Comparative sensing of aldehyde and ammonia vapours on synthetic polypyrrole-Sn(IV)arsenotungstate nanocomposite cation exchange material

Polypyrrole-Sn(IV)arsenotungstate (PPy-SnAT) conductive nanocomposite cation exchange have been synthesized by in-situ chemical oxidative polymerization of polypyrrole with Sn(IV)arsenotungstate (SnAT). PPy-SnAT nanocomposite was characterized by Fourier transform infra-red spectroscopy (FTIR), X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray (EDX) and thermogravimetric analysis (TGA). The ion exchange capacity (IEC) and DC electrical conductivity of nanocomposite was found to be 2.50 meq/g and 5.05 × 10⁻¹ S/cm respectively. The nanocomposite showed appreciable isothermal stability in terms of DC electrical conductivity retention under ambient condition up to 130 °C. The nanocomposite cation exchange based sensor for detection of formaldehyde and ammonia vapours were fabricated at room temperature. It was revealed that the resistivity of the nanocomposite increases on exposure to higher percent concentration of ammonia and lower concentration of formaldehyde at room temperature (25 °C).