The Precipitation of Monodispersed α-Iron(III) Oxide Particles from Iron(III) Chloride–Glycine System in Aqueous and 2-Propanol/Water Media

Monodispersed α-iron(III) oxide (hematite) particles were prepared by aging iron(III) chloride solutions in the presence of glycine at elevated temperatures, 98–100 °C. An aqueous solution of glycinatoiron (III) complex directly gave monodispersed double spheres of hematite, ≈4 μm in size, under the specified conditions, for example, 2.0×10−2 mol dm−3 FeCl3, 0.60 mol dm−3 glycine, and 0.46 mol dm−3 HCl for 96 h. The hematite particles grew up through the polynuclear layers mechanism. By the forced hydrolysis in 2-propanol/water mixed solution of 30% by volume, monodispersed cuboidal hematite particles, 0.06–0.43 μm in size, were also obtained through the conversion of β-iron(III) hydroxide oxide previously deposited. The nucleation rate was markedly affected by acidity at the latter case. The formation processes of these monodispersed hematite particles are discussed.