Syntheses And Characterization Of Some Rare Earth Functional Nanostructured Materials

Nanostructured materials are a kind of materials in which at the least contain 1-100 nm size in one-dimension space. They have attracted a great deal of attention for their unique physical and chemical properties and more extensive potential applications in the various fields. At present, nanomaterials and nanotechnology have brought a great influence and revolution in science, technology and industry, so that the current time is called'the nano-age'. Among all the nano-materials, the rare earth nanostructural materials have been given more focus for the outstanding properties in electronics, magnetics and optics and catalysis, and wide application in materials, chemistry, physics and biology, medicine, military and agriculture.In this thesis we gave the definition, classification of nanostructural materials in the general sense. I reviewed synthesis, properties, potential application and progress of rare-earth phosphate, molybdate and tungstate. Bsaed on the general definition of nanostructural materials which divided into nanoparticle and nanoporous materials, I also introduced the rare earth nanoporous materials, especially rare earth coordination polymer. For the potential application of rare earth nanostructural materials in energy, environment and catalysis, we plan to prepare some unuform nanoparticles with various morphoogies or nanoporous materials.In the first part, We prepared some rodlike rare earth nanoparticls, such as CePO₄,LaPO₄,PrPO₄,NdPO₄,SmPO₄,EuPO₄,GdPO₄,DyPO₄ and platelike nanoparticles such as HoPO₄,ErPO₄,YbPO₄,YPO₄ via the hydrothermal treatment. Their structures, morphologies and stabilities were characterized by XRD,SEM,TEM and TG-DTA. The results showed the aspect ratio of those rodlike rare earth nanoparticles increases with the lower ratio of P/RE, while the particle size of the platelike one turns lager with the higher ratio. We found the morphologies of CePO₄ nanoparticles formed were influenced by the solution concentration, some chemical additives and solvents, for example, DMF resulted in some celluar namomaterials.In the second part, some sphere and platelike rare earth tungstate and molybdate nanoparticles were prepared in the different solvothermal condition such as DMF, 1,3-propanediol and propanol. We also found the size of platelike nanoparticles can increase with the mole ratio of WO₄/Ce.In the third part, We have synthesized twenty nanoporous coordination polymers, named RE-MOF-n (n=1²0) by the coordinating of aromatic carboxylic ligands such as NDC and BDC to some rare earth ions. Their structures and fluorescent properties and TG analyses were further observed.