DC electrical conductivity and rate of ammonia vapour-sensing performance of synthetic polypyrrole–zirconium(IV) phosphate cation exchange nanocomposite

Electrically conductive polypyrrole–zirconium( IV) phosphate (PPy–ZrP) cation exchange nanocomposites have been synthesized for the first time by in situ chemical oxidative polymerization of pyrrole in the presence of zirconium(IV) phosphate (ZrP). Fourier Transform Infra-red spectroscopy (FTIR), field emission scanning electron microscopy, transmission electron microscopy, X–ray diffraction, thermogravimetric analysis, differential thermal analysis, derivative thermogravimetry and elemental analysis were used to characterize PPy–ZrP cation exchange nanocomposite. The composite showed good ion-exchange capacity (1.60 meq g^-1), DC electrical conductivity (0.33 S cm^-1) and isothermal stability in terms of DC electrical conductivity retention under ambient condition up to 100 ◦ C. PPy–ZrP cation exchangenanocomposite- based sensor was fabricated for the detection of ammonia vapours of aqueous ammonia. The resistivity of the nanocomposites increases on exposure to high-concentration ammonia vapours at room temperature (25 ◦ C). The rate of reaction for ammonia vapour-sensing on PPy–ZrP was observed as second order.