Multifunctional Lanthanide-Doped Binary Fluorides and Graphene Oxide Nanocomposites Via a Task-Specific Ionic Liquid.

Graphene oxide-based nanocomposites (NCMs) exhibit diverse photonic and biophotonic applications. Innovative nanoengineering using a task-specific ionic liquid (IL), namely, 1-butyl-3-methyl tetrafluoroborate [C 4 mim][BF 4 ], allows one to access a unique class of luminescent nanocomposites formed between lanthanide-doped binary fluorides and graphene oxide (GO). Here the IL is used as a solvent, templating agent, and as a reaction partner for the nanocomposite synthesis, that is, "all three in one". Our study shows that GO controls the size of the NCMs; however, it can tune the luminescence properties too. For example, the excitation spectrum of Ce 3+ is higher-energy shifted when GO is attached. In addition, magnetic properties of GdF 3 :Tb 3+ nanoparticles (NPs) and GdF 3 :Tb 3+ -GO NCMs are also studied at room temperature (300 K) and very low temperature (2 K). High magnetization results for the NPs (e.g., 6.676 emu g -1 at 300 K and 184.449 emu g -1 at 2 K in the applied magnetic field from +50 to -50 kOe) and NCMs promises their uses in many photonic and biphotonic applications including magnetic resonance imaging, etc.