Submicrocubes and highly oriented assemblies of MnCO3 synthesized by ultrasound agitation method and their thermal transformation to nanoporous Mn2O3

MnCO3 submicrocubes and highly oriented MnCO3 nanocrystal assemblies with an ellipsoidal morphology have been successfully prepared by an ultrasonic solution approach. The effect of surfactants of sodium dodecylsulfate (SDS) and aerosol OT (AOT) on the morphology of MnCO3 was investigated. Highly oriented ellipsoidal assemblies composed of similar to 5 nm MnCO3 nanocrystals with porous nanostructures were prepared in the presence of SDS. Both sonochemical irradiation and surfactant play an important role in the formation of these highly oriented assemblies. Nanoporous Mn2O3 was obtained by thermal treatment of MnCO3 at 600 degrees C in air. The shape of MnCO3 was sustained after thermal transformation to form nanoporous Mn2O3. The products were characterized by X-ray powder diffraction, transmission electron microscopy, selected-area electron diffraction, field emission scanning electron microscopy, thermogravimetric analysis and differential scanning calorimetric analysis. (C) 2006 Elsevier B.V. All rights reserved.