Study Of The Synthesis And Its Properties Of Several Rare-earth Nanomaterials

Rare-earth compounds have drawn much attention due to their unique physical and chemical properties in optics, electricity, magnetism, etc. In this dissertation, several rare-earth materials, such as rhombus-like SmCO3OH microplates, cross-like Pr2(C2O4)3·10H2O micro-particles and CeO2 nanorods, were synthesized via a simple liquid route without any surfactants. The products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). In addition, the thermal behavior, optic property and UV-visible absorption of the products were investigated. The main results obtained in this dissertation can be summarized as following:1. Rhombus-like SmCO3OH microplates were synthesized through a hydrothermal method using urea as the precipitance without any surfactant and template. The influence of the reaction conditions on the morphology of the product was investigated. The dosage of the urea is found to be the crucial factor that influences the morphology of the rhombus-like SmCO3OH microplates, 240℃, 8 h and 2 mmol dosage of (NH2)2CO are considered to be the preferable experiment parameters. The PL property of SmCO3OH:Eu3+ was investigated. The result shows that 1 at. % SmCO3OH:Eu3+ can produce a broad and strong emission band at 677 nm, which may be applied in producing light conversion film.2. Cross-like Pr2(C2O4)3·10H2O micro-particles were successfully synthesized through a precipitation method at room temperature without any surfactant. The dosage of the oxalate acid and the pH value of the solution were found to be the crucial factors that influence the morphology of the product. The optical property of the cross-like Pr2(C2O4)3·10H2O micro-particles at the room temperature was investigated by photoluminescence, and the result shows a potential application for solid-state laser. The thermal behavior of the product was investigated and Cross-like Pr6O11 micro-particles were obtained by calcinating the oxalate precursor. This approach can be applied in the synthesis of other lanthanide oxalates or lanthanide oxides.3. A large number of homogeneous CeO2 nanorods were synthesized by using Na2S·9H2O as the precipitant through a hydrothermal method. The effect of the reaction conditions on the product morphology was investigated. The UV-visible absorption property of the CeO2 nanorods was also investigated. The spectrum illustrates that there is a strong absorption band at 336 nm in the UV range. The comparative experiment shows that the strong base-weak acid salt Na2S·9H2O plays a significant role in the preparation of CeO2 nanorods. The pH value of the reaction system is maintained in a proper lever due to the hydrolysis of the Na2S·9H2O, which is propitious to CeO2 nanorod growth.