Approval of new DFG proposal for synthesis of nanosized functional materials in ionic liquids
The synthesis of nanoscaled materials doped with divalent lanthanide ions (Ln2+) consists of a massive challenge for advances in the field of luminescent materials. It happens, because most of the synthesis methods applied for preparing nanoscaled compounds are carried out in aqueous solution, easily oxidizing the europium ions from the divalent to the more stable trivalent oxidation state. Currently, the reduction of Eu3+ to Eu2+ is carried out in nanoparticles post-synthetically, by means of sintering treatments under reducing atmosphere. Hence, the usually applied high temperature of the sintering treatment e.g. 1000 °C cause the agglomeration of the nanoparticles. Differently than water and other commonly used solvents, ionic liquids (ILs) do not present an oxidizing character and allow the stabilization of the europium ions in the divalent oxidation state for the direct precipitation of Eu2+ nanoparticles without a sintering treatment. In addition, ILs can be applied as starting materials for fluoride nanoparticles instead of highly harmful chemicals as HF. Since beginning of 2014, this project is financially supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) as a part of the Priority Program „Material Synthesis near Room Temperature” (SPP 1708). Within the Inorganic Chemistry Group of the University of Siegen, this project is coordinated by Eugenie Geringer .