Flexible and innovative PVA/ZrO2/g-C3N4/CNT nanocomposites film for optoelectronic applications

This study successfully prepared polyvinyl alcohol (PVA) polymer films doped with ZrO 2 /(g-C 3 N 4 /CNT) nanofillers using the solution casting technique. The crystal structure of the nanocomposite films was characterized by X-ray diffraction (XRD), revealing the semi-crystalline nature of PVA and an average ZrO 2 crystallite size of 13.17 nm. Fourier-transform infrared (FTIR) spectroscopy confirmed the chemical composition and functional groups present in the nanocomposites. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed uniform dispersion of the nanofillers without noticeable phase separation, with EDX confirming the successful incorporation of ZrO 2 , g-C 3 N 4 , and CNT into the PVA matrix. X-ray photoelectron spectroscopy (XPS) further validated the elemental composition and chemical states, indicating the presence of carbon, oxygen, nitrogen, and zirconium. Optical analysis demonstrated that increasing ZrO 2 /(g-C 3 N 4 /CNT) content reduced the direct and indirect band gaps from 5.41 eV to 5.25 eV and from 5.18 eV to 4.92 eV, respectively. In addition, the single-oscillator energy ( E 0 ) and dispersion energy ( E d ) increased, while the static refractive index (n 0 ) decreased. Improvements were also observed in linear optical susceptibility (χ (1) ) and third-order nonlinear optical susceptibility (χ (3) ), enhancing the polarizability of the polymer molecules. These results indicate that PVA films doped with ZrO 2 /(g-C 3 N 4 /CNT) hold promise for optoelectronic applications due to their enhanced optical properties. • PVA/ZrO 2 /(g-C 3 N 4 /CNT) nanocomposite films were successfully prepared using the solution casting technique. • Structural characterization confirmed the uniform dispersion of nanofillers, with no macroscopic phase separation observed. • Increasing nanofiller content reduced the optical band gaps and enhanced single-oscillator and dispersion energies. • XPS and EDX analyses validated the successful incorporation of ZrO 2 , g-C 3 N 4 , and CNT into the PVA polymer matrix. • Improved linear and third-order nonlinear optical susceptibilities suggest the potential for optoelectronic applications.