单颗粒催化:测量单个纳米颗粒的化学反应活性,揭示个体差异性

        随着纳米科学的不断发展,纳米材料作为一种高效的催化剂,在能源转换与储存、环境保护、生命科学等领域发挥着越来越重要的作用。由于纳米材料本身固有的异质性导致催化剂粒子之间在尺寸、结构等方面存在差异,而纳米催化剂结构和组成上的微小差异可能造成催化性能上的很大不同。传统的平均统计测量可以反应系统整体的性质,但是掩盖了不同纳米粒子催化活性在空间和时间尺度上的异相性,这就促使我们从单粒子的水平出发挖掘纳米粒子在催化活性表现的‘共性’与‘个性’,以得到“结构”与“活性”的对应关系;最终目的是从本质上理解催化这一重要的化学行为,并能够将这些从实验室获得理论用于指导实际工业生产中催化剂的理性设计。

 


图1 利用SPRM技术研究半导体粒子间歇的光催化行为         图2 利用荧光染料标记催化产物-纳米气泡研究单粒子的光催化行为

                   (PNAS., 2017, 114, 10566.)                           (Chem. Sci., 2018, 9, 1448

 

代表性论文:

[1] Wei Wang, Imaging the chemical activity of single nanoparticles with optical microscopy, Chem. Soc. Rev., 2018, 47, 2485-2508.

[2] Fang Y, Li Z, Jiang Y, et al. Intermittent photocatalytic activity of single CdS nanoparticles. Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, 10566.

[3] Su H, Fang Y, Chen F, et al. Monitoring the dynamic photocatalytic activity of single CdS nanoparticles by lighting up H2 nanobubbles with fluorescent dyes. Chemical Science, 2018, 9. 1448.

 

Single Nanoparticle Catalysis
 

      Catalytic activity is probably one of the most attractive properties of nanomaterials. Numerous studies have demonstrated the varied catalytic activity between and within individual nanoparticles, thus driving the development of single nanoparticle catalysis in the past decades. Nanomaterials exhibit intrinsic heterogeneity among individuals, thus requiring a capability to study single nanoparticles. While electron microscopes often provide static images regarding its chemical composition, morphology and structure, imaging the chemical activity of single nanoparticles is highly desired to explore the structure-activity relationship via the bottom-up strategy, to understand the microscopic reaction mechanisms and kinetics, and to identify the sub-population with extraordinary activity. Recently, various optical microscopes have been emerging as powerful techniques towards this goal owing to their non-invasive nature, excellent sensitivity, diversified spectroscopic principles and sufficient spatial and temporal resolutions.

 

References:

[1] Wei Wang, Imaging the chemical activity of single nanoparticles with optical microscopy, Chem. Soc. Rev., 2018, 47, 2485-2508.

[2] Fang Y, Li Z, Jiang Y, et al. Intermittent photocatalytic activity of single CdS nanoparticles. Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, 10566.

[3] Su H, Fang Y, Chen F, et al. Monitoring the dynamic photocatalytic activity of single CdS nanoparticles by lighting up H2 nanobubbles with fluorescent dyes. Chemical Science, 2018, 9. 1448.

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