Liu Lu, Zhang Nannan, Leng Zhihua, Liang Yimai, Li Ruiqing, Zou Lianchun, Gan Shucai
College of Chemistry, Jilin University, Changchun 130026, P. R. China.
Dalton Trans. 2015 Apr 14;44(14):6645-54. doi: 10.1039/c5dt00581g.
This paper describes a simple and environmentally-friendly approach that allowed for the facile synthesis of a gadolinium-based core/shell/shell nanotube structure with a set of lanthanide ions incorporated into separated layers. In addition, by the rational design of a core/shell structure we systematically investigated the luminescence properties of different lanthanide ions in NaGdF4 host, and efficient down-conversion emission can be realized through gadolinium sublattice-mediated energy migration. The Gd(3+) ions play an intermediate role in this process. By changing the doped lanthanide ions, we generated multicolour emissions from the luminescent Ln(3+) centers via energy transfer of Ce(3+)→Gd(3+)→Ln(3+) and Ce(3+)→Ln(3+) (Ln = Eu, Tb, Dy and Sm) in separated layers. Due to the strong absorption of ultraviolet (UV) irradiation by Ce(3+) ions, the luminescence efficiency could be enhanced after doping Ce(3+) ions in the shell. In NaGdF4:5% Eu(3+)@NaGdF4@NaGdF4:5% Ce(3+) core/shell/shell nanotubes, with increasing the NaGdF4 interlayer thickness, a gradual decrease in emission intensity was observed for the Eu(3+) activator.
本文描述了一种简单且环保的方法，该方法能够轻松合成一种基于钆的核/壳/壳纳米管结构，其中一组镧系离子被掺入到不同的层中。此外，通过合理设计核/壳结构，我们系统地研究了NaGdF4基质中不同镧系离子的发光特性，并且可以通过钆亚晶格介导的能量迁移实现高效的下转换发射。Gd(3+)离子在这个过程中起到中间作用。通过改变掺杂的镧系离子，我们通过在不同层中Ce(3+)→Gd(3+)→Ln(3+)和Ce(3+)→Ln(3+)（Ln = Eu、Tb、Dy和Sm）的能量转移，从发光的Ln(3+)中心产生了多色发射。由于Ce(3+)离子对紫外（UV）辐射的强烈吸收，在壳层中掺杂Ce(3+)离子后发光效率得以提高。在NaGdF4:5% Eu(3+)@NaGdF4@NaGdF4:5% Ce(3+)核/壳/壳纳米管中，随着NaGdF4中间层厚度的增加，观察到Eu(3+)激活剂的发射强度逐渐降低。
