Facile synthesis of vaterite core-shell microspheres

Vaterite core-shell microspheres composed of core-nanoparticles and shell-hexagonal nanoplates are synthesized by precipitation route assisted by poly(styrene sulfonic acid) sodium salt (PSS). The as-prepared products are characterized by XRD and SEM. With the addition of PSS, the crystal phase of calcium carbonate is transferred from calcite to vaterite. The growth process of vaterite microspheres is investigated by SEM. It is supposed that the core-shell structured microspheres with the nanoparticles in core and the hexagonal plates at the outer layer are attributed to the adsorption of PSS, ammonia and the re-crystallization of the nanoparticles.