Dielectric and gas sensing properties of in situ electrochemically polymerized PPy-MgO-WO3 nanocomposite films

Abstract

     A polypyrrole-based ammonia-detection gas sensor was studied in this work. Under a 1.6 V electrodeposition potential, polypyrrole (PPy) was electrochemically synthesized from an aqueous solution of 0.1 M pyrrole and 0.1 M oxalic acid. An extension to the polypyrrole films was applied through electrochemical deposition on indium tin oxide (ITO), using the metal oxide nanoparticles of MgO and WO₃. These films were investigated for their sensing behavior towards NH₃ at different working temperatures and different weight percentages of nanoparticles .The measurements of A.C conductivity were conducted over a frequency range of 10¹-10⁵ Hz and temperature range of 298-423 K . The highest electrical conductivity was equal to 3.67x10^-1 Ω.cm^-1 at a temperature of 323 K and frequency of 10⁵H z. The experimental results showed that the sensitivity of the undoped and doped PPy with nanoparticle films to ammonia gas changes with the change in temperature and weight percentage.