Borohydrides as Reducing Agents in the Synthesis of Inorganic Materials

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Manthiram This proposal addresses the use of borohydrides as reducing agents in aqueous solutions to obtain reduced transition metal oxides and ceramic-metal and metal-metal nanocomposites at ambient temperatures. It is proposed to synthesize several novel reduced oxides of tungsten and molybdenum and vanadium by a careful control of experimental conditions such as pH, concentration and nature of the reactants, and aerobic vs anaerobic environment. The borohydride reducing agents will also be used to synthesize at ambient temperatures ceramic-metal and metal-metal nanocomposites that exhibit interesting magnetic characteristics. The products will be characterized by X-ray diffraction, thermal analysis, chemical analysis, spectroscopic techniques, electron microscopy, electrical transport, and magnetic measurements. The observed properties will be correlated with crystal chemistry, chemical composition and microstructure. A thorough characterization of the products formed will provide an understanding of the chemistry involved in the borohydride reduction-reaction process. Such an understanding might provide important insights in exploiting borohydrides for the synthesis of new inorganic materials. In general, the proposed studies are of interest because of their technological applications such as in magnetic recording. The proposed exploratory research may lead to a kinetic accessibility of new phases that may otherwise be unstable at higher temperatures. %%% Inorganic solids are generally synthesized by reaction between the components at high temperatures to overcome the diffusional limitations. Such harsh reaction conditions not only result in products with larger particle size and inhomogeneity, but also lead to an inaccessibility of metastable phases and unusual valence states. This proposal addresses the use of borohydrides as reducing agents in aqueous solutions to obtain several novel reduced transition metal oxides and ceramic-metal and metal-metal nano composites at ambient temperatures. In general, the proposed studies are of interest because of their technological applications such as in magnetic recording. The proposed exploratory research may lead to a kinetic accessibility of new phases that may otherwise be unstable at higher temperatures.