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Nanomaterials due mesoscopic effect exhibit different from conventional materials unique physical and chemical properties, and thus the synthesis and properties of nanomaterials has become the forefront of materials science, physics, and chemistry disciplines. Tungstates and molybdates are two important family of inorganic materials having a wide range of applications in the optical, microwave, a scintillator, a sensor, catalytic and other aspects. Synthesis of tungstate and molybdate, mainly citric acid method, solid-phase method, sol-gel method. However, these methods have certain limitations: the complexity of the synthesis process, requires a higher reaction temperature or long holding time, and the resulting particle size, morphology, irregular, etc.; Salt and hydrothermal method with synthetic low temperature, the process is simple, powder of uniform size, morphology can control advantages. For the first time successfully synthesized using molten salt method and hydrothermal method at low temperatures tungstates and molybdates nanomaterials on various factors discussed and identified nanomaterials synthesis required for optimal conditions and its growth mechanism and luminescence mechanism. Sodium tungstate (Na2WO4 · 2H2O) and zinc nitrate (Zn (NO3) 2.6 H2O) was prepared from precursor lithium nitrate as the reaction medium (melting point of 253 ° C), low-temperature molten salt synthesis got to have a good crystalline properties of rod ZnWO4 nanocrystalline powders. And X-ray diffraction (XRD), transmission electron microscopy (TEM) and room temperature fluorescence spectroscopy (PL) analysis techniques mine of sample preparation phase composition, crystalline morphology and luminescence properties were characterized. The results showed that: In the synthesis process, by adjusting the ratio of the reaction medium with the precursor and the holding time, without the need for any template, a surfactant, an organic solvent, and high-temperature process as auxiliary, it can be successfully obtained a synthetic coryneform ZnWO4 Nanocrystalline ; while the study also showed that the smaller particles have a better light emitting intensity. Sodium tungstate (Na2WO4 · 2H2O) and strontium chloride (SrCl2 · 6H2O) was prepared precursor to the the lithium nitrate reaction medium (melting point of 253 ° C), low temperature molten salt synthesis had good crystallinity performance, SrWO4 Nanocrystalline Powders; take advantage of XRD, SEM, TEM powder mineral composition and crystal morphology were characterized. Experimental results show that: The room temperature SrWO4 powders micron particles in molten salt system can obtain SrWO4 nanocrystalline. Molten salt conditions for the existence of the holding time and the ratio of the reaction medium and precursor have an important impact on SrWO4 nanocrystal crystallization properties and crystal morphology, and detailed discussion proposed dissolved recrystallization process. Cadmium nitrate (Cd (NO3) 2.4 H2O) and sodium molybdate (Na2MoO4 · 2H2O) as raw material, respectively, using the conventional method and reverse microemulsion prepared precursor, then under hydrothermal conditions 90oC insulation 20h Preparation the CdMoO4 microcrystalline, and analytical testing by means of XRD, TEM, SEM, PL the obtained CdMoO4 powder were characterized. Experimental results show that: The precursor was prepared by a conventional method, and then hydrothermal conditions to give the product as a micron scale; precursor was prepared by reverse phase microemulsion method, the same can be obtained under hydrothermal conditions morphology uniform the good dispersibility CdMoO4 nano crystal. In addition, nano-particles having a higher luminous intensity and the half width of peak of the fluorescence peak is also relatively large, which is related to the small size effect of the nano-particles. Sodium molybdate (Na2MoO4 · 2H2O) and Cd (NO3) 2.4 H2O as raw material, the use of micro-emulsion prepared precursor; the lithium nitrate reaction medium (melting point of 253 ° C), low temperature molten salts were prepared have different morphology, good crystallinity CdMoO4 microcrystalline particles. Analysis testing by means of the the obtained CdMoO4 samples were characterized with XRD, TEM, SEM, PL. Experimental results show that: the reaction medium under certain conditions and the proportion of precursor, to extend the holding time has a greater impact on CdMoO4 crystal morphology; the holding time under the same conditions, an increase in the proportion of the salt, morphology no crystallized right CdMoO4 to a greater impact.
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