Self-assembled flowerlike europium-doped lanthanide molybdate microarchitectures and their photoluminescence properties

Three-dimensional flowerlike europium-doped lanthanide molybdate [La ₂(MoO₄)₃:Eu] microarchitectures that exhibit efficient photoluminescence have been successfully synthesized via a facile hydrothermal process in the presence of the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT). The La₂(MoO₄)₃:Eu microspheres are well dispersed, have a uniform diameter of about 3 μm, and are composed of nanoflakes of about 30-nm thickness that connect to each other by both edge-to-edge and edge-to-flat-surface conjunctions with few surface-to-surface attachments. The surfactant NaAOT was found to play a crucial role in achieving the good dispersibility and uniform morphology of the final product, as compared to the same material but synthesized without the surfactant. The UV absorption results illustrate that there is a 20-nm blue shift of CT band relative to bulk materials, which can be attributed to the quantum size effects of the nanoflakes. These La₂(MoO ₄)₃: Eu microspheres show efficient photoluminescence that is associated with the well-crystallized structures of the microarchitectures.