Seeded Growth Route to Noble Calcium Carbonate Nanocrystal

<div><p>A solution-phase route has been considered as the most promising route to synthesize noble nanostructures. A majority of their synthesis approaches of calcium carbonate (CaCO₃) are based on either using fungi or the CO₂ bubbling methods. Here, we approached the preparation of nano-precipitated calcium carbonate single crystal from <i>salmacis sphaeroides</i> in the presence of zwitterionic or cationic biosurfactants without external source of CO₂. The calcium carbonate crystals were rhombohedron structure and regularly shaped with side dimension ranging from 33–41 nm. The high degree of morphological control of CaCO₃ nanocrystals suggested that surfactants are capable of strongly interacting with the CaCO₃ surface and control the nucleation and growth direction of calcium carbonate nanocrystals. Finally, the mechanism of formation of nanocrystals in light of proposed routes was also discussed.</p>