Mesoporous Silica Encapsulating Upconversion Luminescence Rare-Earth Fluoride Nanorods for Secondary Excitation

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• 作者：Jianping Yang ; Yonghui Deng ; Qingling Wu ; Jing Zhou ; Haifeng Bao ; Qiang Li ; Fan Zhang ; Fuyou Li ; Bo Tu ; Dongyuan Zhao
• 刊名：Langmuir
• 出版年：2010
• 出版时间：June 1, 2010
• 年：2010
• 卷：26
• 期：11
• 页码：8850-8856
• 全文大小：948K
• 年卷期：v.26,no.11(June 1, 2010)
• ISSN：1520-5827

文摘

Mesoporous silica encapsulating upconversion luminescence NaYF₄ nanorods with uniform core−shell structures have been successfully synthesized by the surfactant-assistant sol−gel process. The thickness of ordered mesoporous silica shells can be adjusted from 50 to 95 nm by varying the amount of hydrolyzed silicate oligomer precursors from tetraethyl orthosilicate (TEOS), which further influences the BET surface area, pore volume, and the luminescence intensity. After coated with mesoporous silica shells, the hydrophobic nanorods is rendered to hydropholic simultaneously. The obtained β-NaYF₄@SiO₂@mSiO₂ core−shell nanorods possess high surface area (71.2−196 m² g⁻¹), pore volume (0.07−0.17 cm³ g⁻¹), uniform pore size distribution (2.3 nm), and accessible channels. Furthermore, the uniform core−shell nanorods show strong upconversion luminescence property similar to the hexagonal upconversion cores. The open mesopores can not only provide convenient transmission channels but also offer the huge location for accommodation of large molecules, such as fluorescent dyes and quantum dots. The secondary-excitation fluorescence of Rhodamine B is generated from the upconversion rare-earth fluoride nanorods cores to the fluorescent dyes loaded in the mesoporous silica shells.