Enhanced Opto-Electric Properties of PVA-CMC Blends with Cu2WS4@GNR Heterojunction for Advanced Applications

This study investigates the enhancement of the opto-electric properties of polyvinyl alcohol (PVA) and carboxy methyl cellulose (CMC) blend through the incorporation of different amounts of synthesized copper tungsten sulfide (CWS) nanoparticles and graphene nanoribbon (GNR) as nanofillers of 0.0 %, 1.0 %, 2.0 %, 4.0 % and 8.0 wt/wt % by using eco-friendly solution casting method. Various characterization techniques were employed to analyze the synthesized nanoparticles and prepared polymer nanocomposites (PNCs) morphology, microcrystalline parameters, optical, electrical and dielectric properties via Scanning Electron microscopy (SEM), X-ray diffraction (XRD), UV-visible spectroscopy and LCR meter respectively. Fourier Transform Infrared Spectroscopy (FTIR) was utilized to understand molecular interactions of functional groups present in the synthesized NCs. Raman spectroscopy revealed molecular vibrations and the chemical composition of the materials. The presence of CWS and GNR leads to a considerable enhancement in the intensity of the PL peak observed at around 425 and 470 nm. The UV-visible spectra show the maximum absorption at 202.5 nm and at 363 nm due to the interaction between the functional group of polymers and nanofillers in the UV region. The optical band gaps were 2.77 eV (indirect) and 5.38 eV (direct) initially. The addition of the nanofiller resulted in a decrease in the indirect band gap to 2.59 eV and a reduction in the direct band gap to 4.19 eV, along with enhancements in other optical properties. Furthermore, the dielectric behaviour, including dielectric constant, loss, and AC conductivity, was systematically evaluated across various frequencies. The study indicates the substantial change in the composite's dielectric properties, making it a promising candidate for use in advanced opto-electronic devices.