Synthesis And Properties Of The Tungstate Nanocrystals

Since 1990s, people have been deeply interested in research and development of the scintillation crystal. As an important inorganic material, metal tungstates have the wide range of applications in the photoluminescence, microwave, optical fiber, scintillator, humidity sensors, magnetic and catalyst. In this dissertation, the work is maily focused on tungstate nanomaterials, the goal is exploring novel synthetic methods and routes to synthesize tungstate micro- and nano-scal materials with controlled structures and morphologies. We got some high quality tunfstate nanomaterials by a facile composite-salt-mediated synthesis method. And, their optical, electronic and thermal properties have been studied. The main contents can be summarized as follows:Firstly, the raspite PbWO₄ nanobelts with length up to a few millimeters were obtained by a facile composite-salt-mediated synthesis method. Our investigation demonstrates that the raspite PbWO₄ nanobelts possess excellent blue-green luminescent property at low temperature and highly sensitive photocurrent response to light switches at room temperature.Secondly, the CdWO₄ nanowires were synthesized at room temperature and the CdWO₄ nanorods growed in the cadmium surface by a composite-salt-mediated synthesis method. acid nanowires of cadmium and by molten salt as reaction medium compound the of cadmium tungstate nanorods. Our investigation demonstrates that the CdWO₄ nano-materials possess excellent blue luminescent property at room temperature.Finally, the ZnWO₄ nanoparticles and ZnO nanoparticles coated with ZnWO₄ were obtained by a facile composite-salt-mediated synthesis method. Our investigation demonstrates that the ZnWO₄ nanoparticles possess excellent blue luminescent property at room temperature, and the ZnO nanoparticles coated with ZnWO₄ dye-sensitized solar cells can improve the open-circuit voltage.