Synthsis And Mechanism Study Of Rare Earth Compounds Via Solution Route

Due to their novel electronic, optical and magnetic properties, nano/micro- materials of lanthanide compounds have stimulated much scientific and technological interest.So it is much important to desigh and control the shape of nanocrystals. Chemical preparation of novel nanostructures and investigation of their formation process. may be a solution to the precise control of their structures,sizes and properties. In this dissertation, based on new synthetic strategies and the new chemical solution method, systematic explorations have been carried out. We have synthesize a series of nano/micro-materials of lanthanide via a hydrothermal method successfully and realized the control of nanomaterails of rare earth. The main contents of this thesis are summarized as following:(1) Monodisperse YVO₄ microspheres composed of building blocks have been synthesized on large scale through the two complexing agents cooperative assisted solution route. The shape and size of these as-prepared architectures can be tuned effectively by controlling the reaction conditions, such as reaction time, the molar ratio of complexing agent/Y³⁺, the structure of the complexing agent and rare earth precurors. As the typical architectures, the growth process of YVO4 spheres has been examined. To extend this method, other LnVO4 (Ln = Dy, Ho, Er) with the well-defined shape and dimensionality can also be achieved by adjusting different rare earth precursors. YVO4:Eu microspheres also have been synthesized through the method and its photoluminescence spectra have also been studied. This work sheds some light on the design of well-defined complex nanostructures, and explores the potential applications of the as-synthesized architectures.(2) The addition of transition mentals on CeO₂ greatly improved the catalytic activities. In this work, Ag-doped CeO₂ nanooctahedron was synthesized by the hydrothermal method using cerium nitrate hexahydrate and silver nitrate were precursor. This products have been synthesized on large scale through the PVP complexing agents assisted solution route. The shape and size of these as-prepared architectures can be tuned effectively by controlling the reaction conditions, such as reaction time, the amount of AgNO3. In addition, Nearly monodisperse Cu₂O/CeO₂ composite material with hollow microspheres shape have been synthesized by solvothermal routes. As a typical morphology, the growth process of monodisperse nanomaterials has been studied.(3) NaEuF₄ nanotubes have been synthesized on large scale through interface reaction without any complexing agents. The shape and size of these as-prepared architectures can be tuned effectively by controlling the reaction conditions, such as reaction time, the molar ratio of oil/water and Eu³⁺/F-. As the typical architectures, the growth process of NaEuF4 nanotubes has been examined.