SIOC English
化学学报
高级检索

化学学报 ›› 2010, Vol. 68 ›› Issue (19): 1971-1976. 上一篇    下一篇

研究论文

高分子模板对CdS量子点制备及其光催化性能的影响

丛日敏*,1,2，罗运军*,2，于怀清1   

  1. (1北京理工大学材料科学与工程学院 北京 100081)
    (2山东理工大学材料科学与工程学院 淄博 255049)
  • 投稿日期:2010-01-27 修回日期:2010-05-24 发布日期:2010-06-28
  • 通讯作者: 丛日敏 E-mail:congrimin0219@163.com
  • 基金资助:

    北京理工大学基础研究基金;山东理工大学科技博士基金资助项目

Effect of Polymer Templates on the Preparation and Photocatalytic Activity of CdS Quantum Dots

Cong Rimin*,1,2 Luo Yunjun*,2 Yu Huaiqing1   

  1. (1 College of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081)
    (2 College of Material Science and Engineering, Shandong University of Technology, Zibo 255049)
  • Received:2010-01-27 Revised:2010-05-24 Published:2010-06-28
  • Contact: CONG Ri-Min E-mail:congrimin0219@163.com

PDF

1578

被引次数

14

分别以球形聚酰胺-胺(PAMAM)树形分子和线形聚乙烯吡咯烷酮(PVP)两种结构不同的高分子为模板, 原位制备了分散良好的CdS量子点(CdS QDs), 并以甲基橙为降解对象, 研究了高分子模板结构对CdS量子点的制备和光催化性能的影响. 结果表明, 以PAMAM 树形分子为模板制备的CdS量子点(CdS QDs/PAMAM)比以PVP为模板制备的CdS量子点(CdS QDs/PVP)的尺寸分布更窄, 激子吸收峰更明显, 光致发光(PL)强度更高|并且在量子点尺寸接近的情况下, CdS QDs/PAMAM的催化效率明显高于CdS QDs/PVP. 这是由于PAMAM树形分子独特的结构有利于生成尺寸均匀的CdS量子点, 且不易钝化量子点表面的活性位点|而线性的PVP分子量分布较宽, 使制备的量子点的尺寸分布较宽, 且PVP分子链缠绕在CdS量子点表面, 钝化了部分活性位点, 降低催化效率. 此外, CdS QDs/PAMAM的催化能力随粒径减小而增大.

关键词: CdS量子点, PAMAM树形分子, 聚乙烯吡咯烷酮, 光催化, 甲基橙

Well dispersed CdS quantum dots (QDs) were in-situ prepared using poly(amidoamine) (PAMAM) dendrimers and poly(N-vinyl-2-pyrrolidone) (PVP) as templates respectively, and effects of both polymer templates on the preparation and photocatalytic properties of CdS QDs were studied through methyl orange degradation. The results show that the size distribution of PAMAM dendrimers-stabilized CdS QDs (CdS QDs/PAMAM) is much narrower than that of PVP stabilized CdS QDs (CdS QDs/PVP), and the exciton absorption peak and PL intensity of the former are much stronger. At the similar size, the photocatalytic efficiency of CdS QDs/PAMAM is much higher than that of CdS QDs/PVP. Differences in molecular structure between PAMAM and PVP are the major influence factors to the above contrast. PAMAM dendrimers are excellent templates for preparing CdS QDs with controlled size and narrow size-distribution. And most of the catalytic active sites in the surface of CdS QDs are not passivated by PAMAM dendrimer branches, which act as porous channels for methyl orange. However, many catalytic active sites in the surface of CdS QDs/PVP are passivated by the long twining PVP chains, which decrease the photocatalytic efficiency of CdS QDs/PVP. Besides, the narrower size-distribution of CdS QDs/PAMAM contributes to their high photocatalytic efficiency to some degree. In addition, the photocatalytic efficiency of CdS QDs increases when the size becomes smaller because of the larger specific surface area, stronger quantum confinement effect, and higher photo-production electron and hole energy of smaller QDs.

Key words: CdS quantum dots, PAMAM dendrimer, poly(N-vinyl-2-pyrrolidone), photocatalyst, methyl orange