Electrical conductivity and ammonia sensing studies on in situ polymerized poly(3-methythiophene)–titanium(IV)molybdophosphate cation exchange nanocomposite

Electrically conductive poly(3-methythiophene)-titanium(IV)molybdophosphate (P3MTh–TMP) cation exchange nanocomposites have been synthesized for the first time by in situ chemical oxidative polymerization of 3-methythiophene (3MTh) in the presence of titanium(IV)molybdophosphate (TMP). Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA) and elemental analysis were used to characterize P3MTh–TMP cation exchange nanocomposites. The characterization results confirmed that there is a strong interaction between P3MTh and TMP particles and the nanocomposites showed higher thermal stability than pure P3MTh. The composite showed good ion-exchange capacity, electrical conductivity and isothermal stability in terms of DC electrical conductivity retention under ambient condition below 100 °C. A cation exchange nanocomposite based sensor was fabricated for the detection of aqueous ammonia, it was found that the resistivity of the nanocomposites increases on exposure to ammonia at room temperature (25 °C) and there showed a linear relationship between the responses and the concentration of ammonia.