Au nanoparticles loaded Hydroxyapatite catalyst prepared from waste eggshell: synthesis, characterization and application in VOC removal

Abstract

Abstract Eggshell, which is made almost entirely of calcium carbonate, is among the most abundant waste materials from poultry production. In 2018, the worldwide egg production exceeded 78 million metric tons which contributed to over 8 million metric tons of eggshell waste. However, this waste can be converted into useful materials for several industrial applications. Herein, hydroxyapatite (HAp) of fine particles was prepared using a green synthesis procedure in water medium from eggshell waste. Then, HAp was utilized as support material for loading different contents of Au nanoparticles (0.2 and 0.5 wt%). The materials were characterized by Brunauer-Emmett-Teller (BET) surface area analysis, Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), X-ray diffraction (XRD). The prepared catalysts were used for VOCs oxidation of formaldehyde in continuous flow and humid condition. In this study, Au/HAp (0.2 wt%) exhibited superior catalytic activity with good low-temperature reproducibility and high dispersion of particles on the surface of hydroxyapatite. Hence, hydroxyapatite prepared from eggshell waste is considered as a promising support material for noble metal catalysts for VOCs oxidation.