Green Nanotechnology for Water Remediation: Eco-Friendly Synthesis of Zinc Oxide Nanoparticles and Methylene Blue Degradation Kinetics

In this study, zinc oxide nanoparticles (ZnO-NPs) were synthesized using eco-friendly matrices, including starch (S), soy lecithin (L), and polyvinylpyrrolidone (PVP). The ZnO-NPs were obtained from different matrices: ZnO-S, ZnO-L, and ZnO-PVP were characterized through UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Zeta potential (ξ), and dynamic light scattering (DLS). TEM analysis revealed quasi-spherical ZnO-NPs, and XRD confirmed the crystalline structure and estimated an average nanoparticle size of around 22 nm, consistent with the TEM results. The photocatalytic performance of the ZnO-NPs was evaluated in the degradation of methylene blue (MB) under both UV and sunlight. ZnO-L demonstrated the highest efficiency, degrading up to 97.68% of MB. Kinetic studies indicated that the photodegradation has a reaction order of 1.4, and the reaction rates rise as the concentrations of MB increase. This study highlights the potential of green nanotechnology in water remediation, providing a sustainable approach to address environmental dye pollution. The results suggest that ZnO-L synthesized using the matrix of soy lecithin, an industrial byproduct, offers an efficient and eco-friendly alternative for wastewater treatment. The results demonstrate the potential of ZnO nanoparticles as efficient catalysts for the solar photodegradation of MB, offering an environmentally friendly solution to water pollution.