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-Fe 2 O 3 ), maghemite (γ-Fe 2 O 3 ), magnetite (Fe 3 O 4 ) and wustite (FeO) were synthesized via solid-state thermolysis of a chiral, 3D anhydrous potassium tris(oxalato)ferrate(III) (K 3 [Fe(C 2 O 4 ) 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.