Facile green synthesis of iron oxide nanoparticles via solid-state thermolysis of a chiral, 3D anhydrous potassium tris(oxalato)ferrate(III) precursor

Abstract

The iron oxide nanoparticles hematite (α-Fe2O3), maghemite (γ-Fe2O3), magnetite (Fe3O4) and wüstite (FeO) were synthesized via solid-state thermolysis of a chiral, 3D anhydrous potassium tris(oxalato)ferrate(III) (K3[Fe(C2O4)3]) precursor. A controlled heat treatment for the precursor material in air forms these four iron oxide polymorphs. Powder X-ray diffraction (XRD) and Raman spectroscopy were used to identify the different iron oxide nanoparticle polymorphs. The morphology of the obtained iron oxide nanoparticles was determined using a field emission scanning electron microscope (FE-SEM). The magnetic properties of the as-synthesized iron oxide nanoparticles was studied using a superconducting quantum interference device (SQUID), and the results indicated that they are weakly ferromagnetic, ferrimagnetic and paramagnetic in nature.