Simple Hydrolysis Synthesis of Uniform Rice-Shaped β-FeOOH Nanocrystals and Their Transformation to α-Fe2O3 Microspheres

In the synthesis of nanostructure materials a specific emphasis has been focused on the control of shape and orientation of nanocrystals to obtain prerequisite properties of the materials. Nanorice is a new hybrid nanoparticle prolate geometry of nanoshells with reduced symmetry having new exciting optical behavior. Rice-shaped β-FeOOH nanocrystals have been synthesized by a simple hydrolysis chemical method using ferric aqueous solution and urea as surfactant. The successive calcination of β-FeOOH nanocrystals at 650°C results in the formation of the porous α-Fe2O3 (hematite) microspheres. The as-synthesized yield of β-FeOOH nanocrystals was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and optical spectroscopy. The successive transformation of rice-shaped β-FeOOH nanostructures into porous α-Fe2O3 (hematite) microspheres through calcination process was confirmed by XRD, SEM, and EDAX studies. The water contact angle of as-prepared α-Fe2O3 microspheres shows hydrophobic behavior of the material.