Graduate School of Science & Engineering, Tokyo Institute of Technology, Tokyo, Japan.
J Colloid Interface Sci. 2011 Nov 15;363(2):456-64. doi: 10.1016/j.jcis.2011.07.066. Epub 2011 Aug 5.
Europium (III) (Eu(3+))-doped nanoporous silica spheres were synthesized, and the states of Eu(3+) ions in the silica framework structure were investigated. The ordered nanopores were preserved with the doping at the Eu(3+) molar concentration to Si up to 10 mol%, and the O-Si-O and Si-OH groups in the structures were clearly rearranged with the doping, indicating the interaction of Eu(3+) with the O atoms. The significant morphological changes in the spheres were observed with the doping. The photoluminescence spectral shapes due to the transitions of (5)D(0)-(7)F(1) and (5)D(0)-(7)F(2) were indicative of the presence of the Eu(3+) in an environment of a low symmetry. It was found that the Eu(3+) was located inside the silica framework to electrostatically interact with the environmental O atoms, which would prevent the aggregation among Eu(3+) ions to show the efficient luminescence. Therefore, the interactions between the Eu(3+) ions and silica framework structures in the spheres were successfully clarified.
掺铕（III）（Eu(3+)）的纳米多孔硅球被合成，并研究了 Eu(3+)离子在硅骨架结构中的状态。在 Eu(3+)摩尔浓度至 Si 10 摩尔%的掺杂下，有序纳米孔得以保留，结构中的 O-Si-O 和 Si-OH 基团明显重新排列，表明 Eu(3+)与 O 原子相互作用。掺杂后观察到球体的显著形态变化。由于（5）D(0)-(7)F(1)和（5）D(0)-(7)F(2)跃迁引起的光致发光光谱形状表明 Eu(3+)存在于低对称性环境中。发现 Eu(3+)位于硅骨架内部，通过静电相互作用与环境 O 原子相互作用，这将阻止 Eu(3+)离子之间的聚集，从而显示出高效的发光。因此，成功阐明了球体中 Eu(3+)离子与硅骨架结构之间的相互作用。
