Efficient surface grafting of luminescent silicon quantum dots by photoinitiated hydrosilylation
Efficient surface grafting of luminescent silicon quantum dots by photoinitiated hydrosilylation
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DOI：
10.1021/la0509394
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发表时间：
2005-06-21
期刊：
影响因子：
3.9
通讯作者：
Ruckenstein, E
中科院分区：
文献类型：
--
作者：
Hua, FJ;Swihart, MT;Ruckenstein, E
我们提出了一种将有机分子高效（高覆盖率）接枝到光致发光硅纳米颗粒上的方法。高覆盖率接枝是通过使用一种改进的蚀刻工艺来实现的，该工艺在纳米颗粒表面上产生一个终止氢的表面，并且在接枝过程中小心地排除氧气。以前不可能在自由硅纳米颗粒上产生如此干净的h端表面，随后也不可能在没有大量表面氧的情况下产生接枝颗粒。这使我们能够(1)制备空气稳定的绿色发射硅纳米颗粒，(2)在各种有机溶剂中制备接枝硅纳米颗粒的稳定分散体，其中颗粒可以很容易地通过添加非溶剂沉淀，干燥和再分散，(3)使用常规色谱方法根据尺寸（因此发射颜色）分离这些纳米颗粒，(4)保护颗粒免受化学攻击和光致发光猝灭，(5)在颗粒表面提供进一步衍生化的官能团。我们还利用H-1核磁共振表明，光引发的硅氢化反应并没有特异性地将末端碳原子接枝到表面，而是在第一个和第二个原子上都发生了连接。
We suggest a method for efficient (high-coverage) grafting of organic molecules onto photoluminescent silicon nanoparticles. High coverage grafting was enabled by use of a modified etching process that produces a hydrogen-terminated surface on the nanoparticles with very little residual oxygen and by carefully excluding oxygen during the grafting process. It had not previously been possible to produce such a clean H-terminated surface on free silicon nanoparticles or, subsequently, to produce grafted particles without significant surface oxygen. This allowed us to (1) prepare air-stable green-emitting silicon nanoparticles, (2) prepare stable dispersions of grafted silicon nanoparticles in a variety of organic solvents from which particles can readily be precipitated by addition of nonsolvent, dried, and redispersed, (3) separate these nanoparticles by size (and therefore emission color) using conventional chromatographic methods, (4) protect the particles from chemical attack and photoluminescence quenching, and (5) provide functional groups on the particle surface for further derivatization. We also show, using H-1 NMR, that the photoinitiated hydrosilylation reaction does not specifically graft the terminal carbon atom to the surface but that attachment at both the first and second atom occurs.