Hydrothermal synthesis of MnCO3 nanorods and their thermal transformation into Mn2O3 and Mn3O4 nanorods with single crystalline structure

MnCO3 nanorods with diameters of 50-150nm and lengths of about 1-2 mu m have been prepared for the first time by a facile hydrothermal method. Mn2O3 and Mn3O4 nanorods were obtained via the heat-treatment of the MnCO3 nanorods in air and nitrogen atmosphere, respectively. The morphology and structure of the as-synthesized MnCO3, Mn2O3 and Mn3O4 nanorods were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and selected area electron diffraction. It was found that the MnCO3 nanorods are single-crystalline, and their morphology and single-crystalline characteristic can be sustained after thermal transformation into Mn2O3 and Mn3O4. The corresponding growth directions for MnCO3, Mn2O3 and Mn3O4 nanorods were [2 1 4], [1 0 0] and [1 1 2], respectively. When applied as anode materials for lithium ion batteries, the Mn2O3 and Mn3O4 nanorods exhibited a reversible lithium storage capacity of 998 and 1050 mAh/g, respectively, in the first cycles. (C) 2011 Elsevier B.V. All rights reserved.