Synthesis and formation mechanism of hematite hollow microspheres by a one-pot templateless surfactant-free hydrothermal process

Hollow microspheres of hematite (alpha-Fe2O3) were prepared by a simple hydrothermal treatment of fibrous ammonium sulphate hexahydrate ((NH4)(2)Fe(SO4)(2)center dot 6H(2)O) aqueous solution without any surfactant and additives at 180-200 degrees C. The products were characterized by XRD, FE-SEM and TEM. The results show that alpha-Fe2O3 hollow microspheres are about 1 mu m in diameters and are composed of alpha-Fe2O3 nanoparticles with a diameter range from 50 mm to 150 nm. The effects of reaction parameters such as reaction time, temperature and [(NH4)(2)Fe(SO4)(2)center dot 6H(2)O] on the morphology of the final product were investigation A potential formation mechanism of alpha-Fe2O3 hollow microspheres was also proposed, where the in mediate, urchin-like goethite, served as a sacrificial template for the formation of hollow structure. reaction parameters-depended morphologies of the final products consisted well with the proper formation mechanism. (C) 2009 Elsevier B.V. All rights reserved.