氟化物发光材料的离子液体辅助水热法制备与荧光性质研究

发布时间：2018-07-03 17:10

  本文选题：离子液体 + 水热法　； 参考：《浙江师范大学》2010年硕士论文

【摘要】： 上转换发光在全固态紧凑型激光器件(紫、蓝、绿区域)、上转换荧光粉、红外量子计数器、三维立体显示、温度探测器和生物分子的荧光探针等领域有较好的应用前景,一直是发光材料的一个研究热点。氟化物材料是一类重要的上转换发光基质材料,具有较低的声子能量、较高的发光效率等优点。在众多氟化物中,LaF3纳米晶体具有良好的热稳定性和环境稳定性、低的声子能量(低于350 cm-1)、容易掺杂稀土离子等优点。所以研究LaF3发光材料具有重要的意义。 传统制备纳米材料的方法中多用到各种有机溶剂或模板,这对反应条件的要求相当苛刻,所以找到一种简便、有效、绿色的合成方法已成为人们追求的目标。室温离子液体具有绿色环保,良好的热稳定性,较宽液程等优点,可以作为一种良好的反应介质满足无机材料合成的要求。水热法则是一种有效的合成无机材料的方法,具有以下优点：合成的颗粒纯度高、分散性好,晶形好且可控制、可通过对反应条件的选择控制产物的尺寸和形貌,且生产成本低。本文采用离子液体辅助水热法成功制备了氟化物发光材料,并研究了其结构和荧光性质。 本文的研究内容如下： 1、结合离子液体和水热法的优点,得到了一种简便、绿色的合成稀土氟化物发光材料的方法,即离子液体辅助水热法。在合成过程中,离子液体[bmim]BF4起到共溶剂和提供氟源的作用,在温度高于120℃时会水解产生F-离子,它与加入的稀土硝酸盐在180℃生成稀土氟化物发光材料。 2、通过XRD, FE-SEM对制备的LaF3:RE样品进行了结构表征,测试结果表明样品的颗粒大小为60 nm。LaF3:Er的样品在980 nm红外光激发下,发射出较强的绿光,通过功率关系得出其绿光和红光发射均为双光子过程,并讨论了其发光机制。LaF3:Eu(5%)和LaF3:Ce(15%),Tb(5%)样品在紫外光的激发下分别能观察到红光和绿光发射。和商业绿粉对比,通过测试计算出LaF3:Ce(15%),Tb(5%)样品的荧光量子效率是34%。结果表明LaF3:RE纳米颗粒在高分辨显示器、放大器和荧光粉等领域有潜在的应用。 3、通过离子液体辅助水热法制备了LaF3:Ce,Tb样品,并加入EDTA-2Na控制样品的形貌和大小。TEM数据和XRD估算表明,样品是直径为25 nm、厚度为5 nm的圆盘结构。在实验过程中EDTA-2Na在控制形貌和粒径大小方面起到了重要作用。系统研究了LaF3:Ce,Tb样品在254 nm紫外光激发下的荧光性质。结果表明LaF3:Ce,Tb颗粒可以应用于生物标记等领域。 4、通过离子液体辅助水热法制备了CaF2:RE纳米颗粒,TEM和SEM结果显示样品是球状结构,直径大约为150 nm。测试和研究了在254 nm激发下,CaF2:Ce,Tb样品的荧光性质；在397nm激发下,CaF2:Eu样品的荧光性质；在980 nm激发下,CaF2:Er样品的上转换发光性质。结果表明红光和绿光的发射均为双光子过程,紫光的发射为三光子过程。
[Abstract]:Up-conversion luminescence has good prospects in the fields of all-solid-state compact laser devices (purple, blue, green), up-conversion phosphors, infrared quantum counters, three-dimensional display, temperature detectors and fluorescent probes of biomolecules, etc. It has always been a research hotspot in luminescent materials. Fluoride is a kind of important upconversion luminescent matrix material, which has the advantages of low phonon energy and high luminous efficiency. Laf3 nanocrystals have many advantages, such as good thermal stability and environmental stability, low phonon energy (less than 350 cm-1) and easy doping of rare earth ions. Therefore, it is of great significance to study La F 3 luminescent materials. Various organic solvents or templates are often used in the traditional methods of preparing nanomaterials, which is very demanding to the reaction conditions. Therefore, finding a simple, effective and green synthesis method has become the goal of people's pursuit. Room temperature ionic liquids have the advantages of green environmental protection, good thermal stability, wide liquid range and so on. They can be used as a good reaction medium to meet the requirements of inorganic materials synthesis. The hydrothermal rule is an effective method for the synthesis of inorganic materials. It has the following advantages: high particle purity, good dispersion, good crystal shape and controllable shape. The size and morphology of the product can be controlled by selecting the reaction conditions. And the production cost is low. Fluoride luminescent materials were successfully prepared by ionic liquid assisted hydrothermal method and their structures and fluorescence properties were studied. The main contents of this paper are as follows: 1. Combining the advantages of ionic liquid and hydrothermal method, a simple and green method for the synthesis of rare earth fluoride luminescent materials, I. e., ionic liquid assisted hydrothermal method, has been obtained. In the process of synthesis, ionic liquid [bmim] BF4 acts as a co-solvent and provides a fluorine source. The rare earth fluoride luminescent material was formed at 180 鈩，

本文编号：2094351