Morphology-controlled hydrothermal synthesis of MnCO{sub 3} hierarchical superstructures with Schiff base as stabilizer

• Published in: Materials research bulletin Vol. 46; no. 11
• Main Authors: Hu, He, Xu, Jie-yan, Yang, Hong, Liang, Jie, Yang, Shiping, Wu, Huixia
• Format: Journal Article
• Language: English
• Published: United States 15.11.2011
• Subjects: CARBON DIOXIDE; CRYSTAL STRUCTURE; CRYSTALS; ETHANOL; HYDROTHERMAL SYNTHESIS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ION SOURCES; MANGANESE CARBONATES; MANGANESE IONS; MICROSTRUCTURE; MORPHOLOGY; NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; PYROLYSIS; SCHIFF BASES
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/J.MATERRESBULL.2011.07.028

Graphical abstract: MnCO3 microcrystals with hierarchical superstructures were synthesized by using the CO2 in atmosphere as carbonate ions source and Schiff base as shape guiding-agent in water/ethanol system under hydrothermal condition. Highlights: {yields} The most interesting in this work is the use of the greenhouse gases CO{sub 2} in atmosphere as carbonate ions source to precipitate with Mn{sup 2+} for producing MnCO{sub 3} crystals. {yields} This work is the first report related to the small organic molecule Schiff base as shape guiding-agent to produce different MnCO{sub 3} hierarchical superstructures. {yields} We are controllable synthesis of the MnCO{sub 3} hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like microcrystals. {yields} The as-prepared MnCO{sub 3} could be used precursor to fabricate the Mn{sub 2}O{sub 3} hierarchical superstructures after thermal decomposition at high temperature. -- Abstract: MnCO{sub 3} with hierarchical superstructures such as chrysanthemum, straw-bundle, dumbbell and sphere-like were synthesized in water/ethanol system under environment-friendly hydrothermal condition. In the synthesis process, the CO{sub 2} in atmosphere was used as the source of carbonate ions and Schiff base was used as shape guiding-agent. The different superstructures of MnCO{sub 3} could be obtained by controlling the hydrothermal temperature, the molar ratio of manganous ions to the Schiff base, or the volume ratio of water to ethanol. A tentative growth mechanism for the generation of MnCO{sub 3} superstructures was proposed based on the rod-dumbbell-sphere model. Furthermore, the MnCO{sub 3} as precursor could be further successfully transferred to Mn{sub 2}O{sub 3} microstructure after heating in the atmosphere at 500 {sup o}C, and the morphology of the Mn{sub 2}O{sub 3} was directly determined by that of the MnCO{sub 3} precursor.