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本工作使用GGA-PBE方法研究了H和O在含有V_1~V_4空位(5,5)单壁碳纳米管[1+1](H/[1+1])和[2+1](O/[2+1])加成反应的结合能、几何和电子结构.基于方向曲率理论提出的缺陷曲率包括原子曲率(KM-def)和键曲率(K_(D-def))预测了空位缺陷区不同原子和键的加成反应活性.计算结果表明,不管是[1+1]还是[2+1]加成,V_1和V_3空位缺陷中含有悬空键的C原子化学活性最强,且在[2+1]加成反应中C与O原子形成了羰基;对空位缺陷区其它原子或键,H与(5,5)管V_1~V_4空位缺陷区的原子结合能随K_(M-def)的增大而增大;O加成在大K_(D-def)的C—C键时,C—C键易被打断,形成C—O—C产物结构,且相应的结合能较大;O加成在小K_(D-def)的C—C键时,C—C键未被打断,形成三元环产物结构.H/[1+1]和O/[2+1]加成反应结合能除了主要受曲率的影响,还受到参与反应的C原子在(5,5)管最高占据分子轨道的电荷密度以及分波态密度的影响.这些研究将为含有空位缺陷碳纳米管的表面修饰提供理论依据.
In this work, we have investigated the effect of H and O on the growth and distribution of H_2 and O_2 in V_1 ~ V_4 vacancy (5,5) single-walled carbon nanotubes [1 + 1] (H / [1 + 1] / [2 + 1]) addition reaction.The geometries and electronic structures of the addition reaction are based on the curvature of curvature (KM-def) and the curvature of the bond (K-D-def) The results show that the C atom with dangling bonds in V_1 and V_3 vacancy defects has the strongest chemical activity at either [1 + 1] or [2 + 1] In the [2 + 1] addition reaction, the C and O atoms form a carbonyl group. The atomic binding energies of other atoms or bonds between H and (5,5) V_1 ~ V_4 vacancies in the vacancy- ) Increases; O addition in large K_ (D-def) of the C-C bond, C-C bond is easily interrupted, the formation of C-O-C product structure, and the corresponding binding energy than The C-C bond is not interrupted when O is added to the C-C bond of small K_ (D-def), resulting in a three-membered ring product structure.H / [1 + 1] and O / [2 + 1 ] The addition reaction The binding energy is mainly affected by the curvature and is also influenced by the charge density and the decoupling density of the C atoms participating in the highest occupied molecular orbit in the (5,5) tube. These studies will contain surface-modified carbon nanotubes vacancy defects provide a theoretical basis.