A comprehensive study on morphological, structural, optical, dielectric, and piezoelectric properties of polyvinyl alcohol/tantalum carbide—silicon dioxide nanocomposites for flexible energy storage devices

Abstract

The development of advanced materials with enhanced optical and electrical properties is critical for applications in photonic and electronic devices. This work's objective is to produce nanocomposites by casting and molding a polymeric mixture from polyvinyl alcohol (PVA) with two nanomaterial tantalum carbide (TaC) and silicon dioxide (SiO₂) nanoparticles with varying weight percentages (0, 1, 3, 5) wt%. The morphological, structural, optical, and electrical characteristics of PVA/TaC-SiO₂ nanocomposites were studied. When compared to pure polyvinyl alcohol (PVA), the samples show a change in peak location, shape, and intensity, as shown by FTIR analysis. Images taken using an optical microscope indicate that the nanoparticle dispersion of the mixture showed a uniform pattern, creating a cohesive network across the polymer matrix. At room temperature, the dielectric properties of the nanocomposites were investigated within the frequency range of 10²–10⁶ Hz. The experiment results indicate that the dielectric constant and dielectric loss decreased by increasing the frequency of the applied electric field, while electrical conductivity of alternating current (A.C) rose with rising frequency. The dielectric constant, dielectric loss, and A.C. electrical conductivity of pure PVA were shown to be positively correlated with the concentration of nanoparticles. The dielectric loss reached 2.3 at 5% at 100 Hz while dielectric constant reach to 58. The UV absorption of PVA/ TaC-SiO₂ nanocomposites is high. The results of the optical properties of nanocomposites PVA/ TaC-SiO₂ showed that as greater the number of nanoparticles (TaC-SiO₂), absorbance, absorption coefficient, extinction coefficient, refractive index, actual and imaginary dielectric constants, and optical conductivity were increases. The energy gap for allowed transitions fell from 4.25 to 1.9 eV, while the energy gap for forbidden transitions reduced from 3.99 to 1.2 eV, as the concentration of TaC-SiO₂ nanoparticles increases the transmittance decreases. The results show that PVA/TaC-SiO₂ NC films have outstanding optical and electrical properties, which may improve their use in a variety of electrical and photonic applications. The findings of the pressure sensor demonstrate that the PVA/TaC-SiO₂ nanostructures have superior environmental durability, remarkable flexibility, and excellent pressure sensitivity when compared to other sensors.