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近年来以煤为原料制备获得碳纳米管已经在实验室中得以实现,这开拓了碳纳米管低成本制备的途径。然而,煤基碳纳米管中氮、硅等原子掺杂对于碳管结构和功能性质影响的研究仍然相对较少。本研究使用基于第一性原理的自洽场晶体轨道法对硅、氮原子掺杂的(6,6)碳管进行研究。探讨硅、氮原子掺杂对碳纳米管电子性质和杨氏模量的影响。研究发现,氮原子和硅原子取代掺杂缺陷的形成在能量上是不利的,尤其对于硅掺杂。能带结构的计算表明,氮掺杂碳管显示金属导电性,而硅掺杂碳管发生了金属/半导体性质的转变,为半导体。杨氏模量的结果暗示,氮掺杂可以增强煤基碳管的力学性能。
In recent years, the preparation of carbon nanotubes using coal as raw materials has been achieved in the laboratory, which opens up ways for low-cost preparation of carbon nanotubes. However, the influence of atomic doping of nitrogen, silicon and other carbon-based carbon nanotubes on the structure and functional properties of carbon nanotubes is still relatively small. In this study, silicon and nitrogen-doped (6,6) carbon nanotubes were investigated using a self-consistent field-based orbital method based on first principles. The effects of silicon and nitrogen doping on the electronic properties and Young’s modulus of carbon nanotubes were investigated. It has been found that the formation of nitrogen and silicon atoms to substitute doping defects is energetically unfavorable, especially for silicon doping. The band structure calculations show that the N-doped carbon nanotubes show metal conductivity, while the silicon-doped carbon nanotubes undergo a metal / semiconductor transition as a semiconductor. The Young’s modulus results suggest that nitrogen doping can enhance the mechanical properties of coal-based carbon nanotubes.