Shape-Controlled Synthesis of Metal Carbonate Nanostructure via Ionic Liquid-Assisted Hydrothermal Route: The Case of Manganese Carbonate

The MnCO3 hollow microspheres and nanocubes have been successfully synthesized via an ionic liquid-assisted hydrothermal synthetic method. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). Our experimental results demonstrate that the MnCO3 hollow microspheres are obtained by self-assembly under the driving force of Ostwald ripening process. Moreover, we found that the sizes and morphologies or the crystals depended on the concentration of the ionic liquid, and we obtained the MnCO3 nanocubes formed by ordered aggregation of nanoplates with high concentration of [bmim][Cl]. The effects of [bmim][Cl] on the formation of the MnCO3 have been investigated systematically. This method is expected to be a useful technique to prepare other metal carbonates for controlling the diverse shapes and sizes.