Density Functional Theory Method for Study of the Mechanism of C–H Bond Formation on Finite-Sized Graphene Surface
Density Functional Theory Method for Study of the Mechanism of C–H Bond Formation on Finite-Sized Graphene Surface
复制标题
密度泛函理论方法研究有限尺寸石墨烯表面C-H键形成机理
DOI：
10.1143/jjap.49.06gj12
复制
发表时间：
2010
影响因子：
1.5
通讯作者：
T. Iyama
中科院分区：
文献类型：
--
作者：
H. Tachikawa;T. Iyama
采用密度泛函理论（DFT）方法研究了有限尺寸氢化石墨烯的结构和电子态。作为氢化石墨烯体系的模型，检查了不同尺寸的五种石墨烯（n=2、4、7、14和19，其中n表示石墨烯中苯环的数目）。对应于C-H伸缩模的谐振频率与C-H键长呈线性关系。氢原子加成形成的C-H键在平衡结构中完全极化为Cδ--Hδ+。发现激活势垒是由过渡区中sp2到sp3的杂化形成的。在理论分析的基础上，对石墨烯表面C-H键的形成机理进行了讨论。
The structures and electronic states of hydrogenated graphenes with a finite size have been investigated by a density functional theory (DFT) method. Five graphenes of various sizes (n=2, 4, 7, 14, and 19, where n indicates the number of benzene rings in graphene) were examined as models of a hydrogenated graphene system. The harmonic vibrational frequency corresponding to a C–H stretching mode showed a linear relationship between the frequency and the C–H bond length. The C–H bond formed by the addition of hydrogen atoms was completely polarized as Cδ-–Hδ+ in an equilibrium structure. It was found that the activation barrier is formed by hybridization from sp2 to sp3 in the transition region. The mechanism of C–H bond formation on a graphene surface was discussed on the basis of theoretical results.