Structural and Optical Characterization of g-C₃N₄ Nanosheet Integrated PVC/PVP Polymer Nanocomposites

The present work considers the integration of g-C₃N₄ nanosheets into PVC/PVP polymer nanocomposites at ratios of 0.0, 0.3, 0.6, and 1.0 wt%. The XRD data scans showed semicrystalline structures for all PVC/PVP/g-C₃N₄ polymer blend films. The FTIR and Raman measurements revealed intermolecular hydrogen bonding between the g-C₃N₄ surface and the OH^- groups of the PVC/PVP network. ESEM morphology analysis for PVC/PVP/g-C₃N₄ nanocomposite films displayed homogeneous surface textures. The data of TGA showed improved thermal stability as the decomposition temperature increased from 262 to 276 °C with the content of g-C₃N₄ (0.0-1.0 wt%). The optical absorbance data for PVC/PVP films improved after the addition of g-C₃N₄. The optical energy gaps showed compositional dependence on the g-C₃N₄ content, which changed from 5.23 to 5.34 eV at indirect allowed transitions. The refractive index for these blend films enhanced (1.83-3.96) with the inclusion of g-C₃N₄. Moreover, the optical susceptibility for these nanocomposite films increased as the content of g-C₃N₄ changed from 0.0 to 1.0 wt%. Finally, the values of the nonlinear refractive index showed improvement with the increased percentage of g-C₃N₄. When g-C₃N₄ was added up to 1.0 wt%, the DC conductivity improved from 4.21 × 10^-8 to 1.78 × 10^-6 S/cm. The outcomes of this study prove the suitable application of PVC/PVP/g-C₃N₄ in optoelectronic fiber sensors.