GREEN SYNTHESIS OF NANO-ZERO-VALENT IRON USING CLEISTOCALYX OPERCULATUS EXTRACT FOR EFFICIENT RHODAMINE B DEGRADATION

In this study, nano-zero-valent iron (nZVI) was successfully synthesized via a green method using Cleistocalyx operculatus leaf extract as a natural reducing and capping agent. The synthesized nZVI was characterized by XRD, SEM-EDS, FT-IR, and BET. The XRD pattern confirmed the formation of crystalline α-Fe⁰, while SEM images revealed spherical aggregates in the 50-100 nm size range. FT-IR analysis identified organic functional groups from the plant extract on the nanoparticle surface, indicating bio-capping. BET analysis showed a specific surface area of 67.484 m2/g with a mixed micro-mesoporous structure. Batch experiments revealed that while nZVI alone primarily adsorbed Rhodamine B (RhB) and H₂O₂ alone exhibited limited oxidation, the combined nZVI/H₂O₂ system achieved nearly complete decolorization within 50 min. The enhanced efficiency was attributed to a heterogeneous Fenton-like process generating highly reactive ·OH radicals. These findings demonstrate that Cleistocalyx operculatus-mediated nZVI offers a sustainable and effective approach for the removal of organic dyes from wastewater, highlighting its potential in advanced water treatment applications.