One-step and low-temperature synthesis of monetite nanoparticles in an all-in-one system (reactant, solvent, and template) based on calcium chloride-choline chloride deep eutectic medium

Abstract Monetite nanoparticles were synthesized via a facile and sustainable method using deep eutectic medium based on CaCl 2 ·6H 2 O-choline chloride to act as solvent, reactant and template. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). Analysis data revealed the formation of CaHPO 4 nanoparticles crystalized in anorthic structure with spherical morphology, mean particle size of 65 nm, and high elemental-structural purity. The results suggested the ternary role of the eutectic system in synthesis of monetite nanoparticles providing the synthesis medium, calcium-active reaction sites, and electrosteric stabilization by which the deep eutectic system can control the particle growth and agglomeration of monetite.