Rh在单壁碳纳米管上吸附的密度泛函理论研究

Density functional theory study of rhodium adsorption on single-wall carbon nanotubes

本文利用密度泛函理论研究了Rh原子在(6,6)单壁碳纳米管内外的吸附行为.通过对Rh在单壁碳纳米管上不同吸附位的吸附构型与吸附能的研究发现:Rh吸附在管内、外的洞位最稳定,且管外吸附比在管内强.这是由于单壁碳纳米管的卷曲效应使得管外电荷密度比管内大造成的.态密度分析表明,吸附在管内外的Rh原子的5s电子均转移到了4d轨道上;Rh原子4d轨道上的电子转移到了(6,6)碳管上,使Rh带正电,碳管带负电.结合能带分析表明,Rh原子吸附在管内磁性较弱,而吸附在管外较强.

Rhodium adsorption on （6, 6） single-walled carbon nanotubes （SWCNTs） was systematically investigated by density functional theory. （ DFT）. According to the analysis of adsorption configurations and adsorption energies, it is found that the most stable configurations are I-H1, I-H2, O-H1, O-H2 and O-B1. The adsorption energy of O-H2 is - 2.29 eV, which is 0.49 eV higher than that of I-H2. This might be attributed to the graphite＇s winding effect, which the well-proportioned charge density on the graphite redistributes during the formation process of SWCNTs and then induces more charge to the outside of SWCNTs than the inside. Based on the partial density of states （PDOS） and Mulliken charge analysis, it is found that 5s electrons of Rh transfer to 4d orbit, while 4d electrons transfer to SWCNTs. Therefore, the Rh atom is positively charged, while the （6, 6） SWCNTs is negatively charged. Combining the PDOS calculations with the band structure results, the magnetism of Rh adsorbed outside of SWCNTs is higher than that inside SWCNTs.