Borohydrides as Reducing Agents in the Synthesis of Inorganic Materials

该方案解决了在水溶液中使用硼氢化物作为还原剂，在室温下获得还原过渡金属氧化物和陶瓷-金属和金属-金属纳米复合材料的问题。通过对实验条件的控制，如pH、反应物的浓度和性质，以及好氧和厌氧环境，可以合成几种新型的钨、钼和钒的还原性氧化物。硼氢化物还原剂也将用于在室温下合成具有有趣磁性的陶瓷-金属和金属-金属纳米复合材料。产品将通过x射线衍射、热分析、化学分析、光谱技术、电子显微镜、电输运和磁测量来表征。观察到的性质将与晶体化学、化学成分和微观结构相关。对形成的产物进行彻底的表征将有助于理解硼氢化物还原反应过程中涉及的化学过程。这种认识可能为利用硼氢化物合成新的无机材料提供重要的见解。总的来说，拟议的研究由于其技术应用，如磁记录，而引起了人们的兴趣。提出的探索性研究可能会导致新相的动力学可及性，否则在较高温度下可能不稳定。无机固体通常是在高温下通过组分之间的反应来合成，以克服扩散的限制。这种苛刻的反应条件不仅会导致产物粒度较大，不均匀性，而且会导致亚稳相难以接近，价态异常。本研究提出了在水溶液中使用硼氢化物作为还原剂，在室温下获得几种新型还原过渡金属氧化物和陶瓷-金属和金属-金属纳米复合材料。总的来说，拟议的研究由于其技术应用，如磁记录，而引起了人们的兴趣。提出的探索性研究可能会导致新相的动力学可及性，否则在较高温度下可能不稳定。

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.