In situ Bi2O3-loaded polypyrrole nanocomposites for carbon dioxide gas sensing

Abstract

In the present work, an attempt has been made to detect carbon dioxide (CO2) using an in situ-loaded Bi2O3–polypyrrole nanocomposite sensor. The polypyrrole (PPy) was prepared by oxidative polymerization method from precursor’s monomer pyrrole and aqueous solution of ammonium persulphate. The prepared nanocomposites were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric–differential thermal analysis (TG–DTA) and Raman spectroscopy. Thick films of the synthesized PPy nanocomposites were deposited on glass substrate by screen printing technique. Resistive type gas sensors are extensively used in a number of modern applications such as emission control and energy efficiency. By considering this view, PPy nanocomposite films were prepared for gas sensing application. The XRD analysis revealed amorphous nature. The SEM micrograph showed that nanocomposite particles have irregular morphology and size. The nanocomposites showed a good sensing performance toward CO2 gas. The highest value of CO2 gas sensing response was shown by 25 wt% Bi2O3-loaded PPy nanocomposite sample (S5), which was found to be 0.065 for 50 ppm. Operating temperature for the optimized sample S5 toward CO2 gas was found to be 363 K. Similarly, the optimized sample S5 showed an excellent stability response against CO2 gas and atmospheric change for 30 days.