title: Preparation of Magnesium, Cobalt and Nickel Ferrite Nanoparticles from Metal Oxides using Deep Eutectic Solvents.
abstract: Natural deep eutectic solvents (DESs) dissolve simple metal oxides and are used as a reaction medium to synthesize spinel-type ferrite nanoparticles MFe2 O4 (M=Mg, Zn, Co, Ni). The best results for phase-pure spinel ferrites are obtained with the DES consisting of choline chloride (ChCl) and maleic acid. By employing DESs, the reactions proceed at much lower temperatures than usual for the respective solid-phase reactions of the metal oxides and at the same temperatures as synthesis with comparable calcination processes using metal salts. The method therefore reduces the overall required energy for the nanoparticle synthesis. Thermogravimetric analysis shows that the thermolysis process of the eutectic melts in air occurs in one major step. The phase-pure spinel-type ferrite particles are thoroughly characterized by X-ray diffraction, diffuse-reflectance UV/Vis spectroscopy, and scanning electron microscopy. The properties of the obtained nanoparticles are shown to be comparable to those obtained by other methods, illustrating the potential of natural DESs for processing metal oxides.
authors: Institute of Organic Chemistry, University of Regensburg, Universitätsstrasse 31, 93047, Regensburg, Germany.
authors: Anika
authors: A
authors: Söldner
authors: Institute of Organic Chemistry, University of Regensburg, Universitätsstrasse 31, 93047, Regensburg, Germany.
authors: Julia
authors: J
authors: Zach
authors: Straubing Branch, Bio-, Electro- and Chemocatalysis (BioCat), Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Schulgasse 11a, 94315, Straubing, Germany.
authors: Melanie
authors: M
authors: Iwanow
authors: Straubing Branch, Bio-, Electro- and Chemocatalysis (BioCat), Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Schulgasse 11a, 94315, Straubing, Germany.
authors: Tobias
authors: T
authors: Gärtner
authors: Institute of Inorganic Chemistry, University of Regensburg, Universitätsstrasse 31, 93047, Regensburg, Germany.
authors: Marc
authors: M
authors: Schlosser
authors: Institute of Inorganic Chemistry, University of Regensburg, Universitätsstrasse 31, 93047, Regensburg, Germany.
authors: Arno
authors: A
authors: Pfitzner
authors: Institute of Organic Chemistry, University of Regensburg, Universitätsstrasse 31, 93047, Regensburg, Germany. burkhard.koenig@chemie.uni-regensburg.de.
authors: Burkhard
authors: http://orcid.org/0000-0002-6131-4850
authors: B
authors: König
keywords: deep eutectic solvents; ionic liquids; mixed metal oxides; nanoparticles