Design of magnetic and fluorescent Mg-Al layered double hydroxides by introducing Fe_3O_4 nanoparticles and Eu~(3+) ions for intercalation of glycine

摘要

We describe a novel route for the preparation of magnetic and fluorescent magnesium-aluminum layered double hydroxides by introducing Fe_3O_4 nanoparticles and Eu~(3+) ions. From the powder X-ray diffraction results, it was found that the Fe_3O_4 nanoparticles were highly dispersed in the inner void of octahedral lattice, and the Eu~(3+) ions substituted for the Al~(3+) ions and entered into hydrotalcite lattice through isomorphous replacement. Moderate introduction of Fe_3O_4 nanoparticles and Eu~(3+) ions did not change the lamellar structure of magnesium-aluminum layered double hydroxides. Glycine can also be intercalated into this magnetic and fluorescent layered double hydroxides by ion-exchange method. After intercalation of glycine, the basal spacing of magnetic and fluorescent layered double hydroxides increased from 7.6 to 8.8 A, indicating that glycine was successfully intercalated into the interlayer space of layered double hydroxides. Magnetic measurements reveal that these novel layered double hydroxides possess paramagnetic property at room temperature, and the emission and excitation spectra indicate the layered double hydroxides exhibit fluorescent property.