Au掺杂CNT吸附NO的第一性原理研究

The first-principles study of NO adsorption on Au-doped CNT

碳纳米管(CNT)对于气体有超强的敏感性,可用于制备基于CNT的有害气体传感器.本文采用基于密度泛函理论的第一性原理研究Au掺杂CNT对NO和O_2的吸附特性.对吸附能、最终吸附距离、电荷转移量、态密度等的分析显示,Au掺杂使得CNT与NO间的交互作用明显增强,其中N原子端靠近CNT交互作用更强.禁带宽度和电荷密度分析表明,相比于NO分子中O原子端或者O2吸附,NO分子中N原子端与CNT发生交互作用会使体系导电性变化更为明显.说明Au掺杂能够很好地屏蔽空气中O_2对CNT导电性的影响,Au掺杂CNT作为NO气敏材料是可行的.

Carbon nanotubes(CNTs)are very sensitive to gases,and therefore can be used to fabricate CNT-based poisonous gas sensors.In this paper,the adsorption properties of NO and O 2 on Au-doped CNTs were investigated using the first principles on the basis of density functional theory.By analyzing the adsorption energy,final adsorption distance,charge transfer,and density of states,it was found that doping Au could enhance the interaction between CNTs and NO,and the adsorption at the N-atom end is much stronger.The analysis of forbidden band width and charge density shows that,compared with the adsorption at the O-atom end of NO or O 2,the electrical conductivity of Au-doped CNTs has a much more significant change after NO adsorption at the N-atom end,which indicates that doping Au could screen the effect of O 2 in air on the electrical conductivity of CNT.Therefore,taking Au-doped CNTs as NO sensing material is feasible.