GREEN SYNTHESIS, SPECTROSCOPIC ANALYSIS AND STABILISATION ENERGY OF IRON OXIDE NANOPARTICLES FROM AQUEOUS Ziziphus LEAF EXTRACT

Abstract

Ziziphus mauritiana (ZM) leaf extract was used to synthesize FeO nanoparticles (NPs) and characterised by UV-visible, FTIR, XRD, and SEM. From this study the phytochemical constituents present in the aqueous Ziziphus extract were identified to include phenols, saponins, flavonoids and tannins which both serve as reducing, capping and stabilising agents. The presence of these phytochemicals was confirmed from laboratory tests and infrared spectroscopy. A wavelength of 400 nm was found to correspond to the surface plasmon resonance and used to determine the stabilisation energy of the FeO NPs and found to be 299 kJ/mol. More so, a broad peak was observed at 3426 cm-1 for the leave extract and 3386 cm-1 for the FeO NPs corresponding to O-H stretching vibration probably from alcohols, flavonoids, and phenols. A significant IR peak observed at 536 cm-1 in the FeO NPs spectrum but absent from that of the plant extract, was assigned to Fe-O stretching vibration and serves as a strong evidence for the formation of the nanoparticles. The XRD analysis revealed facecentred cubic morphology with an average crystal size of 36.3 nm calculated by Debye – Scherrer equation and the SEM analysis showed the nanoparticles to be spherical in shape.
The synthesized NPs were found to possess significant antimicrobial activity against S. typhi (18 µg/L), E. coli (15 µg/L) S. aureus (16 µg/L0 and S. pneumonia (16 µg/L) by welldiffusion method. The inhibiting activity of the synthesized NPs increased with increase in concentration of the nanoparticles.