Enhancement of Thermoelectric Properties in Nanocomposites Through the Synergistic Integration of Zinc and Iron Oxides with Polyaniline

In this study, we systematically varied the weight ratios of zinc and iron oxides (2 wt%, 4 wt%, and 6 wt%) to fabricate nanocomposites consisting of polyaniline (PANI), zinc oxide (ZnO), and iron oxide (Fe3O4) through the sol–gel method. Comprehensive analyses using FTIR, XRD, and SEM were conducted to elucidate the functional groups, particle size, crystal structure, and surface morphologies of PANI/ZnO/Fe3O4 nanocomposites. Furthermore, thermoelectric characteristics were thoroughly investigated. A mechanistic insight into the PANI/ZnO/Fe3O4 nanocomposite formation was proposed based on the FTIR findings. SEM investigations revealed the presence of spherical particles in all nanocomposites. Among the three PANI/ZnO/Fe3O4 nanocomposites characterized, the formulation with 6 wt% exhibited superior thermoelectric performance. The electrical conductivity of the nanocomposites exhibited a notable increase from 23.1 to 42.7 mS/cm when the temperature elevated from 30–90 °C. Concurrently, the thermal conductivity exhibited a decline from 1.229 to 0.704 Wm−1K−1, resulting in an augmented figure of merit of 0.024. This enhancement underscores the positive influence of increasing the weight percentage of ZnO and Fe3O4 with PANI on the TE performances of the nanocomposites.