Controlled Synthesis of Polyaniline/Iron Oxide Nanocomposites for Thermoelectric Applications

Polyaniline (PANI) / iron oxide (Fe3O4) nanocomposites were synthesized via the sol-gel method by tuning the weight ratios of Fe3O4 (2wt %, 4wt % and 6wt %). The functional groups, crystal structure and surface morphologies of the PANI/Fe3O4 nanocomposites were analyzed using Fourier transform infrared spectroscopy (FTIR), X–ray powder diffraction and Scanning electron microscopy (SEM) respectively. The thermoelectrical properties were also analyzed. Based on the FTIR studies, the presence of functional groups of PANI/Fe3O4 nanocomposites was revealed. From SEM observations, spherical nanoparticles were found. As the temperature increases from 30°C to 90°C, the electrical conductivity of the nanocomposites increases from 34.01 to 39.54 mS/cm and the thermal conductivity decreases from 1.401 to 0.765 Wm-1K-1. Among the three different PANI/Fe3O4 nanocomposites characterized, the PANI/Fe3O4 nanocomposite with 6wt % gives better results by showing an excess figure of merit of 0.016. Henceforth, as the weight percentage of iron oxide with polyaniline increases, the thermoelectric properties of the nanocomposites drastically improve.