Wang Yuran, Guo Yajie, Wang Guangjian, Wang Fei
School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui, China.
J Nanosci Nanotechnol. 2011 Apr;11(4):3162-70. doi: 10.1166/jnn.2011.3738.
A novel mesoporous TiO2 phosphor doped with Eu was synthesized through a facile hydrothermal synthesis method using cetyltrimethylammonium bromide as structure template reagent. The samples were characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscope, high-resolution transmission electron microscopy, ultraviolet visible diffuse reflectance, X-ray photoelectron spectroscopy, and three dimensional Photoluminescence. The X-ray diffraction results demonstrated that the products were anatase type with polycrystalline. N2 adsorption-desorption analysis showed that the samples were of high ordered double mesoporous structures. Eu-doped mesoporous TiO2 indicated the typical fluorescent spectra of Eu3+ ion occurred: the excited-states at 5L6 (394 nm), 5D2 (465 nm) and 5D1 (535 nm); the main emission peaks at 592 and 617 nm, corresponding with the transitions 5D0 --> 7F1 and 5D0 --> 7F2, respectively. Meanwhile, the phenomena of Eu(3+)-doped mesoporous TiO2 phosphor with efficient nonradiative energy transfer from the mesoporous TiO2 host to the activator Eu3+ ions was observed and possible emission mechanism was proposed. High dispersion of Eu in mesoporous TiO2 matrix was responsible for enhanced luminescence.
以十六烷基三甲基溴化铵为结构模板剂，通过简便的水热合成法合成了一种新型的Eu掺杂介孔TiO₂荧光粉。采用X射线衍射、N₂吸附-脱附、扫描电子显微镜、高分辨率透射电子显微镜、紫外可见漫反射、X射线光电子能谱和三维光致发光对样品进行了表征。X射线衍射结果表明，产物为多晶锐钛矿型。N₂吸附-脱附分析表明，样品具有高度有序的双介孔结构。Eu掺杂介孔TiO₂呈现出Eu³⁺离子典型的荧光光谱：5L₆（394nm）、5D₂（465nm）和5D₁（535nm）处的激发态；592和617nm处的主要发射峰，分别对应于5D₀→7F₁和5D₀→7F₂跃迁。同时，观察到Eu(3+)掺杂介孔TiO₂荧光粉中存在从介孔TiO₂主体到激活剂Eu³⁺离子的有效无辐射能量转移现象，并提出了可能的发射机制。Eu在介孔TiO₂基体中的高分散性导致了发光增强。
