Europium(III) Fluoride Nanoparticles from Ionic Liquids: Structural, Morphological, and Luminescent Properties

Abstract

Inorganic luminescent materials (phosphors) find widespread scientific and industrial applications. For potential applications, nanoscale phosphors are favored because of the reduced scattering and the possibility to miniaturize devices. In such materials, the optical behavior is strongly dependent on impurities or defects in the crystal lattice, so that a well-defined reaction protocol with fixed parameters is compulsory to ensure the quality of the obtained material. The fast and facile conversion of europium acetate via microwave radiation with and in different tetrafluoroborate ionic liquids to oxygen-free, hexagonal EuF3 nanoparticles is investigated in detail. The study of the influence of the different reaction parameters on the structural, morphological, and luminescent properties predominantly reveals a strong influence of the chosen ionic liquid. The particle morphology varies from small spherical particles to rods forming different types of aggregates, such as bundles, columns, or spherical agglomerations. The luminescence spectra show the characteristic orange-red emission due to the dominating 5D0 → 7F1 transition of Eu3+. The 5D0 quantum efficiency could be tuned from 2% up to 44% depending on the ionic liquid used for synthesis.

Sonochemical Synthesis of 0D, 1D, and 2D Zinc Oxide Nanostructures in Ionic Liquids and Their Photocatalytic Activity

“…[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Recent developments in the use of room temperature ionic liquids (RTILs) as reaction media for inorganic nanomaterials have mainly focused on taking advantage of the preorganized structure of the RTILs to template porous inorganic nanomaterials and the intrinsic high charge and polarizability of the RTILs to create electrostatic and steric stabilization for nanoparticles. [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] Much attention has been devoted to the preparation of nanostructured inorganic materials with various morphologies by ultrasound synthesis and sonochemistry. [54] The physical phenomenon responsible for the sonochemical process relates to acoustic cavitation, which occurs in several stages, including the creation, growth, and implosive collapse of bubbles formed in the liquid.…”

Ionic Liquid‐based Synthesis—A Low‐Temperature Route to Nanophosphates

“…Interestingly, different product morphologies were observed for the different lanthanide ions under the same reaction conditions. [18] For YPO 4 hollow nanotubes with an inner diameter of about 50 nm and an outer diameter of 200-300 nm were obtained. This might be of particular interest for optical applications as a second phosphor material could be incorporated, leading to advanced luminescence materials.…”

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

“…In this case [BMIM]BF 4 slowly releases fluoride anions by hydrolysis [93]. It is important to mention that the use of ILs has been suggested as a green alternative to the conventional organic solvents for the synthesis of inorganic compounds [94,95] [96], and rhombic-like LuF 3 NPs, obtained after a solvothermal process at 150°C of ethanolic solutions containing the corresponding RE nitrates and 1-octyl-3-methylimidazolium hexafluorophosphate (OmimPF 6 ) [97].…”