Synthesis, Characterization And Photoluminescence Properties Of Yttrium-basd Compounds Micro/Nano-structures

A serial of yttrium-based compounds including yttrium oxide, yttrium fluorideand yttrium coordination polymer with different morphologies and structures weresuccessfully fabricated via hydrothermal, solvothermal and ionthermal methods. Thestructure and morphologies of the products were characterized by a variety of testingtechniques, and the luminescence properties were also investigated. The maincontents of this thesis are as following:（1） Ionic-liquid assisted preparation and photoluminescence properties ofsquare-shaped Y2O3nanosheetsUniform square-shaped Y2O3nanosheets with length of about300nm andthickness of several nanometers have been successfully prepared by an ionic liquidassisted mixed solvothermal route followed by subsequent calcining treatment. Theproducts were analyzed by powder X-ray diffraction （XRD）, thermogravimetricanalysis （TG）, scanning electron microscopy （SEM） and transmission electronmicroscopy （TEM）. The effects of reaction durations, compositions of solvents, molarratios of reagents on the morphologies of the products have been investigated. Eu³⁺doped Y2O3nanosheets were also prepared and their photoluminescence propertieswere also investigated.（2） Preparation of YF₃from yttrium coordination polymerYF₃was prepared via a two-step method. Firstly, yttrium coordination polymerswere synthesized employing terephthalic acid as the building blocks. Then the yttriumcoordination polymers were reacted with NaF to produce YF₃. XRD, IR and SEMwere used to characterize the product. YF₃:Eu³⁺was also prepared and theirphotoluminescence properties were also studied.（3） Ionthermal synthesis of YF₃nanoparticlesNanoscaled YF₃particles with uniform morphologies have been facilelysynthesized by reacting yttrium nitrate with tetrabutylammonium fluoride （TBAF） viaan ionthermal process at120℃for12h. The phase confirmation and morphology ofthe as-prepared YF₃particles were investigated by X-ray powder diffraction （XRD）and scanning electron microscopy （SEM）. Results reveal that the YF₃nanoparticlesare about20nm in grain size. Eu³⁺doped YF₃submicroparticles were also preparedwith similar process and their photoluminescence properties were also evaluated.