Synthesis, Characterization and CO2 Gas Sensing Response of 5% SnO2 Doped Polyaniline Nano Composite

Abstract

Polyaniline and its nano-composites are synthesized using in-situ chemical oxidative polymerization technique using aniline. Nano sized SnO2 is used as received from the manufacturer. Ammonium Per Sulphate is used as oxidizing agent for polymerization. Crystalline SnO2 is embedded in amorphous Polyaniline. The structure of the composite was confirmed by the characterization techniques FTIR, UV Visible and XRD. Average particle size and chain separation is determined using XRD. The little shifting of the wavelengths towards higher values in FTIR confirms the formation of Polyaniline. UV Visible studies show that the composite exhibit absorption peaks at 614 nm, 328 nm and 263 nm; which corresponds to band gap energies 2.02 eV, 3.78 eV and 4.71 eV respectively. V-I characteristic is plotted using two probe method, which indicate fairly linear or ohmic behavior of the sample with high resistivity. Gas sensing response to CO2 is observed.