Eco-Friendly Photocatalyst Derived from Egg Shell Waste for Dye Degradation

Abstract

This study is focused on removal of dyes in water bodies using calcined egg shell powder obtained from waste egg shells as a new material for photocatalytic dye removal. The photocatalytic activity of calcined egg shell powder (CESP) was compared with the raw egg shell powder (RESP) under light and dark conditions. The results reveal that CESP has significantly a higher dye degradation capability of 80% compared to the RESP which is 20% under the same condition. Furthermore, under light conditions, CESP has shown nearly 50% increase in dye degradation compared to the same material in the dark. The kinetics of dye degradation follows pseudo-second-order kinetics suggesting the chemisorption process and the Freundlich adsorption isotherm is best fitted (R2 value is 0.96 for the linear fit) with the dye adsorption process. The application of CESP in industry is studied with a textile acid dye Lanasyn Rez F5B, and the results reveal it follows pseudo-second-order kinetics in dye removal.