Acta Chimica Sinica ›› 2020, Vol. 78 ›› Issue (2): 170-176.DOI: 10.6023/A19120445 Previous Articles    


SiO2介导的5 nm金颗粒的高效富集及其催化活性研究

李威a,d, 冉铁成c, 张瑜a,b, 何威a,d, 马继飞a, 汪启胜b, 张继超a,b, 诸颖a,b   

  1. a 中国科学院上海应用物理研究所 物理生物学研究室 上海同步辐射光源生物成像中心中国科学院界面物理与技术重点实验室 上海 201800;
    b 张江实验室 上海高等研究院 中国科学院 上海 201210;
    c 武汉中原瑞德生物制品有限责任公司研发部 武汉 430206;
    d 中国科学院大学 北京 100049
  • 投稿日期:2019-12-12 发布日期:2020-02-17
  • 通讯作者: 张继超
  • 基金资助:

SiO2-Mediated High-efficiency Enrichment of 5 nm Gold Nanoparticles and Their Catalytic Activity

Li Weia,d, Ran Tiechengc, Zhang Yua,b, He Weia,d, Ma Jifeia, Wang Qishengb, Zhang Jichaoa,b, Zhu Yinga,b   

  1. a Shanghai Institute of Applied Physics, Division of Physical Biology, Shanghai Synchrotron Radiation Facility Bioimaging Center, CAS Key Laboratory of Interfacial Physics and Technology, Shanghai 201800;
    b Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210;
    c Wuhan Zhongyuan Ruide Biological Products Corporation Limited R&D, Wuhan 430206;
    d University of Chinese Academy of Sciences, Beijing 100049
  • Received:2019-12-12 Published:2020-02-17
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 11705270, 11675251, 21390414), the Shanghai Sailing Program (No. 17YF1423600), the China Postdoctoral Science Foundation (Nos. 2018M632189, 2018M640340) and the Youth Innovation Promotion Association of CAS (Nos. 2012205, 2016236).

Gold nanoparticles (Au NPs), smaller than 10 nm, have a high ratio of surface area to volume, and therefore have excellent catalytic activity. They are widely used in the field of catalysis. The concentration of small particle sized Au NPs synthesized by traditional wet chemical method is too low, and further enrichment is needed in order to meet the experimental requirements. However, small particle sized Au NPs are prone to aggregate during the concentration process and lose the catalytic activity. It is a challenge to concentrate the small Au NPs while keeping their catalytic activities. In this work, 500 nm silanized SiO2 particles which are covered by positive charges were used to adsorb 5 nm Au NPs through electrostatic interaction, and self-assemble to form Au NPs@SiO2 composite at room temperature. The loaded efficiency of Au NPs can reach 99.5% and the amount of Au NPs particles loaded on each SiO2 particle reached 800~1000, which greatly increased the effective concentration of Au NPs in the local area. Moreover, Au NPs enriched on the surface of SiO2 were bound by electrostatic action and uniformly distributed on the surface of SiO2 without agglomeration. The results showed that the catalytic activity of AuNPs@SiO2 was greatly enhanced by increasing the local concentration of AuNPs, and the catalytic activity was 3 times higher than that of AuNPs at the same concentration. After 5 times of reuse, the catalytic conversion efficiency remained at about 80%. The Au NPs@SiO2 composite could be preserved for one month with the same structure and catalytic activity. Moreover, by adjusting the molar ratio of SiO2 and Au NPs, the assembly density of Au NPs at SiO2 can be precisely regulated, and the catalytic activity of Au NPs@SiO2 can also be changed precisely. This work provides a simple method for preparing small sized Au NPs with high concentration and greatly improves the catalytic activity of Au NPs. The method has wide application in enriching other small sized nanoparticles.

Key words: gold nanoparticles, catalytic activity, enrichment, the electrostatic interaction