ray diffraction (XRD) analysis revealed distinct diffraction peaks corresponding to the characteristic structures of PPy, PANI, and their blends, indicating successful composite formation and phase interactions. Field-emission scanning electron microscopy (FE-SEM) images showed porous, interconnected morphologies in composites, which enhance surface area and gas adsorption sites compared to pure polymers. Gas sensing tests demonstrated that the PPy:PANI blends with a 1:1 ratio exhibited superior sensitivity, rapid response, and recovery times at operating temperatures of 150 to 250 °C. This improvement is attributed to heterojunction formation, increased active sites, and enhanced charge transfer between the two polymers. The findings highlight the potential of PPy/PANI composites as efficient, stable, and high-performance gas sensors for environmental monitoring applications.