Waste expanded polystyrene/zinc ferrite nanoparticles films: degradation by visible light photocatalysis and use in composites with rice husk reinforcement

A waste-expanded polystyrene (PSw) film was developed by incorporating zinc ferrite photocatalytic nanoparticles, synthesized through a simple green method. The nanoparticles were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the films were examined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Three sets of polystyrene (PS) film samples were prepared: pure PS (PSw), PS with iron and zinc nanoparticles (PSw-ZnO+FeO), and PS with zinc ferrite (PSw/ZnFe₂O₄). After 40 days of sunlight exposure, mass loss varied significantly among them. The PSw/ZnFe₂O₄ films degraded 3.7 times faster than pure PS, with the highest reduction reaching 14.08%, indicating the strong influence of zinc ferrite nanoparticles on degradation. The tensile strength of the samples was measured according to ISO-527–4:2023. Tensile tests revealed that sample B3 with rice husk reinforcement resisted three times more tension before breaking compared to virgin expanded polystyrene with a density of 120 g/L. These findings demonstrate the potential of PSw/ZnFe₂O₄ composites reinforced with rice husk as materials with improved mechanical strength and reduced environmental persistence compared to conventional expanded polystyrene.