Synthesis and spectroscopic characterisation of silver–polyaniline nanocomposite

Abstract

Nanocomposite of silver–polyaniline (Ag–PANI) has been synthesised by the in situ chemical polymerisation method using ammonium persulphate as an oxidising agent in the presence of sulphonic acid dopant. The synthesised Ag–PANI nanocomposite was subjected to the physicochemical characterisation using ultraviolet–visible and Fourier transform infrared spectroscopy. The ultraviolet–visible spectra of the synthesised nanocomposites show the presence of the characteristic absorption peak at ∼340 nm, which corresponds to the π−π* transition, and the shoulder at ∼420 nm corresponds to the polaronic peak of PANI. The surface plasmon resonance of the silver nanoparticles embedded in the polymer matrix, which is appearing at that wavelength, would have been overlapped by the polaronic peak of the PANI. The increasing absorption at higher wavelength confirms the formation of conducting emeraldine salt phase of the PANI, which is further supported by the Fourier transform infrared spectroscopy. The X-ray diffraction and energy dispersive spectroscopy study exposed the existence of silver nanoparticles in the elemental state. The morphology of the nanocomposites was characterised by SEM. Thermogravimetric analysis indicates an enhancement of the thermal stability of the nanocomposite compared with that of pure polymer. The Ag–PANI nanocomposite can be considered as a potential candidate for the applications in sensors, catalysis and electronic devices.