This study has been conducted with the objective of investigating the effects of zinc oxide nanoparticles on the structural and electrical properties of polyvinyl alcohol films. The fabricated nanocomposites were characterised by Fourier transform infrared spectroscopy, UV-visible (vis) spectra, X-ray diffraction and SEM techniques. UV-vis spectra showed that the addition of ZnO nanoparticles did not affect the absorbance in the visible region of nanocomposites. The SEM image showed that ZnO nanoparticles were homogeneously dispersed throughout the entire film's polymeric matrix. The dielectric properties were found to be strongly dependent on frequency and nanofiller content. AC conductivity s ac of polyvinyl alcohol/ZnO nanocomposites increased with increasing frequency. The dissipation factor tan d also increased with nanoparticle addition and decreased with frequency. At low nanofiller concentrations, nanocomposites exhibited low dielectric values at higher frequency, thus behaving like a lossless material, making them suitable for utilisation in microwave applications.

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Progress in material science has unearthed a number of options that offer great advantages for nanostructured electrode materials which enable supercapacitors to operate efficiently. Present work involves fabrication of symmetric and asymmetric type supercapacitor devices utilizing Mn-CuO nanostructures and activated carbon (AC) as electrode materials and subsequent investigation on their supercapacitive performance in 2M KOH aqueous electrolyte. The asymmetric supercapacitor device (Mn-CuO // 2M KOH// AC) demonstrate a specific capacitance of 72 Fg-1 at a current density of 0.5 Ag-1. The cyclic stability test of this device performed at a current density of 10 Ag-1 reveals a capacitance retention of 71% of its initial value over 300 charge-discharge cycles. In addition, this device exhibits an energy density of 7.4 Whkg-1 and a power density of 127 Wkg-1.

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