Superior adsorption removal of dye and high catalytic activity for transesterification reaction displayed by crystalline CaO nanocubes extracted from mollusc shells

Abstract

Nano structuring and surface functionalization of industrially important Calcium Oxide (CaO) material has broad spectrum applications in daily civic life. In this context, cubical shape CaO nanoparticles are extracted via an eco-friendly green approach from dead mollusc shells collected from sea beaches. The surface structural morphology of as-prepared catalyst is thoroughly characterized by XRD, DLS particle size, SEM, TEM-EDS, TGA, TPD, BET surface area (80 m2g−1) analysis, adsorption and electro-kinetic (zeta potential/point of zero charge) properties etc. measurement. Practical applications of this cubic nano crystal (lattice constant 12.51 Å and size 60–80 nm) for adsorption removal of toxic neutral red dye and catalytic activity for transesterification are systematically studied relative to commercial CaO particles under similar experimental conditions. Influential factors responsible for optimum dye adsorption isotherms, kinetics/thermodynamics of catalytic activity, stability and reusability/leaching are properly investigated in correlation with its observed crystal structural and physicochemical properties.