Precise determination of graphene functionalization by in situ Raman spectroscopy.
Precise determination of graphene functionalization by in situ Raman spectroscopy.
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DOI：
10.1038/ncomms15192
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发表时间：
2017-05-08
影响因子：
16.6
通讯作者：
Hirsch A
中科院分区：
文献类型：
--
作者：
Vecera P;Chacón-Torres JC;Pichler T;Reich S;Soni HR;Görling A;Edelthalhammer K;Peterlik H;Hauke F;Hirsch A
通过拉曼光谱可以很容易地验证石墨烯和相关碳同素异形体的成功共价功能化。然而，与加数共价结合相关的单个晶格模式的明确分配和分辨至今仍是难以捉摸的。在这里，我们提出了钾插层石墨的受控功能化的原位拉曼研究，揭示了在光谱的d区出现的几个新波段。随着功能化程度从低到中等水平的增加，这些波段的演变为量化功能化程度的不同组分的反褶积提供了基础。通过互补的DFT计算，我们能够识别出靠近加数的晶格碳原子的振动变化，并将它们分配到特定的拉曼模式。对插层石墨的功能化和再氧化过程的原位实验观察是提高对石墨烯化学性质理解的重要一步。拉曼光谱是一种多功能工具，可以深入了解石墨烯基材料的功能化，但迄今为止，与共价结合相关的振动模式的明确分配仍然难以捉摸。在此，作者成功地对该分子指纹进行了实验和理论鉴定。
The verification of a successful covalent functionalization of graphene and related carbon allotropes can easily be carried out by Raman spectroscopy. Nevertheless, the unequivocal assignment and resolution of individual lattice modes associated with the covalent binding of addends was elusive up to now. Here we present an in situ Raman study of a controlled functionalization of potassium intercalated graphite, revealing several new bands appearing in the D-region of the spectrum. The evolution of these bands with increasing degree of functionalization from low to moderate levels provides a basis for the deconvolution of the different components towards quantifying the extent of functionalization. By complementary DFT calculations we were able to identify the vibrational changes in the close proximity of the addend bearing lattice carbon atoms and to assign them to specific Raman modes. The experimental in situ observation of the developing functionalization along with the reoxidation of the intercalated graphite represents an important step towards an improved understanding of the chemistry of graphene. Raman spectroscopy is a versatile tool to gain insight into the functionalization of graphene-based materials, yet unequivocal assignment of the vibrational modes associated with covalent binding has so far remained elusive. Here, the authors succeed in an experimental and theoretical identification of this molecular fingerprint.