Ionic Liquid-Assisted Hydrothermal Synthesis of Rare Earth Luminescence Materials

Abstract

The shape control of nano-and microcrystals has received considerable attention because the morphology, dimensionality, and size of materials are well known to have great effects on their physical and chemical properties, as well as on their applications in optoelectronic devices. Ionic liquids were found to be very advantageous in synthetic nanochemistry, especially as templates and capping agents. Their particular phase behavior and unique physicochemical properties, including complex solvation interactions with organic and inorganic compounds, can provide various growth pathways for nanocrystals with novel morphologies and properties. This chapter gives an overview of existing ionic liquid-assisted hydrothermal method for the synthesis of rare earth luminescence materials. Particular attention is given to synthesis mechanism and the role of ionic liquids in the formation of specific morphology, as well as the effect of morphology on the luminescent properties.

The Melt of Sodium Nitrate as a Medium for the Synthesis of Fluorides

“…The use of ionic liquids for nanofluoride preparation represents a separate synthesis venue [78][79][80][81][82]. Ionic liquids are salts, containing large organic cations (usually, the unsymmetric ones), melt below 100 • C, and possess good thermal stability, high fire hazard safety, low corrosive activity, along with the low viscosity and vapor pressure.…”

“…Typical examples of ionic liquids include 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF 6 ), tetrafluoroborate (BmimBF 4 ), and/or chloride (BmimCl) [83]. These ionic liquids have been used successfully for the LnF 3 and NaLnF 4 rare earth nanofluoride syntheses [78][79][80][81][82] as solvents (ionic transport media) and as fluorinating agents (water traces initiate ionic liquid pyrohydriolysis). Synthesized nanopowders can be easily separated from ionic liquids by rinsing with methanol.…”