碳纳米管负载矾的第一性原理研究

Study on the first-principles of vanadium supported by carbon nanotubes

本文基于密度泛函第一性原理研究了原始和带有缺陷的(Stone-Wales缺陷和单空位缺陷)碳纳米管负载金属V的稳定构型.对于V吸附在原始碳纳米管(CNT)上时,V在内表面的吸附比外表面的吸附有更强的相互作用力,且六元环内表面结构最稳定.当V与Stone-Wales缺陷碳纳米管相互作用时,V原子易吸附在管外七元环C-C键的外表面和内表面处,这说明缺陷位置的有效结合使之局域化加强.而以单空位缺陷碳纳米管为载体时V最易吸附在外缺陷处,相当于碳纳米管的一个C被金属V原子取代,形成了3个V-C_(sur)键,这进一步表明SV管外吸附比管内吸附更容易.我们从上述三种构型载体中发现,金属V吸附在缺陷碳纳米管时的稳定性要优于原始碳纳米管,且SV缺陷对金属V的固定效果最好.

The stable configuration of metal V supported on original and defective carbon nanotubes(Stone-Wales defects and single-vacancy defects) are studied by the first principles of density functional theory. For V adsorption on the original carbon nanotubes(CNT),the adsorption of V on the inner surface has a stronger interaction with the adsorbed on the outer surface,and the inner surface structure of the six-membered ring is the most stable. When V interacts with Stone-Wales defective carbon nanotubes,the V atoms are easily adsorbed outside and inner surface of the C-C bond in the seven-membered ring,indicating that the effective combination of the defective position is localized. When the single-vacancy defective carbon nanotubes are used as the carrier,V is most likely to be adsorbed to the external defects,which is equivalent to a C of the carbon nanotubes being replaced by a metal V atom,and three V-C_(sur) bonds are formed,which further indicates that external adsorption of single vacancy carbon nanotubes is easier than internal adsorption. From the above three configuration carriers,we found that the stability of metal V adsorbed on defective carbon nanotubes is better than that of the original carbon nanotubes,and single vacancy defects have the best fixation effect on metal V.