中文摘要：

掺氮碳纳米管（N-CNTs）因其独特的理化性质,在诸多领域呈现广阔的应用前景.伴随N-CNTs的大量生产和使用,其将不可避免地释放到环境中.进入环境中的N-CNTs可以与污染物发生吸附作用,进而改变二者的环境行为和生态风险.目前,N-CNTs对水中有机污染物的吸附行为鲜有报道.本研究构建了不同掺杂浓度/形态的掺氮单壁碳纳米管（N-SWNTs）,基于密度泛函理论,模拟水中芳香类有机污染物在N-SWNTs上的吸附.计算结果表明,氮掺杂可以提高N-SWNTs对芳香类化合物的吸附性能.掺杂浓度和掺杂形态会影响N-SWNTs的吸附能力,高浓度吡啶氮掺杂的N-SWNTs对芳香类化合物具有较强的吸附作用.化合物与N-SWNTs之间主要发生物理吸附,疏水作用和π–π相互作用是化合物在N-SWNTs上吸附的主要作用力,污染物官能团可加强其与N-SWNTs之间的吸附作用.本研究可为N-SWNTs的生态风险评价提供一定的理论指导.

英文摘要：

N-doped carbon nanotubes（N-CNTs） are widely used in various fields due to their excellent characters. They will be inevitably released into the environment with their extensive use. The adsorption of organic compounds on N-CNTs may affect the environmental behavior and ecological risk of both N-CNTs and pollutants. However, only few studies have been performed on the adsorption of organic compounds on N-CNTs in water. In this study, we constructed 20 N-doped single-walled carbon nanotubes（N-SWNTs） with different doping configurations and doping concentrations and simulated the adsorption of aromatic pollutants on N-SWNTs by density functional theory（DFT） calculations. Our simulation results indicated that N doping can increase the adsorption affinity of aromatic compounds on SWNTs, and doping configurations and doping concentrations show significant effect. Pyrid-N doped SWNTs with vacancy defect have a good performance on adsorption. The adsorption of aromatic compounds on N-SWNTs in water is physisorption. Hydrophobic interaction and π–π stacking are the main interaction forces. Functional groups of benzene derivatives（-NO2,-OH,-NH2）, can enhance electrostatic interactions between the aromatics and N-SWNTs. Our study will provide a theoretical guide for future ecological risk assessment of N-SWNTs.