PVP-assisted synthesis of flower-like hematite microstructures composed of porous nanosheets

Novel flower-like hematite microstructures composed of many porous nanosheets were synthesized by a PVP-assisted process, and ferric chloride served as inexpensive and nontoxic iron source. The precursor was firstly prepared using ethylene glycol as solvent and urea as base media, and alpha-Fe2O3 flowers were subsequently obtained by thermal treatment of the precursor powder in oxygen atmosphere at 450 degrees C for 3 h. The phase purity and morphology of the samples were investigated by XRD, SEM, and TEM techniques. Such alpha-Fe2O3 flowers possessed an average size of 2-3 mu m and the thickness of assembled porous sheets was about 50 nm, and the shape was highly dependent on the dosage of PVP and reaction time, respectively. Magnetic measurement showed that the flower-like alpha-Fe2O3 hierarchical microstructures possessed ferromagnetic nature with magnetization value of 0.97 emu/g at the maximum magnetic field and a coercivity of 260 Oe, respectively .