Engineering Recycled Polystyrene with SnO2 Nanofiller for Sustainable Optoelectronic Applications

Polymer nanocomposites have emerged as promising materials for next-generation optoelectronic technologies, offering a unique synergy between the tunable properties of polymers and the multifunctionality of inorganic nanoparticles. In this study, we explore the development of sustainable nanocomposite films by incorporating tin dioxide (SnO2) nanoparticles into recycled polystyrene (rPS), aiming to enhance the optical and electronic properties of the base polymer. Nanocomposite films were fabricated via a solution casting technique with varying SnO2 loadings (1–7 wt%), followed by comprehensive characterization using X-ray diffraction (XRD), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-visible spectroscopy. This analysis confirmed successful integration and uniform dispersion of SnO2 nanoparticles at lower concentrations, leading to significant modifications in the optical characteristics of rPS. XRD data showed tetragonal crystal structure of SnO2. The addition of SnO2 decreased the intensity of both 1000 cm−1 Raman peak and 700 cm−1 FTIR peak of rPS. Notably, the nanocomposites exhibited enhanced light absorption, increased refractive index, and a notable reduction in the optical band gap from 3.397 eV in recycled polystyrene (rPS) to 3.095 eV at 7 wt% SnO2. The static refractive index (no) enhanced from 3.674 to 4.925 upon increasing SnO2 content. Additionally, third-order nonlinear optical susceptibility χ(3) and nonlinear refractive index (n₂) values increased with SnO2 content, underscoring the material’s potential for photonic applications. The findings suggest that rPS/SnO2 nanocomposites hold promise for developing sustainable materials for optoelectronic devices.