H2分子在碱金属掺杂碳纳米管上的吸附特性

采用密度泛函理论研究了H₂在碱金属(M=Li, K)掺杂的扶手椅型单壁碳纳米管上的吸附. 对于碱金属管内掺杂, 模拟了4种氢吸附构型; 对于管外掺杂, 考虑了两种吸附结构, 同时还考虑了两种不同的掺杂浓度. 所有吸附模型都进行了全优化. 计算结果表明, 碱金属掺杂后, 碱金属与碳纳米管之间发生电子授受作用使得碱金属带正电荷, 对于金属Li, 管内掺杂更有利于电子向碳纳米管转移; 与管内掺杂相比, Li原子的管外掺杂更有利于H2分子吸附. 碱金属管外掺杂的碳纳米管吸附H₂的最稳定结构, 存在碱金属原子与H₂分子的配位作用.

Properties of H_2 Adsorption on the Alkali-metal-doped Carbon Nanotube

The H2 adsorption on the alkali-metal-doped armchair single-walled carbon nanotube was investigated using density functional theory(DFT) with full geometric optimization.The alkali metal doping both inside and outside the tube are considered.The calculations show that the electrons are transferred from the doped alkali-metal atoms to the carbon nanotube.Compared with the alkali-metal atom doping into the tube inside,the doping of alkali-metal atoms on the wall outside is more favorable to the H2 adsorption....