Removal of Congo Red Using Iron-Based Nanoparticles Synthesized by Citrus Family Peel Extracts

Abstract Iron-based nanoparticles were synthesized without addition of any pH stabilizers, stabilizers and capping agent. The particles were prepared using lemon, tangerine, orange and grapefruit peel extracts. The optimum reaction parameters were determined with UV–Visible spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmittance electron microscopy (TEM) and Thermogravimetric analysis (TG/DTG) were used. XRD results identified binary formation of Fe3O4 and Fe2O3 with powder diffraction file numbers of “01-074-1910” and “03-065-0390”, respectively. According to morphological results, the smallest particle size range of 155–225 nm was observed in LP-Fe Np (iron-based nanoparticles synthesized by using lemon peel extract). UV-Vis indicated the iron nanoparticle formation in the range of 220–380 nm. The decomposition processes of the synthesized samples were occurred in multiple stages between 30 and 518°C. The smallest particles were measured at TP-Fe Np as 1.36–30.76 nm in TEM analyses. The adsorption of Congo red on the synthesized nanoparticles were also determined. The highest removal rate was obtained for the GP-Fe Np as 36.5%.