Antibacterial and photocatalytic performance of eggshell-derived CaF2-mortar cement composites

Abstract

Eggshells have been reported to generate huge tons of waste globally. Various uses of eggshells are widely reported in the literature in terms of dietary supplements, filler in bones, etc. through their extraction as a Ca source. In this study, 900 °C was adopted for CaO and CaCO₃ formation from the eggshell. This heated eggshell powder was further reacted with hydrofluoric acid (HF) aqueous solution to prepare CaF₂. This CaF₂ was first tested for antibacterial activity against E. coli, which indicated that CaF₂ derived from eggshell was effective as an antibacterial. By incorporating CaF₂ (5%, 10%, and 15% by wt.) into cement mortar, it was found that the mortar composites showed antibacterial activity. Furthermore, photocatalytic activity was monitored using the degradation of the dye solution. All the mortar composites have demonstrated photocatalytic properties.