Morphology control synthesis of nano rods and nano ovals CaCO₃ particle systems

Abstract

Uniform fine particles of CaCO₃ in nano rod and nano oval morphology were synthesized by carbonation and controlled precipitation methods. For this, commercially available cheap source of quicklime was used as a starting reactant against different precipitants, i.e., CO₂, Na₂CO₃ and (NH₄)₂CO₃. The effect of precipitating agent and various other experimental conditions on particle size and shape was systematically studied. The reaction parameters were extensively optimized for the generation of novel morphologies of CaCO₃ ultrafine particle systems in a reproducible manner. The synthesized material was characterized by SEM, X-ray diffraction (XRD), FT-IR, and TGA/DTA techniques. Cubic and spherical shape particles were produced by using Na₂CO₃ and (NH₄)₂CO₃ respectively as a precipitating agents. Agitation of the reaction mixture by sonication and mechanical stirring affected the particle uniformity. Furthermore, unique novel morphologies of CaCO₃ particles in rod and oval shapes were synthesized from carbonation of Ca(OH)₂ at low temperature with a flow rate of 0.6 L/min in the absence and presence of K₂SO₄ respectively. The XRD results showed single phase formation of calcite for both morphologies, while the preferred orientation of XRD peak was observed at (104) plane. The calculated activation energy showed thermal stability of the synthesized oval shape CaCO₃ particles over the rod shape particle morphology.

Graphical Abstract

Keywords:

• Nanoparticle
• calcite
• calcium carbonate
• carbonation

Additional information

Funding

The authors acknowledge the National Center of Excellence in Physical Chemistry, University of Peshawar, for facilitating this research work. Financial support from the Higher Education Commission (HEC), Islamabad, Pakistan, is gratefully acknowledged under the Project No. 20-3588.