Synthesis of Highly Porous Iron-Doped Carbonated Hydroxyapatite Spheres for Efficient Adsorption of Carmine Dyes

Abstract

Highly porous Fe-doped carbonate hydroxyapatite spheres (Fe-CHAs) were synthesized by two-step hydrothermal method and characterized by SEM, XRD and FTIR. Fe-CHAs with desirable hierarchical mesoporous structure exhibited BET surface area of 93.849 m2/g, pore diameter of 37.387 nm, and pore volume of 0.523 cm3/g. Carmine dye was chosen as model organic dye to investigate the adsorption properties of Fe-CHAs. The adsorption capacity of Fe-CHAs is about seven times as much as that of HA powder. Adsorption kinetics carmine dye molecules onto Fe-CHAs followed the second-order kinetic equation and Langmuir model, indicating that adsorption of carmine dye molecules onto Fe-CHAs is mainly monolayer chemical adsorption. Experimental results show that these highly porous Fe-CHAs could be a potential efficient adsorption material for removing organic dyes in industrial wastewater.