稀土氟化物纳/微米材料的水热合成、形成机理和发光性质

Hydrothermal Synthesis,Formation Mechanisms and Luminescence Properties of The Rare Earth Fluorides Nano-and Micro-materials

研究了稀土氟化物纳/微米材料的设计合成、形貌控制、形成机制以及发光性质。发展了一种简单、整体、没有模板、环境友好的水热方法合成系列稀土氟化物,即用有机添加剂柠檬酸钠(Na3C6H5O7.2H2O)作为配位剂和形貌控制剂,通过改变氟源(NaF,NH4F或NaBF4)和最初溶液的pH值,得到了具有不同成分、晶体结构、尺寸和形貌的稀土氟化物,包括REF3(RE=La～Lu,Y)以及六方相和立方相的NaREF4(RE=Y,Yb,Lu);最重要的是首次研究了具有各种晶体结构和形貌的镱、镥氟化物的可控合成。对各种产物可能的形成机理进行了合理、系统的讨论,并对各种基质中Eu3+,Tb3+掺杂的下转换和Yb3+/Er3+,Yb3+/Tm3+共掺杂的上转换发光性质进行了详细的研究。

The rare earth fluorides nano-and micro-materials as well as controlled morphologies,formation mechanisms and luminescence properties are studied in this paper.A facile,general,template-free and environmentally friendly hydrothermal methodology has been developed to prepare the whole rare earth fluorides nano-and microcrystals.Organic additive trisodium citrate plays double roles of coordination ligand and shape modifier in determining the morphologies of the final products.Through the precise tuning several critical parameters including F-sources（NaF,NH4F,NaBF4）,pH value in the initial solution and the choice of organic additives,the whole rare earth fluorides with various compositions,crystal structures,uniform sizes and morphologies have been obtained easily,including REF3（RE=La^Lu） as well as cubic and hexagonal phase NaREF4（RE=Y,Yb,Lu）.More importantly,for the first time,the controllable synthesis of ytterbium（or lutetium） fluoride compounds with diverse crystal phase and morphologies have been reported.The possible formation mechanisms for products with various architectures have been presented systematically.The photoluminescence properties of Eu3＋,Tb3＋-doped DC and Yb3＋/Er3＋,Yb3＋/Tm3＋-codoped UC NaREF4 or REF3 have also been investigated in detail.