Borohydrides as Reducing Agents in the Synthesis of Inorganic Materials

硼氢化物作为无机材料合成中的还原剂

• 批准号: 9401999
• 负责人: Arumugam Manthiram
• 金额: $ 21万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-15 至 1998-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9401999&HistoricalAwards=false
• 关键词: Borohydrides; Reducing; Agents; Synthesis; Inorganic

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.

该提案涉及在水溶液中使用硼氢化物作为还原剂，以在环境温度下获得还原的过渡金属氧化物以及陶瓷-金属和金属-金属纳米复合材料。建议通过仔细控制实验条件（例如pH值、反应物的浓度和性质以及有氧与无氧环境）来合成几种新型还原的钨、钼和钒氧化物。硼氢化物还原剂也将用于在环境温度下合成陶瓷-金属和金属-金属纳米复合材料，这些纳米复合材料表现出令人感兴趣的磁特性。这些产品将通过X射线衍射、热分析、化学分析、光谱技术、电子显微镜、电输运和磁性测量来表征。所观察到的性质将与晶体化学、化学组成和微观结构相关。对所形成的产物的彻底表征将提供对硼氢化物还原反应过程中所涉及的化学的理解。这种认识可能为开发硼氢化物合成新的无机材料提供重要的见解。一般来说，拟议的研究是感兴趣的，因为它们的技术应用，如在磁记录。拟议的探索性研究可能会导致新的阶段，否则可能是不稳定的，在较高的温度下的动力学可及性。 无机固体通常通过组分之间在高温下的反应来合成，以克服扩散限制。这种苛刻的反应条件不仅导致产物具有较大的颗粒尺寸和不均匀性，而且还导致亚稳相和不寻常的价态的不可达性。该提案提出了在水溶液中使用硼氢化物作为还原剂，以在环境温度下获得几种新型的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。 一般来说，拟议的研究是感兴趣的，因为它们的技术应用，如在磁记录。拟议的探索性研究可能会导致新的阶段，否则可能是不稳定的，在较高的温度下的动力学可及性。