Iron nanoparticles embedded in polypyrrole and tellurium oxide ternary nanocomposites for electrical conductivity and electromagnetic interference shielding

The iron nanoparticles (FeNPs) embedded in polypyrrole (PPy/Fe) with tellurium oxide (PPy/Fe@TeO₂) nanocomposites were prepared by in situ polymerization using Green tea extract as a reducing and stabilizing agent. The iron nanoparticles were uniformly embedded with different concentrations (5–25 wt%) of TeO₂ (PPy/Fe@TeO₂) as ternary nanocomposites on the surface of PPy, so-called in situ functionalization through the redox reaction between PPy/Fe, TeO₂ and Green tea extract. The structural morphology was confirmed by various physicochemical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and tunneling electron microscopy (TEM). Electrical conductivity (DC & AC) and electromagnetic shielding interference (EMI) were recorded. The result shows that the DC conductivity increased as the weight percentage of TeO₂ in the composite decreased. The DC conductivity also increases slightly with an increase in temperature from 303 to 378 K. In addition, the alternating current (AC) conductivity of PPy/Fe@TeO₂ increases as a function of frequency, but this phenomenon was more strongly observed in the 15 wt% TeO₂ composite. Compared to other materials, the EMI shielding performance of the composite with a 15 wt% TeO₂ sample shows the largest performance loss between the 2.0 GHz and 3.0 GHz frequencies. The results show that the materials exhibit several desirable properties including AC, DC, and EMI shielding capabilities, and have the potential to be used in a variety of electronic applications such as biosensors and battery applications.