利用理論計算來研究如何合成及修改奈米碳管

Abstract

奈米碳管的應用非常的廣泛，經過各種類型的研究，碳管在催化上能夠有良好的效果，其重點是研究各種缺陷位對於碳管之貢獻，而這裡則鎖定於graphite-like型式的氮參雜缺陷為主體，先比較四個氮的缺陷與三個氮的缺陷位的性質，也考量參雜不一樣的金屬原子，比較其形成能的變化趨勢，在觀察吸附不同小分子的吸附能，發現其3N與4N兩種不同的缺陷，形成完全不同的配位場。 接著利用包含空位缺陷，stone-wales缺陷，氧氣吸附的吸附位，與含氮之缺陷位，這幾種類型是可能在合成碳管中出現的結構，找出其不同類型的缺陷位所擁有的關聯性，來加以判斷在合成碳管的過程中，其可能的趨勢為何種情況，最後，為了能夠控制出其缺陷位之形狀，而也找出一種能夠修復空位太大之情況。

There are many applications of carbon nanotube (CNT). In recent researches, CNT has good efficiency to be a catalyst, and we thought it is an important role of different defect sites in CNT. The graphite-like nitrogen doped defect is compared with three and four nitrogen atoms- doped CNT(N-CNT), we also discuss dopants of different transition metals on CNT. Tendency of formation energy and the adsorption of small molecules are studied. It is demonstrated that different ligand field exist in those defect sites. Next, we consider vacancy defect site, stone wales defect and oxygen adsorption active site, because those sites may be stable in synthetic procedure of N-CNT. Then, we found they had connection with own defect site to discuss what possible mechanism in synthesis CNT. At last, we discussed one possible situation that can repair too bigger vacancy site on CNT.