Enhanced refractive index and nonlinear optical susceptibility in PVDF-ZrO₂/g-C₃N₄ based nanocomposites for NLO applications

This paper reports on the fabrication and characterization of PVDF/ZrO₂/g-C₃N₄ polymer nanocomposites for enhanced optical properties. The composite films were prepared via a solution casting method and their structural, morphological, and optical properties were investigated using various techniques like XRD, FTIR, SEM, and UV–Vis spectroscopy. XRD analysis revealed ZrO₂ with tetragonal crystal structure and confirmed the interaction with PVDF polymer network. SEM analysis revealed changes in the spherulitic pattern of PVDF upon nanofiller addition, suggesting interactions at the microscopic level. The inclusion of nanofillers decreased the transmittance of the films, indicating increased light absorption within the material. The optical band gap of the composites was found to depend on the ZrO₂/g-C₃N₄ content. The refractive index of the composites increased with increasing nanofiller loading, enabling control over light propagation. Finally, this work demonstrates the effectiveness of incorporating ZrO₂/g-C₃N₄ nanofillers into PVDF to achieve advanced optical properties with potential applications in photonics, sensors, and optoelectronic devices.