Synthesis and improved optical, electrical, and dielectric properties of PEO/PVA/CuCo2O4 nanocomposites.

ABSTRACT

This study investigates the development of novel nanocomposite films based on a blend of polyethylene oxide (PEO) and polyvinyl alcohol (PVA) loaded with varying weight percentages of copper cobaltite nanoparticles (CuCo2O4 NPs). The primary objective was to fabricate these nanocomposites using a solution casting technique and explore the influence of CuCo2O4 content on their structural, optical, electrical, and dielectric properties. Spinel-type CuCo2O4 NPs were synthesized via the hydrothermal method and incorporated into the PEO/PVA blend. X-ray diffraction (XRD) analysis revealed the transformation of the polymer matrix towards an amorphous state with increasing CuCo2O4 content. UV-Vis spectroscopy studies demonstrated a decrease in both the direct and indirect band gaps of the nanocomposites, suggesting potential applications in optoelectronic devices. Impedance spectroscopy measurements revealed a significant enhancement in ionic conductivity (three orders of magnitude higher than the pristine blend) for the nanocomposite film containing 1.8 wt% CuCo2O4. The real permittivity (ε') and imaginary permittivity (ε″) of the polymer nanocomposites exhibited a decrease with increasing frequency due to the interplay of various polarization mechanisms. Notably, incorporating 1.8 wt% CuCo2O4 nanoparticles led to a remarkable improvement in energy density compared to the pristine blend. Additionally, a significant decrease in the potential barrier was observed. These findings demonstrate the successful fabrication of PEO/PVA-CuCo2O4 nanocomposite films with enhanced optical, electrical, and dielectric properties. The observed improvements suggest promising applications for these materials in energy storage devices and potentially in optoelectronic devices like light-emitting diodes.