Fluorescent Ultrashort Nanotubes from Defect-Induced Chemical Cutting
Fluorescent Ultrashort Nanotubes from Defect-Induced Chemical Cutting
复制标题
缺陷诱导化学切割产生的荧光超短纳米管
DOI：
10.1021/acs.chemmater.9b01196
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发表时间：
2019
影响因子：
8.6
通讯作者：
Wang, YuHuang
中科院分区：
文献类型：
--
作者：
Li, Yunfeng;Wu, Xiaojian;Kim, Mijin;Fortner, Jacob;Qu, Haoran;Wang, YuHuang
超短单壁碳纳米管（SWCNT）在短波红外线中发出明亮的荧光，可以在高分辨率生物成像和传感方面打开令人兴奋的机会。然而，由于合成的挑战，这种材料在很大程度上仍未开发。在这里，我们描述了一个高产量的荧光超短纳米管的合成的基础上，从根本上新的理解缺陷诱导的化学蚀刻单壁碳纳米管。我们首先沿纳米管侧壁沿着注入荧光sp3量子缺陷，然后用过氧化氢氧化切割成超短片段的纳米管。这种简单的两步过程导致具有窄长度分布（38 ± 18 nm）的荧光超短纳米管的合成，产率高达57%。尽管它们的超短长度，切割的单壁碳纳米管在短波红外线中以sp3缺陷的波长特征发出明亮的荧光，这提供了光谱指纹，使我们能够揭示这种缺陷诱导的切割过程的新见解。量子化学计算表明，这种蚀刻反应选择性地发生在羟基自由基（·OH）攻击周围富电子碳原子的缺陷部位。这项工作揭示了缺陷化学的基本见解，并使荧光超短纳米管合成访问这在很大程度上未经探索，但丰富的一类合成分子纳米结构的基础和应用研究。
Ultrashort single-walled carbon nanotubes (SWCNTs) that fluoresce brightly in the shortwave infrared could open exciting opportunities in high-resolution bioimaging and sensing. However, this material remains largely unexplored due to the synthetic challenge. Here, we describe a high-yield synthesis of fluorescent ultrashort nanotubes based on a fundamentally new understanding of defect-induced chemical etching of SWCNTs. We first implant fluorescent sp3quantum defects along the nanotube sidewalls and then oxidatively cut the nanotubes into ultrashort pieces using hydrogen peroxide. This simple two-step process leads to the synthesis of fluorescent ultrashort nanotubes with a narrow length distribution (38 ± 18 nm) and a yield as high as 57%. Despite their ultrashort length, the cut SWCNTs fluoresce brightly in the shortwave infrared at wavelengths characteristic of the sp3defects, which provides a spectral fingerprint allowing us to uncover new insights into this defect-induced cutting process. Quantum chemical computations suggest that this etching reaction occurs selectively at the defect sites where hydroxyl radicals (•OH) attack the surrounding electron-rich carbon atoms. This work reveals fundamental insights into defect chemistry and makes fluorescent ultrashort nanotubes synthetically accessible for both basic and applied studies of this largely unexplored but rich class of synthetic molecular nanostructures.