Calcium oxide a sustainable photocatalyst derived from eggshell for efficient photo-degradation of organic pollutants

Combined application of nanotechnology and waste reutilisation process resulting in effective and cheap nano-photocatalyst have better dye degradation. Calcium oxide nanoparticles (Ca0 NPs) were synthesized from waste Eggshells (ES) by calcination process and characterized utilizing the analytical techniques such as XRD, SEM, EDAX, XPS and BET analysis. The synthesized CaO NPs were examined for photocatalytic dye degradation of two model dyes such as Methylene blue (MB) and Toluidine blue (TB) in aqueous medium. From the outcomes, it is clear that CaO effectively degraded both the dyes within 15 min (MB in 15 min and TB in 10 min). The studies include optimisation of parameter which found to be 7 pH, 20 ppm dye concentration and 50 mg of catalyst loading were effective operation condition. The kinetics of dye degradation follows pseudo first order, catalyst recycled for 7 cycles and chemical oxygen demand (COD) removal efficiency also analysed for degraded samples. (C) 2020 Elsevier Ltd. All rights reserved.