Luminescent nano-composites generated from a spray

The spray-pyrolysis (SP) synthesis technique has been employed to obtain SiO2:Eu3+ and γ-AlOOH:Eu3+. It was possible to obtain sub-micrometric spherical particles of SiO2 with luminescent Eu3+ ions bonded to the silica surface or embedded in amorphous silica beads, by controlling the synthesis and annealing process. Boehmite γ-AlOOH doped with Eu3+ nanoparticles were synthesized by SP at moderate temperature (200 °C) with Eu3+ ions bonded to the surface hydroxyls of the boehmite nanocrystals. Luminescent nano-composites were obtained by controlled reaction of γ-AlOOH:Eu3+ nanocrystals with ASN (asparagine). In these nano-composites, the Eu3+ are held at the surface of the boehmite nanocrystals and partially shielded from interactions with additional luminescence quenchers (hydroxyl groups, water molecules).