Green Synthesis and Photocatalytic Evaluation of ZnO-Fe3O4 Nanocomposites for the Degradation of Methylene Blue Dye under Solar Irradiation

Abstract

The discharge of synthetic dyes into industrial effluents represents a significant environmental concern due to their high chemical stability and persistence in aquatic environments. Among these pollutants, methylene blue (MB) is widely used and may cause harmful effects on ecosystems and human health. In this study, ZnO and Fe3O4 nanoparticles were synthesized through green routes using okra and potato peel extracts, followed by the preparation of ZnO-Fe3O4 nanocomposites by a mechanical mixing method. The materials were characterized by XRD, SEM/EDS, FTIR, and UV-Vis DRS. Photocatalytic tests under solar irradiation showed high degradation efficiencies of MB, reaching 95.63% for ZnO, 95.92% for 4ZnO-1Fe3O4, 91.66% for 1ZnO-1Fe3O4, and 53.63% for Fe3O4. The results indicate that the incorporation of Fe3O4 into ZnO contributes to the photocatalytic performance of the nanocomposites and highlights their potential for the treatment of dye-contaminated wastewater.