Mechanism for the formation of magnetite iron oxide nanostructures by Ficus carica dried fruit extract using green synthesis method

Abstract

The green synthesis of iron oxide nanoparticles is a convenient, inexpensive, rapid, and ecofriendly method compared to traditional synthesis methods. Magnetic iron oxide nanoparticles with appropriate nanosized exhibit many interesting properties that can be exploited in a variety of biomedical applications. In this regard, we have synthesized magnetite iron oxide (Fe3O4) nanostructures from ferric chloride solution in aqueous extracts of Ficus carica dried fruit. Nanostructures were characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometry (EDX), and ultraviolet–visible spectrophotometer (UV–Vis). The XRD study revealed the magnetite structure. FE-SEM results showed various nanoshapes (nanoparticles, nanowires and nanoellipsoids) at different volumetric ratios (1:0.5, 1:0.75, and 1:1) of ferric chloride and extract solution, respectively. At higher concentration of solute, the process of agglomeration started, and the amorphous film is formed. UV–Vis spectroscopy showed the absorption peaks at 220 nm and 302 nm. Chemical composition analysis confirmed the presence of magnetite. Mechanism for the formation of various nanostructures was discussed on the basis of classical nucleation theory. The smaller critical nuclei favor the formation of spherical magnetite nanoparticles at lower concentration. By increasing the concentration, size of the critical nuclei increases resulting in the formation of amorphous film.