Green Synthesis of Fe/Graphene Nanocomposite Using Cleistocalyx Operculatus Leaf Extract As a Reducing Agent: Removal of Pollutants (rhb Dye and Cr6+ Ions) in Aqueous Media

Industrial wastewater contains many compounds that pollute the environment, which have a strong impact on humans and the ecosystem. Zero-valent iron nanoparticles (nZVI) are materials with the potential to treat many wastes released into the aquatic environment. nZVI was synthesized via a green method using Cleistocalyx operculatus (CO) leaf extract as a reducing agent. Among them, graphene nanoplatelets (GNPs) were used as support materials to enhance the reduction capacity and stability of nZVI. The morphology, structure, and crystallinity of the nZVI@GNPs nanocomposite were demonstrated through scanning electron microscopy (SEM), X-ray diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDS), and Fourier Transform Infrared (FTIR). Zero-valent iron nanoparticles following an optimized process for spherical particles with particle sizes ranging from 30-100 nm, uniformly distributed on the surface of GNPs. The removal performance of RhB and Chromium (VI) ions by the nZVI@GNPs composite was evaluated through Ultraviolet-Visible Spectroscopy (UV-Vis). The results show that nZVI/GNPs can remove RhB and Cr6+ more than 98 % after 30 minutes of treatment. The affecting factors on the treatment process, such as pH, reaction time, and amount of material, were also studied.