Hollow microellipsoid lithium silicate with mesoporosity and its formation mechanism

Lithium silicate is an important sorbent to capture CO2. Herein, hollow microellipsoids of lithium silicate with mesoporosity were prepared by a hydrothermal method using Na-montmorillonite and lithium hydrate as raw materials. X-ray diffraction, scanning electron microscope and transmission electron microscope analysis show that the crystal phase of the products is composed of lithium silicate and the particle morphology of the sample is hollow microellipsoid at around 600 nm. Furthermore, the wall of the microellipsoid is constituted of mesopores and nanoparticles with a size range within 20 to 40 nm. The specific area and aperture of the samples measured by Brunauer-Emmett-Teller method is 32.3 m2•g−1 and 17.1 nm, respectively. Finally, a formation mechanism of the hollow microellipsoid was proposed to guide further exploration.