Quantitative Analysis of Zigzag and Armchair Edges on Carbon Materials with and without Pentagons Using Infrared Spectroscopy.
Quantitative Analysis of Zigzag and Armchair Edges on Carbon Materials with and without Pentagons Using Infrared Spectroscopy.
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DOI：
10.1021/acs.analchem.8b00949
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发表时间：
2018-08
影响因子：
7.4
通讯作者：
Tatsuya Sasaki;Yasuhiro Yamada;S. Sato
中科院分区：
文献类型：
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作者：
Tatsuya Sasaki;Yasuhiro Yamada;S. Sato
众所周知，碳材料的边缘结构（例如锯齿形边缘和扶手椅边缘）会影响其化学和电子性能。尽管已知红外光谱 (IR) 能够识别此类边缘结构，但仅使用面外 sp2C-H 弯曲振动进行红外光谱定量分析，并且边缘百分比的估计仍然具有挑战性。在这项工作中，通过分析面外 sp2C-H 弯曲和面内 sp2C-H 拉伸振动，开发了一种新颖的二维方法来量化具有和不具有五边形的碳材料的边缘结构。每种类型边缘上 sp2C-H 的校准因子是从各种参考化合物的实验和模拟红外光谱中获得的。使用校准因子，定量估计了具有锯齿形边缘（如并四苯）、扶手椅边缘（如屈）和锯齿形边缘（如晕苯）的碳化芳香族化合物的边缘结构。由在893K下碳化的并四苯、在933K下碳化的苯和在873K下碳化的晕苯，分别制备了具有20%的锯齿形边缘、38%的扶手椅边缘和67%的其他边缘的碳材料。该方法可用于定量分析最低933 K以下制备的各种碳材料的边缘结构。
Edge structures of carbon materials such as zigzag and armchair edges are known to affect their chemical and electronic properties. Although infrared spectroscopy (IR) has been known to be capable of identifying such edge structures, quantitative analysis using IR spectra has been conducted using only out-of-plane sp2C-H bending vibration, and the estimation of the percentage of edges is still challenging. In this work, a novel two-dimensional method to quantify edge structures of carbon materials with and without pentagons was developed by analyzing both out-of-plane sp2C-H bending and in-plane sp2C-H stretching vibration. Calibration factors of sp2C-H on each type of edge were obtained from experimental and simulated IR spectra of various reference compounds. Using the calibration factors, the edge structures of carbonized aromatic compounds with zigzag edges such as tetracene, armchair edges such as chrysene, and zigzag-like edges such as coronene were estimated quantitatively. From tetracene carbonized at 893 K, chrysene carbonized at 933 K, and coronene carbonized at 873 K, carbon materials with 20% of zigzag edges, 38% of armchair edges, and 67% of others edges were prepared, respectively. This method can be utilized as a quantitative analysis to determine edge structures of various carbon materials prepared below 933 K at the lowest.