Iron oxide nanoparticles synthesized by controlled bio-precipitation using leaf extract of Garlic Vine (Mansoa alliacea)

Iron (III) oxide nanoparticles were synthesized through green chemistry by the controlled reduction of hepta hydrous iron sulphate using the leaf extract of Garlic Vine. The crystalline phase of trivalent iron embedded in the primitive lattice of hexagonal β-Fe₂O₃ was obtained under the space group P3 (143). The scattered lines and considerably broadened peaks in the x-ray diffraction pattern indicate that the samples formed are crystallites of nano regime rather than bulk or amorphous in nature. Further, the size and the microstrain of the nanocrystallites were estimated through Hall Williamson analysis. The abundance of elemental iron present in the sample was estimated through Atomic Absorption Spectroscopy, whilst the UV visible analysis and FT-IR measurements, in accordance with XRD result, endorsed the formation of iron (III) oxide nanocrystals with iron predominantly occupying the octahedral sites. The band gap energy (2.84 eV) corresponds to the best fit is found to be for indirect allowed semiconducting transition between valance and conduction bands. Further, the TGA measurements were performed to identify the presence of capped polymer over the surface of nanoparticles, the organic decomposition temperature and phase transformation of meta-stable β-Fe₂O₃ to stable α-Fe₂O₃ at temperature above 500 °C.