TS Science

Zinc ferrite (ZnFe₂O₄) nanoparticles were synthesized by the co-precipitation method, producing a spinel phase with an average crystallite size of ∼34 nm. These nanoparticles were then incorporated into a polyvinylpyrrolidone (PVP) and sodium alginate (NaAlg) blend matrix using the solution casting technique to fabricate nanocomposites. Structural characterization confirmed the successful dispersion of ZnFe₂O₄ within the polymer matrix and revealed a decrease in crystallinity upon nanoparticle addition. FTIR spectra indicated strong interactions between Zn/Fe ions and polymer functional groups, leading to partial amorphization. UV–Vis spectroscopy revealed that as the nanofiller concentration increased, the material's ability to absorb light was enhanced, decreasing its transparency. This effect was directly correlated with a progressive narrowing of the direct and indirect band gaps, which were reduced to 4.16 eV and 2.53 eV, respectively, from their initial values of 5.03 eV and 4.57 eV. Dielectric measurements demonstrated enhanced permittivity at low frequencies due to interfacial polarization and a consistent improvement in AC conductivity with nanoparticle loading. The dielectric constant increased from 10 to 60 after adding 2.4 wt% of the nanofiller. The Modulus and Argand plot analyses provided evidence of a non-Debye-type relaxation mechanism, suggesting an enhancement in charge transport properties. Overall, the tailored optical and dielectric behaviors suggest that PVP/NaAlg–ZnFe₂O₄ nanocomposites hold significant promise for optoelectronic, dielectric, and energy-related applications