Annealing Temperature Effect on Structural, Magnetic Properties and Methyl Green Degradation of Fe2O3 Nanostructures

Abstract

In this paper, hematite (α-Fe2O3) nanoparticles were prepared at two different temperatures (500 and 600 °C) by one-step direct thermal decomposition of Fe(NO3)2·6H2O at the presence of urea (1:1 weight ratio). The products were named as Fe-1 and Fe-2 and characterized by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM). The photocatalytic activities of the products were studied by degradation of methyl green (MG) dye in aqueous solution at room temperature. According to the XRD results, the average size of crystallites Fe-2 is 110 nm. The applied method is fast, facile and does not use any solvents. The magnetic properties show that the saturation magnetization of Fe-2 (≈ 0.9 emu/g) is higher than that of Fe-1 (≈ 0.6 emu/g) which confirms the higher purity of α-phase of Fe-2. In addition, the products were used for the degradation of MG from aqueous solution. The influence of various parameters such as contact time and mass of the α-Fe2O3 nanoparticles has been studied. The photocatalytic results predict that the as-prepared hematite (α-Fe2O3) nanoparticles have potential to be used as an efficient degradation agent of MG and other cationic dyes.