Ultrasound-Assisted Synthesis of Mesoporous Zirconia-Hydroxyapatite Nanocomposites and Their Dual Surface Affinity for Cr 3+ /Cr 2 O 7 2– Ions
Résumé
Zirconia-hydroxyapatite nanocomposites were prepared by solgel deposition of zirconium oxide from a zirconium alkoxide in the presence of apatite colloidal suspension under ultrasonication. The material porosity evolves from mainly
microporous zirconia to mesoporous hydroxyapatite, with decreasing surface area and increasing pore volume. XRD studies indicate that the apatite phase is well-preserved within the composite materials. The homogeneous dispersion of apatite colloids within the zirconia network was supported by TEM observations and nitrogen sorption measurements. 31P solid-state NMR studies suggest that partial dissolution of apatite may have occurred during the preparation, leading to the adsorption of phosphate species on zirconia particles. This is confirmed by XRD studies of nanocomposites after thermal treatment that demonstrate the preferred formation of tetragonal over monoclinic ZrO2 in the presence of hydroxyapatite. In order to investigate the surface properties of these novel materials, the adsorption of Pb2+, Cr3+, and Cr2O7 2‑ was evaluated. Metal cations were preferentially adsorbed on apatite-rich composites, whereas Cr2O7 2‑ shows a good affinity for the zirconia-rich phases. Zirconiaapatite materials showed the most promising performance in terms of recyclability. These nanocomposites that combine microporosity, mesoporosity and dual sorption properties for these species appear as interesting materials for metal ion remediation and may also find applications as biomaterials.
Domaines
MatériauxOrigine | Fichiers produits par l'(les) auteur(s) |
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