γ-Al2O3 nanospheres-directed synthesis of monodispersed BaAl2O4:Eu2+ nanosphere phosphors

Abstract

Monodispersed BaAl 2 O 4 :Eu 2+ nanospheres with 180 nm size were synthesized through forced hydrolysis using c-Al 2 O 3 nanospheres as a template followed by a subsequent heat treatment. The incorporation of a barium precursor onto an individual c-Al 2 O 3 template nanosphere was optimized by controlling the reaction time. The photoluminescence properties of the BaAl 2 O 4 :Eu 2+ nanospheres were comparable to those of the bulk counterpart prepared at 1300 uC through a conventional solid-state reaction method. 22. The synthesized aluminum hydrous oxide nanoprecursors were calcined in air at 900 uC for 2 h to transform them into c-Al 2 O 3 .

Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications

“…This was ascribed to the 4f 6 5d → 4f 7 ( 8 S 7/2 ) transition of Eu 2+ , which was superimposed with the 4 F 9/2 → 6 H 15/2 transition of the Dy 3+ ions . Effects of size on the PL properties have been demonstrated with BaMgAl 10 O 17 :Eu 2+ , BaAl 2 O 4 :Eu 2+ , Nd 3+ , and SrAl 2 O 4 :Eu 2+ , Dy 3+ …”

Lanthanide-Activated Phosphors Based on 4f-5d Optical Transitions: Theoretical and Experimental Aspects

“…Along with morphological control, hard-template-directed synthesis also allows excellent control over the particle size and hierarchical structure in batch crystallization. For example, the Hong group reported the synthesis of monodispersed BaAl 2 O 4 :Eu 2+ nanophosphors using γ-Al 2 O 3 nanoparticles as the hard template . Another interesting demonstration can be found in the work of Xu and co-workers, who reported the formation of a core–shell structure through an incomplete removal of the hard template, as exemplified in the synthesis of SiO 2 @SrSi 2 O 2 N 2 :Eu 2+ oxynitride phosphors …”

UV, Blue, Green, Yellow, Red, and Small: Newest Developments on Eu2+-Doped Nanophosphors

“…Besides SrAl 2 O 4 :Eu 2+ , other aluminates, e.g., Sr 3 Al 2 O 6 :Eu 2+ , MgAl 2 O 4 :Eu 2+ ,Dy 3+ , CaAl x O y :Eu 2+ , BaMgAl 10 O 17 :Eu 2+ , BaAl 2 O 4 :Eu 2+ ,Nd 3+ , and CaAl 2 O 4 :Eu 2+ ,La 3+ , have been also reported. For instance, Sr 3 Al 2 O 6 :Eu 2+ spherical nanoparticles with diameters of 80–100 nm were prepared by means of a microwave-based method. − The resulting compound emits red light under 473 nm excitation, strongly distinguishing from the green emission of SrAl 2 O 4 :Eu 2+ .…”

“…Even though nanostructured luminescent materials present many advantages over the analogous bulk samples, the production of Eu 2+ -based nanophosphors is still in its early stages. The available literature on the field is mostly limited to aluminates, − borates, − halides, − ...…”