Highly crystalline metal oxide nanoparticles such as CoO, ZnO, Fe(3)O(4), MnO, Mn(3)O(4), and BaTiO(3) were synthesized in just a few minutes by reacting metal alkoxides, acetates or acetylacetonates with benzyl alcohol under microwave heating.

Indium tin oxide nanoparticles with tin oxide contents varying from 2 to 30 wt % have been synthesized via a nonaqueous sol−gel procedure involving the solvothermal treatment of indium acetylacetonate and tin tert-butoxide in benzyl alcohol. According to powder X-ray diffraction analysis combined with Rietveld refinement all the materials are crystalline with the cubic bixbyite structure of indium oxide without any indication of SnO2 as an additional phase. Transmission electron microscopy studies proved that the nearly spherical particles are relatively uniform in size and shape with crystallite sizes in the range of 5−10 nm. X-ray photoelectron spectroscopy results showed that the final composition of the nanoparticles coincided well with the initial indium acetylacetonate-to-tin tert-butoxide ratio. Furthermore, a high amount of oxygen vacancies was detected, which contribute to the good electrical conductivity of the nanoparticles. Conductivity measurements on the as-synthesized nanopowders pressed into pellets showed a maximum conductivity of 2.56 S/cm at a dopant concentration of 15 wt % and can be further increased to 52.6 S/cm upon annealing under a nitrogen atmosphere.

The direct synthesis of crystalline titania nanorods by sol-gel chemistry in a special ionic liquid is reported. Unexpectedly, the high-temperature modification, rutile, is obtained directly under ambient conditions. X-ray diffraction and high-resolution transmission electron microscopy measurements support the highly crystalline and structural quality of the sample. The phase-directing property of the ionic liquids is attributable to the imide group in the counter ion, which exhibits strong interaction with specific rutile faces. Lithium insertion experiments were performed and revealed high and reversible loading capacities of up to 200 mAh g(-1).

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Antimony-doped SnO2 (ATO) nanopowders with high crystallinity were obtained by a polymer-assisted sol−gel process based on a novel amphiphilic block-copolymer (“KLE” type, poly(ethylene-co-butylene)-block-poly(ethylene oxide) and simple tin reagents (SnCl4 and Sb(OC2H5)3). As-synthesized samples were analyzed by Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron micrographs (TEM), N2 adsorption−desorption isotherms, and X-ray photoelectron spectroscopy (XPS). The results showed that the particles were the high crystalline ATO nanopowders of 5−8 nm primary particle size and the Sb was indeed incorporated into the SnO2 crystal structure (cassiterite SnO2). The as-prepared samples were used as negative electrode materials for lithium-ion batteries, whose charge−discharge properties, cyclic voltammetry, and cycle performance were examined. A high initial discharge capacity about 2400 mA h g−1 was observed at a constant discharge current density of approximately C/5 in a potential range of 0.005−3.0 V. A highly stable capacity of 637 mA h g−1 after 100 cycles is substantially higher than that of most previously reported SnO2 nanostructures. The high reversible capacity for ATO nanopowders may be due to the presence of Sb for Sn, leading to an improved formation of metals with respect to structure and formation dynamics from ATO.

The synthesis, structural characterization, and magnetic properties of crystalline manganese oxide nanoparticles are presented. The procedure is based on the reaction of benzyl alcohol with the two precursors: potassium permanganate KMnO 4 and manganese(II) acetylacetonate Mn(acac) 2 . Depending on the precursor used, the composition of the final product can be varied in such a way that in the case of KMnO 4 mainly Mn 3 O 4 is formed, whereas Mn(acac) 2 leads predominantly to MnO. Rietveld refinement of the XRD powder patterns, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and energy-dispersive X-ray (EDX) analysis, as well as electron energy loss spectroscopy (EELS) were employed for the structural characterization of the as-synthesized compounds. Especially the MnO manganosite nanocrystals exhibit some interesting features. HRTEM investigations point to the formation of a superstructure, which can be described as an ordered Mn vacancy cubic superstructure with the general formula of Mn 0.875 O x and a lattice parameter of 8.888 Å. The SQUID measurement proves a superparamagnetic behavior of the MnO nanoparticles.

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The synthesis as well as the electrochemical properties study of niobium-doped TiO2 (NTO) with mesoporosity and high surface area is presented. The mesoporous NTO was prepared using a novel poly(ethylene-co-butylene)-b-poly(ethylene oxide) amphiphilic diblock copolymer as a template and simple titanium reagents (TiCl4 and Nb(OC2H5)5) by a polymer-assisted sol−gel process. The samples were characterized by differential scanning calorimetry and thermogravimetric analysis (DSC-TGA), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (including high-resolution imaging-HRTEM), and the Brunauer−Emmett−Teller (BET). All samples are highly crystalline and have pore-solid architectures after removal of the polymer template by calcination. The resulting mesoporous NTO shows a high porosity of 46% and a high surface area of 128 m2/g, respectively. The as-prepared samples were used as positive electrode materials for lithium-ion battery, whose charge−discharge properties, cyclic voltammetry, and cycle performance were examined and revealed very good properties. A highly stable capacity of 160 mA h g−1 was found after 100 cycles.