Synthesis of Calcium Fluoride Nanoparticles From Waste Hexafluorisilicic Acid of Fertilizer Industry

The disposal of hexafluorosilicic acid (H
2
SiF
6
) poses a significant challenge due to its hazardous nature as a by-product of the agricultural industry. With the industry’s large-scale production, managing the disposal of the acid is a crucial concern. H
2
SiF
6
has harmful impacts on both human health and the environment. Additionally, the acid is corrosive to commonly used materials like glass and metals. Mesoporous silica nanoparticles (MSN’s) have been succesfully produced from hexafluorosilicic acid. In this study we present a process where the $\mathrm{NH}_{4}\mathrm{~F}$ solution available post synthesis of MSN’s has been used to sythesize calcium fluoride (CaF
2
) nanoparticles.The obtained CaF
2
nanoparticles were characterized using various analytical techniques such as X ray diffraction (XRD), scanning electron microscopy (SEM), and EDAX. The XRD pattern confirmed the formation of pure (CaF
2
) nanoparticles with an average particle size of $10\mathrm{~nm}$, while SEM images revealed their nearly spherical shape and well-dispersed nature. The findings of this study highlight a sustainable and simple method for the synthesis of CaF
2
nanoparticles with potential applications in various fields, including biomedicine, photonics, and catalysis.