The influence of co-precipitation and green synthesis of holy basil leaves, blue pea, and oolong tea on the properties of iron oxide nanoparticles

Abstract

Iron oxide nanoparticles (IONPs) are classified according to their size between 1 and 100 nanometers. In this study, IONPs were synthesized by two methods, conventional method which is co-precipitation and green synthesis method using plant extracts. Green synthesis of nanoparticles is environmental friendly, good value and non-toxic. Three different types of plant extracts were used including holy basil, blue pea, and oolong tea which act as the reducing agent. The plant extracts were mixed separately with iron chloride solution (solution of iron II 4-hydrate & iron III 9-hydrate). The morphology and crystallinity of IONPs were studied using XRD, SEM, and UV-Vis test. The IONPs had the band gap energy with range from 1.4 eV to 2.00 eV. In addition, significant peaks of β-Fe₂O₃ (IONPs) were detected in XRD. Under SEM observation, irregular spherical shapes of iron oxide nanoparticles were seen. The particles were big and agglomerated. The agglomeration of IONPs could be caused by inhomogeneous stirring of iron chloride solution and long calcination time.