Carbon nanotube (CNT) has received tremendous attention for potential use in many field due to its excellent physicochemical properties. However, the application performance derived from the electronic properties has remained a great challenge. Motivated by the electronic property of CNT, metal (M) such as silver (Ag), gold (Au) or platinum (Pt) doping effect on the electronic properties of CNT was investigated here. The hydroxyl-functionalized-CNT (OH-CNT) was taken as the model and the electronic of OH-CNT-M_n (M_n means metal clusters, n = 1~4) were studied based on first-principles. The formation of Ag-O bond makes the energy gap always present in OH-CNT-Ag_n and the energy gap of OH-CNT-Au_n cases with even atomic Au cluster disappears. However, only Pt-C bonds are formed and the energy gap is gradually reduced to no gap in OH-CNT-Pt_n. This theoretical study at the electronic level can give an idea for the research on the properties of metal-based CNT materials.

碳纳米管（CNT）由于其优异的理化特性而在许多领域中得到了潜在的广泛应用。然而，从电子特性获得的应用性能仍然是一个巨大的挑战。出于碳纳米管电子性能的动机，本文研究了金属（M），如银（Ag），金（Au）或铂（Pt）掺杂对CNT电子性能的影响。以羟基官能化碳纳米管（OH-CNT）为模型，并基于第一性原理研究了OH-CNT-M _n（M _n表示金属簇，n = 1〜4）的电子。Ag-O键的形成使能隙始终存在于OH-CNT-Ag _n和OH-CNT-Au _n的能隙中甚至原子金簇的情况也消失了。然而，在OH-CNT-Pt _n中仅形成Pt-C键，并且能隙逐渐减小至没有间隙。在电子层面的理论研究可以为金属基碳纳米管材料的性能研究提供思路。