RETRACTED ARTICLE: Photocatalytic degradation of methylene blue dye by iron oxide (α-Fe₂O₃) nanoparticles under visible irradiation

Iron oxide (α-Fe₂O₃) nanoparticles were precipitated from iron (III) chloride hexahydrate (FeCl₃·6H₂O) at the reaction temperature 80 °C for 3 h and were further calcinated at 600, 700, 750, 800 and 850 °C for 4 h. The effect of calcination temperature on the structural, morphological, optical, magnetic and photocatalytic activity was investigated. XRD data revealed a rhombohedral (hexagonal) structure with the space group R-3c in all samples. The calcination temperature was significantly influenced the particle size and morphological properties of hematite nanoparticles and the particle size was increased from 18 to 37 nm with the increased of the calcination temperature. The synthesized nanoparticles were roughly in spherical morphology was confirmed by TEM and SEM. FT-IR confirms the phase purity of the nanoparticles synthesized. Raman spectroscopy was used not only to prove that we have synthesized pure α-Fe₂O₃ but also to identify their phonon modes. The thermal behavior of compound was studied by using TGA/DTA results: the TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV and that this value varies as a function of the calcination temperature. The products exhibited the attractive magnetic properties with high saturation magnetization, which were examined by (VSM). The photocatalytic activities of the samples were studied based on the degradation of methylene blue as a model compound, where the results showed that hematite (α-Fe₂O₃) a good photocatalytic activity.