The visible photoluminescence mechanism of oxidized multi-walled carbon nanotubes: an experimental and theoretical investigation
The visible photoluminescence mechanism of oxidized multi-walled carbon nanotubes: an experimental and theoretical investigation
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氧化多壁碳纳米管的可见光致发光机理：实验和理论研究
DOI：
10.1039/c2tc00043a
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Feng, Hui
中科院分区：
文献类型：
--
作者：
Qian, Zhaosheng;Zhou, Jin;Feng, Hui
通过柱色谱法分离了多壁碳纳米管氧化产物的主要成分，揭示了碳量子点高可见荧光的来源，并通过实验和理论方法支持了分离sp2碳团簇的氧化碳纳米管的弱近紫外-维斯荧光的性质。结果表明，在碳纳米管氧化过程中，生成了碳量子点、短氧化碳纳米管和长氧化碳纳米管三种主要组分。高可见光荧光主要来源于碳量子点，而短的和长的氧化碳纳米管仅显示出弱的近紫外-维斯荧光。针对氧化碳纳米管的荧光性质，通过对相应模型化合物的理论分析，比较和讨论了缺陷机制和孤立碳团簇机制两种解释。通过实验数据与计算值的比较，支持了荧光主要来源于被sp3碳氧化隔离的sp2碳团簇的观点。结果还表明，在氧化过程中，碳纳米管可以转化为大的氧化石墨烯。这项工作不仅清楚地证明了氧化碳纳米管混合物中高度可见荧光的起源和氧化碳纳米管荧光的合理解释，而且还为理解可见荧光氧化石墨烯和碳量子点提供了一个例子。
Dominant components of oxidized products of multi-walled carbon nanotubes were separated by column chromatography, the origin of highly visible fluorescence from carbon quantum dots was revealed, and the nature of weak near-UV-Vis fluorescence of oxidized carbon nanotubes from isolated sp2 carbon clusters was supported among the four proposed explanations through experimental and theoretical approaches. It was found that three dominant components including carbon quantum dots, short and long oxidized carbon nanotubes were produced during the oxidation of carbon nanotubes. The highly visible fluorescence was mainly originated from carbon quantum dots, while short and long oxidized carbon nanotubes only exhibited weak near-UV-Vis fluorescence. For the nature of fluorescence of oxidized carbon nanotubes, two proposed explanations including defects mechanism and an isolated carbon cluster mechanism were compared and discussed through theoretical analysis of corresponding model compounds. It was supported that the fluorescence is dominantly originated from sp2 carbon clusters isolated by sp3 carbons due to oxidation depending on the comparison between experimental data and calculated values. The results also indicated that carbon nanotubes can be transformed to large graphene oxide during oxidation. This work not only clearly demonstrated the origin of highly visible fluorescence in an oxidized carbon nanotube mixture and a reasonable explanation for fluorescence of oxidized carbon nanotubes, but also provided an example to understand visible fluorescent graphene oxide and carbon quantum dots.