碳的sp2和sp3峰/碳的Raman D峰和G峰

石墨碳基材料在拉曼光谱中的主要特征是G峰、D峰以及它的倍频峰2D峰。一阶G峰和D峰都是由于碳在sp2轨道的振动引起的,分别在1580 cm-1和1350 cm-1处,G峰对应于布里源区中心的E2g声子,D峰是由sp2原子的声张膜引起的缺陷峰,用于评估GNS中的缺陷水平和杂质含量这两处拉曼峰为类石墨碳(如石墨,碳黑,活性碳等)的典型拉曼峰。GNS的主要标志在2D峰处,这个峰的形状、位置、D波段的相对强度明显依赖于膜的层数,D、G峰的面积之比D/G随着芳香环数的增多而增多。
对于有时D和G峰并不是分离的很明显时,如果基线不在一个平面上,就要分峰,分峰拟合后,ID/IG是分峰拟合后两个峰的面积比,这个值越小,表示石墨化程度越高。目前基本都用强度比了,简单易用。其实把D峰分峰,可以用面积比比较缺陷还是杂质,甚至是哪种缺陷。就是太复杂了,所以基本没人用。

参见:
1. Sadezky A, Muckenhuber H, Grothe H, et al. Raman microspectroscopy of soot and related carbonaceous materials: Spectral analysis and structural information . Carbon, 2005, 43(8): 1731-1742.(http://dx.doi.org/10.1016/j.carbon.2005.02.018)
2. Sheng C. Char structure characterised by Raman spectroscopy and its correlations with combustion reactivity . Fuel, 2007, 86(15): 2316-2324. http://dx.doi.org/10.1016/j.fuel.2007.01.029

Raman spectroscopy was used to study the ordered/disordered crystal structures of carbonaceous materials. Thus, we utilized it to examine the changes that occurred in the structure of the graphene nanomeshes as compared to the as-prepared graphene oxide sheets, as shown in Figure 4. The well-known characteristics of carbon materials in Raman spectra are the G band ( 1580 cm-1 ), which is generally assigned to the E 2g phonon of sp 2 bonds of carbon atoms, and the D band ( 1350 cm-1 ) as a breathing mode of k-point phonons of A 1g symmetry, which is attributed to local defects and disorders, particularly the defects located at the edges of graphene and graphite platelets. The smaller I D /I G peak intensity ratio of a Raman spectrum can indicate lower defects and disorders of the graphitized structures containing the disorders caused at the edges of the carbon platelets.
ACS NANO VOL. 4 ▪ NO. 7 ▪ 4174–4180 ▪ 2010

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