Synthesis of Tunable-Aspect-Ratio Calcite Nanoparticlesvia Mg 2+ Doping

Calcite nanoparticles are produced via CO2 gas bubbling in the Ca(OH)2 aqueous slurry and have been extensively used as filler materials for more than a century. However, the control of their morphology is not completely understood even though it is technologically relevant in the industry because detailed nanoscale investigations of their morphological changes during synthesis have only been recently conducted. In this study, c-axis-elongated calcite chain-like nanoparticles were synthesized via CO2 bubbling in a Ca(OH)2 slurry containing different doping amounts of Mg2+, which is a calcite crystal growth inhibitor. The precipitation of Mg-bearing calcite nanoclusters onto the crystal surface altered the dissolution–reprecipitation rate during synthesis. Hence, the morphology of the resulting 1D nanoparticles can be controlled by varying the Mg2+ doping amount.