Controlled Oxidant-to-Fuel Ratios for Synthesis of Inorganic Hematite Pigment (-Fe₂O₃) Using Solution Combustion Method with 6-Aminohexanoic Acid as Fuel

In this study, alpha-Fe2O3 was synthesized by solution combustion method using 6-aminohexanoic acid (AH) as a fuel and with different oxidizer-to-fuel ratios (Phi) of 0.6, 0.8, 1.0, 1.2, and 1.4. The as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR), and UV-Vis spectroscopy. The results showed that the Phi ratio played a crucial role in determining the crystallinity and purity of the powders of alpha-Fe2O3. The alpha-Fe2O3 powder synthesized at an Phi ratio of 0.6 exhibited phase purity of hematite. This study demonstrates the importance of controlling the Phi ratio in the synthesis of alpha-Fe2O3 which could be used as an inorganic pigment in paints.