钴修饰单壁碳纳米管的贮氢性能
Hydrogen Adsorption of Co-decorated (5,5) Single-Walled Carbon Nanotube

本文利用密度泛函理论中的广义梯度近似系统地研究了Co原子修饰的(5,5)单壁碳纳米管(SWCNT)的贮氢性能。结果表明：Co原子以桥位的形式吸附于(5,5) SWCNT表面能量最低，在Co原子周围可以吸附3个完整的氢分子，Co原子的修饰提高了(5,5) SWCNT对氢分子的吸附能力。态密度图显示(5,5) SWCNT具有金属性，磁矩为0，Co-SWCNT和Co-SWCNT？nH2 (n=1？3)的磁矩为1 μB，氢分子的吸附未改变体系的磁性。Co-SWCNT？3H2的氢分子平均吸附能为0.51 eV，适中的吸附能有利于常温常压下实现可逆贮氢。
A comprehensive density functional theory (DFT) study of hydrogen molecules interaction with Co-decorated (5,5) single-walled carbon nanotube (SWCNT) was carried out. The most favorable position for Co adsorption on (5,5) SWCNT is the bridge site, and the Co atom can bind up to three H2 molecules. Hydrogen adsorption energy in Co-decorated SWCNT is improved compared to that of pristine nanotube. The DOS curve shows that the (5,5) SWCNT is metallic and the magnetic moment obtained is zero, indicating an antiferromagnetic behavior. The Co-SWCNT and Co-SWCNT？nH2 (n=1？3) systems have a magnetic moment of 1 μB. The average binding energy of the H2 molecules in Co-SWCNT？3H2 is 0.51 eV, which would allow storage and discharge to be cycled under ambient conditions.