Iron oxide nanopropellers prepared by a low-temperature solution approach

The alpha-Fe2O3 (hematite) nanopropellers were synthesized via a low-temperature solution-based method using FeCl2 as a precursor in the presence of urea and glycine hydrochloride. The formation of alpha-Fe2O3 nanopropellers is strongly depended on the addition of glycine hydrochloride, which serves as a pH modulator and affects the oxidation rate of Fe2+. The structural evolution of the propeller-structured hematite was found to follow dissolution and recrystallization processes. For the structural conformation, each nanopropeller presents a hexagonal central column closed by six equivalent surfaces of {(1) over bar 100} and the six arrays of the nanopropeller structure are a result of growth along +/-[(1) over bar 100], +/-[(1) over bar 010], and +/-[0 (1) over bar 10]. Preliminary results show that the magnetic maghemite (gamma-Fe2O3) nanopropellers could also be prepared by a reduction and reoxidation process from the alpha-Fe2O3 ( hematite) nanopropeller precursors.