化学学报 ›› 2011, Vol. 69 ›› Issue (07): 777-782. 上一篇    下一篇

研究论文

硫脲修饰Cd掺杂ZnO水溶性量子点的制备及表征

赵斌,赵肃清*,张焜,刘端,苏娟   

  1. (广东工业大学轻工化工学院 广东 511400)
  • 投稿日期:2010-08-17 修回日期:2010-10-20 发布日期:2010-12-12
  • 通讯作者: 赵肃清 E-mail:suqingzhao@yahoo.com.cn
  • 基金资助:

    国家自然科学基金项目;广东省自然科学基金

Preparation and Characterization of Thiourea Modified Water-Soluble Cd Doped ZnO Quantum Dots

ZHAO Bin, ZHAO Su-Qing, ZHANG Kun, LIU Duan, SU Juan   

  1. (Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangdong 511400)
  • Received:2010-08-17 Revised:2010-10-20 Published:2010-12-12
  • Contact: Su-Qing ZHAO E-mail:suqingzhao@yahoo.com.cn

在非水稀溶液中以聚乙烯吡咯烷酮K-30为稳定剂, 硫脲为表面修饰剂, 制备Cd掺杂ZnO水溶性量子点荧光体|同时研究了基质的优化及硫脲含量对ZnO量子点发光性能的影响, Eu和Li的共掺杂对ZnO:Cd量子点发光性能的影响. 采用紫外光谱、荧光发射光谱、红外光谱和透射电镜、XRD对样品进行表征. 结果表明: 经Cd优化基质后、Eu和Li的共掺杂使量子点荧光强度明显增强|硫脲修饰后纳米颗粒分布更加均匀、晶粒更小、荧光光谱蓝移、量子点产率增加|该样品XRD衍射峰是馒头峰, 属于无定形态|红外光谱图中因硫脲引起的NH2和C—NH2伸缩振动吸收峰分别为3189.0, 1088.2 cm-1, 硫脲修饰的最佳浓度大约为32 mg/mL. 该量子点制备方法简单易行, 具有较好的稳定性及高荧光量子效率, 为进一步应用于生物标记奠定基础.

关键词: ZnO, Cd掺杂, 硫脲修饰, 荧光强度, 光谱蓝移

ZnO quantum-dots (QDs) capped with Cd were synthesized in dilute water-free solution with PVP K30 as a stabilizer and thiourea as a surface modification agent. The samples were characterized by UV absorption spectra, fluorescence emission spectra, Infrared spectra (IR), Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The effects of optimization of matrix and the thiourea concentration on the optical properties of ZnO QDs were studied. The effects of Eu, Li doping on the optical properties of ZnO:Cd was also studied. The results showed that the fluorescence intensity of quantum dots increased obviously after the matrix optimized by doping Cd and doping Eu, Li. It maked particle size distribution more uniform, the grain size more smaller, the main peak blueshift and the yield of quantum dots increase with the use of the thiourea. The XRD peaks of the sample were the broad scattering peaks, and belonged to amorphous form. NH2 and C—NH2 stretching vibration absorption peaks were 3189.0 and 1088.2 cm-1 in infrared spectra as a result of thiourea. The best concentration of thiourea was 32 mg/mL. This method was simple, quantum dots prepared by this method obtained good stability and strong fluorescence intensity. The approach introduced in this paper laid a solid foundation for the biological markers and applications of the quantum-dots.

Key words: ZnO, Cd doping, thiourea modification, the fluorescence intensity, blueshift