Alkaline-earth Tungstate/molybdate And Rare Earth Fluoride Luminescent Materials: Synthesis And Luminescence Properties

The properties of nano-/micromaterials have a strong dependence on their size, shape, and dimensionality, and therefore the designing and controlling the morphology of nano-/micromaterials, understanding the complex growth process and exploring the basic principles are the focuses of chemistry and materials science. In this dissertation, the research is focused on the controllable synthesis, growth mechanism and luminescence properties of various rare earth nano/micromaterials.Uniform and well-dispersed BaMoO4:Ln3+(Ln=Eu, Tb, Dy, and Sm) spheres have been successfully synthesized through a hydrothermal process by using tri sodium citrate as surfactant. The structure, morphology, possible formation process, and luminescence properties of the as-obtained BaMoO4samples were investigated in detail. XRD results demonstrate that Ln3+-doped samples can be well indexed to the pure tetragonal scheelite-type BaMoO4, SEM and TEM images indicate that the as-obtained BaMoO4microspheres. Moreover, this synthesis route may be of great significance in the preparation of other well-defined molybdate functional materials.Uniform and well-dispersed SrWO4hierarchical microspheres have been synthesized using a facile hydrothermal process in the presence of trisodiun citrate and sodium dodecyl benzenesulfonate (SDS). XRD and SEM results demonstrate that the as-synthesized SrWO4particles are high purity well crystallized and exhibit a relatively uniform spherical morphology. More-over, the luminescent properties of lanthanide activator ions Ln3+(Ln=Tb, Eu, Dy, and Sm) doped SrWO4samples, which may find potential applications in optical displays and light-emitting diodes, were investigated in detail.We present a simple wet-chemical approach to fabricate YF3:Eu3+architectures with different sizes and morphologies at ambient pressure and low temperature without any catalysts, templates, or substrates. The structure, morphology, and luminescence properties of the as-obtained YF3:Eu3+products were investigated in detail. The as-obtained YF3:Eu3+samples exhibit orange-red emission corresponding to the5D0-7F1transition of the Eu3+ions under UV excitation. This synthesis approach, which needs neither high energy nor complicated processes or equipment, may be of significant importance in industrial applications as a consequence of low costs, benignancy to the environment, and synthetic convenience.