Gas sensitivity of polypyrrole films to NO2

Abstract

We have shown that the gas sensitivity of electropolymerized polypyrrole films to NO₂ in an N₂ atmosphere at room temperature is enhanced by the elimination of dopant anions using an electrochemical reduction procedure. Fourier-transform infrared spectra of polypyrrole films which had been reduced and then exposed to NO₂ showed that NO^– ₂ species were produced by the exposure to NO₂, indicating that the gas sensitivity results mainly from chemical doping by NO₂.