Submicrometer-Sized Hierarchical Hollow Spheres of Heavy Lanthanide Orthovanadates: Sacrificial Template Synthesis, Formation Mechanism, and Luminescent Properties

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• 作者：Xiaoyan Yang ; Lin Xu ; Zheng Zhai ; Fangfang Cheng ; Zhenzhen Yan ; Xiaomiao Feng ; Junjie Zhu ; Wenhua Hou
• 刊名：Langmuir
• 出版年：2013
• 出版时间：December 23, 2013
• 年：2013
• 卷：29
• 期：51
• 页码：15992-16001
• 全文大小：581K
• ISSN：1520-5827

文摘

Hollow spheres of heavy lanthanide orthovanadates (LnVO₄, Ln = Tb, Dy, Er, Tm, Yb, Lu) and yolk鈥搒hell structures of Ho(OH)CO₃@HoVO₄ have been successfully prepared by employing Ln(OH)CO₃ colloidal spheres as a sacrificial template and NH₄VO₃ as a vanadium source. In particular, the as-obtained LuVO₄ hollow spheres are assembled from numerous hollow-structured elliptic nanoparticles, and their textural parameters such as the inner and outer diameters, shell thicknesses, and number of shells could be finely tuned through introducing different amounts of NH₄VO₃ and employing Lu(OH)CO₃ templates with different sizes. The possible mechanisms for the formation of hollow spheres and yolk鈥搒hell structures, and also the hollow-structured elliptic nanoparticles of LuVO₄, i.e., building blocks of LuVO₄ hollow spheres, are proposed and discussed in detail. Under ultraviolet excitation, the obtained LuVO₄:Eu³⁺ hollow spheres show strong red emissions located in the saturated color region, and the modulation of emission intensity and color purity could be realized by tuning the textural parameters of the obtained hollow spheres. It was found that the nanostructure of the building blocks of LuVO₄:Eu³⁺ hollow spheres also had an effect on the luminescent properties of the as-obtained materials. Moreover, the quantum efficiency could be affected by the textural parameters of the as-obtained LuVO₄:Eu³⁺ hollow spheres, and the double-shelled LuVO₄:Eu³⁺ hollow sphere has the highest quantum efficiency. In addition, the excellent biocompatibility indicates the potential biological applications of LuVO₄ hollow spheres.