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In recent years, along with chemistry, chemical engineering, energy, materials science and other areas of development, humans get a lot of new structural and functional materials. But it also brings a more serious environmental pollution problems. Therefore, people began to environmental protection and other related \People not only on the material for their own safety, and environmental protection with high performance requirements, with some non-toxic or low toxic materials to replace toxic materials, and materials for the preparation of the concept of green chemistry proposed that in the preparation process to achieve green. In this way, the material from the source to solve the pollution caused by the synthesis process, from the long-term point of view but also avoid the waste disposal problem that may arise. Green chemistry is the sustainable development of society is an important part of human survival and development has a very important significance. Green chemistry in the most representative, and that is the rise in recent decades supercritical fluid technology. Supercritical fluid technology is an emerging green technology, the most current research and application of supercritical water and supercritical CO2 technology. Among them, the supercritical water by virtue of its special physical and chemical properties and much people of all ages. In the energy, environment, materials of these three areas, supercritical water has proven to be a fast, efficient, environmentally friendly, energy-efficient reaction medium. Especially in the preparation of synthetic materials, the supercritical water system can be used to quickly and efficiently preparing high crystallinity, single phase, morphology unified monodisperse powder material. This article is mainly about supercritical water system in a multi-micro-nano-oxide YVO4.Y3A15O12 with BaTeMo2O9 applied research on materials synthesis. (1) successfully used high-temperature autoclave synthesis in supercritical water with a single phase, high crystallinity, high dispersion of rare earth ions doped YVO4 and YVO4 nanopowders, a detailed study of mixed rare earth ions, KOH added , reaction temperature and reaction time on product structure, morphology and size of the impact, and the synthesized YVO4: Eu and YVO4: Tb phosphor performance testing done. (2) the precipitation method Precursor reaction with supercritical water are combined, to explore a new type of autoclave use two-step reaction synthesis. Using this method in supercritical water systems successfully synthesized having a single phase, high crystallinity, high dispersion of nano-and micron powders Y3A15O12 and explore the experimental methods in detail, the precursor, the reaction temperature, reaction time, product was added in an amount of precipitant phase structure, morphology size. (3) the use of high temperature and pressure in supercritical water reactor systems were successfully prepared single-phase, uniform appearance of the new four yuan oxide BaTeMo2O9 micron plate material, systematically explored the reactants added sequentially, KOH added amount , reaction temperature, reaction time, cooling time, the reaction product was added in an amount of phase structure, morphology size effects and the obtained first sheet-like material of micron BaTeMo2O9 a detailed characterization and testing. BaTeMo2O9 micron plate material was successfully prepared for the next four yuan oxide micro-nano-materials synthesis has accumulated valuable experience, broadening the supercritical water this green technology in the field of materials synthesis range of applications, but also for the realization of four element oxide micro and nano technology provides a green, fast and efficient synthetic preparation. This article explores a new kind of chemical reaction media ---- supercritical water applications in the field of materials synthesis. From a unique perspective to carry out the preparation of new functional materials research, development of a technology roadmap harmony with the environment, the materials science and technology research and environmental issues and sustainable development of energy-saving chemical engineering combined. Findings in the field of basic science and applied technology have important significance.
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