Synthesis of magnetic Fe3O4/hydroxyapatite nanocomposites and adsorption to Cu2+ ions

In the paper, magnetic Fe3O4/Hydroxyapatite (Fe3O4/HA) nanocomposites were prepared by a mechanical method and an in-situ method. XRD and SEM were used to characterize the microstructure and morphology. The adsorption performance of bare HA as well as the magnetic Fe3O4/HA nanocomposites to Cu2+ ions were investigated and compared. The results showed that the particle size of magnetic Fe3O4/HA nanocomposites synthesized in-situ had a uniform distribution. The crystallinity and the particle size were found to increase with the molar ratio of Fe3O4: HA and the hydrothermal reaction temperature. The magnetic Fe3O4/HA nanocomposites prepared by the two methods both have the ability to absorb Cu2+ ions. The removal efficiency of magnetic Fe3O4/HA nanocomposites in-situ to Cu2+ ions is 95%, higher than those by the mechanical method (91%). The adsorption capacity of Fe3O4/HA in-situ is higher than that mechanically and bare HA. The magnetic Fe3O4/HA nanocomposites can be completely separated by external magnetic field, so it has the potential of practical application in the heavy metal wastewater treatment.