Synthesis, structural, optical and morphological characterization ofhematite through the precipitation method: Effect of varying thenature of the base

International audienceIron oxide (a-Fe2O3) nanoparticles were synthesized using the precipitation synthesis method focusingonly on (FeCl3, 6H2O), NaOH, KOH and NH4OH as raw materials. The impact of varying the nature of thebase on the crystalline phase, size and morphology of a-Fe2O3 products was explored. XRD spectrarevealed that samples crystallize in the rhombohedral (hexagonal) system at 800 C.The TransmissionElectron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to detect themorphology of synthesized nanoparticles and specify their sizes.However, the Fourier Transform Infra-Red (FT-IR) spectroscopy has permitted the observation of vibrationband Fe-O. Raman spectroscopy was used not only to prove that we have synthesized hematitebut also to identify their phonon modes. The Thermo Gravimetric Analysis (TGA) findings allow thethermal cycle determination of samples whereas Differential Thermal Analysis (DTA) findings allow thephase transition temperature identification. Besides, the optical investigation revealed that samples havean optical gap of about 2.1 eV. Findings highlight that the nature of the agent precipitant plays a significantrole in the morphology of the products and the formation of the crystalline phase. Hematitesynthesis with the base NH4OH brought about much stronger, sharper and wider diffraction peaks of a-Fe2O3. The morphology of samples are spherical with a size of about 61 nm while the size of thenanoparticles of hematite which we have synthesized with NaOH and KOH is respectively of the order of82 and 79 nm