Morphology-controlled Synthesis Of Rare-earth-ions-doped Borate And Aluminate Luminescent Materials And Properties Study

Morphology-controlled synthesis, wettability, and photoluminescence properties of rare-earth-ion doped borate and aluminate luminescent materials were systematically studied in this dissertation. The formation mechanism of various morphologies was briefly discussed as well. The main contents could be summarized as follows:(1) Three-dimensional YBO3:Eu³⁺ with different morphologies such as nest-like, rose-like, cruller-like and flower-like were hydrothermally synthesized by simply adjusting the ratios of surfactant polyethylene glycol-6000 to octadecylamine. These three-dimensional architectures were all fabricated by nanoflakes through different assembly modes. PEG-6000, ODA, and the ODA/PEG ratio played important roles in the formation process of various architectures. The films fabricated by the samples obtained under the different ratios of PEG-6000 to ODA could exhibit tunable wettability ranged from superhydrophilicity to superhydrophobicity.(2) NaYF4:Eu³⁺nanorods have been successfully prepared by a designed chemical conversion method. The YBO3:Eu³⁺ microballs precursors were first prepared through a simple hydrothermal process. Subsequently, NaYF4:Eu³⁺nanorods were synthesized at the expense of the precursors by a hydrothermal conversion process. The as-obtained YBO3:Eu³⁺ microballs, NaYF4:Eu³⁺nanorods all have strong luminescence. (3) TbBO3:Eu³⁺ microspheres and microflakes were synthesized by a facile hydrothermal route in the absence of organic additives, catalysts, and templates. The as-obtained samples exhibit a high luminescent intensity.(4) We use a facile but efficient hydrothermal synthesis of nanosheets bundles precursors in the absence of organic additives, catalysts, and templates, and followed by thermally splitting the precursors approach for synthesizing single-crystal SrAl2O4:Eu2+,Dy³⁺ nanosheets for the first time. The experimental results show that urea is very efficient to form nanosheets bundles precursors. The as-obtained SrAl2O4:Eu2+,Dy³⁺ nanosheets exhibit higher photoluminescence intensity (emission peak at 516 nm) compared with commercial powders. Furthermore, the SrAl2O4:Eu2+,Dy³⁺ nanosheets can sustain visible light in dark places more than 16 h.