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

Abstract

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-NPswere obtained from different matrices: ZnO-S, ZnO-L, and ZnOPVP were characterized through UV−visible spectroscopy, X-raydiffraction (XRD), transmission electron microscopy (TEM),Fourier transform infrared spectroscopy (FT-IR), Zeta potential(ξ), and dynamic light scattering (DLS). TEM analysis revealedquasi-spherical ZnO-NPs, and XRD confirmed the crystallinestructure and estimated an average nanoparticle size of around 22nm, consistent with the TEM results. The photocatalytic performance of the ZnO-NPs was evaluated in the degradation ofmethylene blue (MB) under both UV and sunlight. ZnO-Ldemonstrated the highest efficiency, degrading up to 97.68% of MB. Kinetic studies indicated that the photodegradation has areaction order of 1.4, and the reaction rates rise as the concentrations of MB increase. This study highlights the potential of greennanotechnology in water remediation, providing a sustainable approach to address environmental dye pollution. The results suggestthat ZnO-L synthesized using the matrix of soy lecithin, an industrial byproduct, offers an efficient and eco-friendly alternative forwastewater treatment. The results demonstrate the potential of ZnO nanoparticles as efficient catalysts for the solarphotodegradation of MB, offering an environmentally friendly solution to water pollution.