Microemulsion-made Magnesium Carbonate Hollow Nanospheres

Abstract

Magnesium carbonate (MgCO3) hollow nanospheres and their structural and thermal properties are presented. The hollow nanospheres are prepared via a microemulsion-based synthesis using dibutylmagnesium(II) and CO2 as the starting materials. Size, structure, and composition of the as-prepared MgCO3 hollow nanospheres are comprehensively validated by different analytical methods (SEM, STEM, TEM, XRD, FT-IR, TG). Accordingly, they exhibit an outer diameter of 35 ± 9 nm, an inner cavity size of 17 ± 5 nm, and a wall thickness of 9 ± 3 nm. Furthermore, the as-prepared MgCO3 hollow nanospheres exhibit a specific surface area of 90 m2·g–1 and pore radii with a maximum at 10–15 nm that both reflect the inner cavity. By sintering (600 °C), the MgCO3 hollow nanospheres can be converted to MgO, which does not show a hollow-sphere structure but which still exhibits a high specific surface area (110 m2·g–1). The synthesis of MgCO3 hollow nanospheres is generally shown for the first time.