化学学报 ›› 2014, Vol. 72 ›› Issue (2): 257-262.DOI: 10.6023/A13050490 上一篇    

研究论文

Ag@SiO2@GdF3:Yb,Er核壳结构纳米材料的制备与增强上转换荧光

魏忠杰, 刘桂霞, 董相廷, 王进贤, 于文生   

  1. 长春理工大学化学与环境工程学院 应用化学与纳米技术吉林省高校重点实验室 长春 130022
  • 收稿日期:2013-11-08 出版日期:2014-02-14 发布日期:2013-11-26
  • 通讯作者: 刘桂霞,E-mail:liuguixia22@yahoo.com.cn;Tel.:0431-85582574;Fax:0431-85583085 E-mail:liuguixia22@yahoo.com.cn
  • 基金资助:

    项目受国家自然科学基金面上项目(No. 51072026)和吉林省科技发展计划项目(No. 20130206002GX)资助.

Preparation of Ag@SiO2@GdF3:Er,Yb Core-shell Structure Nanomaterials and Enhanced Up-conversion Luminescence

Wei Zhongjie, Liu Guixia, Dong Xiangting, Wang Jinxian, Yu Wensheng   

  1. School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun 130022
  • Received:2013-11-08 Online:2014-02-14 Published:2013-11-26
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 51072026) and the Development of Science and Technology Plan Projects of Jilin Province (No. 20130206002GX).

采用直接沉淀法成功制备了Ag@SiO2@GdF3:Er,Yb核壳结构纳米上转换发光粒子,并用XRD,TEM,UV-Vis,FTIR以及荧光光谱等对其结构和发光性能进行了表征. XRD分析表明:Ag表面包覆上了结晶良好的正交晶系的GdF3:Er,Yb. TEM照片显示:制备的复合纳米粒子具有明显的球形核壳结构,内核Ag粒子的直径约50 nm左右,包覆后的Ag@SiO2@GdF3:Er,Yb粒径约为80~120 nm,表面光滑且包覆完全. UV-Vis光谱证明:GdF3:Er,Yb和SiO2成功包覆在Ag核表面,包覆后Ag纳米粒子的表面等离子体共振吸收峰发生了红移. 荧光光谱表明:在980 nm激光激发下,该复合纳米粒子显示出和纯的GdF3:Er,Yb相同的Er3+的特征红色和绿色上转换发光,以位于655 nm处的Er3+离子的4F9/24I15/2的红光发射最强,并且复合粒子的发射光强度比纯的GdF3:Er,Yb有所增强.

关键词: GdF3:Yb,Er, 核壳结构, 上转换荧光

Noble metal nanoparticles such as Ag or Au and rare earth ions doped-up-conversion luminescence materials are all potential in the fields of biological labeling and sensing, diagnosis and biotherapy. When coupling with them together to form core-shell structure composites, noble metal nanostructures will present the strong surface plasmon resonances (SPRs), they can act as the function of "antenna", that is they can transfer the absorption energy to the luminescence particles and enhance their luminescence intensities. Moreover, when positioned in close proximity to metal surfaces, the luminescence materials can exhibit optical property changes (quenching or enhancement of luminescence), likely a result of the changed near-field electro-dynamical environment around the metal that arises from the collective oscillation of conduction electrons. This is a perfect model for studing the effects on luminescence properies of metal and luminescence materials. In this article, Ag nanoparticles were prepared by a glycol reduction method, and SiO2 spacers were coating on the surface of Ag nanoparticles by modified Stöber method, at last, the core-shell structure Ag@SiO2@GdF3:Er,Yb up-conversion luminescent nanoparticles were successfully synthesized by direct precipitation method. The structure and luminescence property of the samples were characterized by XRD, TEM, FTIR, UV-Vis and fluorescence spectra. XRD patterns show that the orthogonal phase GdF3:Er,Yb nanocrystals are coated on the surface of Ag cores. TEM images present that the obtained composites have obvious spherical core-shell structure, the diameter of the Ag core is 50 nm, the size of the Ag@SiO2@GdF3:Er,Yb composites is about 80~120 nm, the surface is smooth and the coating is complete, GdF3:Er,Yb nanoparticles are found obviously in the shell. UV-Vis spectra indicate that GdF3:Er,Yb and SiO2 are coated successfully on the surface of Ag, which increased the refractive index of local area around Ag nanoparticles, and the surface plasma absorption peaks of Ag have red shift. The up-conversion luminescent spectra also indicate that the core-shell structure composite particles have the same red and green up-conversion emissions as the pure GdF3:Er,Yb, their strong peaks are all near 655 nm corresponding to the 4F9/24I15/2 transition of Er3+. The fluorescent intensity of the core-shell structure composites is stronger than that of the pure GdF3:Er,Yb when the SiO2 as spacers, which indicates that Ag cores realize the up-conversion fluorescent enhancement of GdF3:Er,Yb. The luminescence intensity is enhanced with the increasing of silica thickness and the amount of GdF3:Er,Yb. This core-shell structure has a certain reference value for preparation of highly efficient rare earth up-conversion luminescent nanomaterials.

Key words: GdF3:Yb,Er, core-shell structure, up-conversion luminescence