曲率对Rh在锯齿型单壁碳纳米管内外吸附影响的研究  

Curvature effects on the Rh adsorption behavior inside and outside of the zigzag Single-Walled carbon nanotube

作　　者：刘莎[1] 吴锋民[1] 滕波涛[2] 

机构地区：[1]浙江师范大学凝聚态物理研究所,金华321004 [2]浙江师范大学化学与生命科学学院,金华321004

出　　处：《原子与分子物理学报》2011年第3期570-576,共7页Journal of Atomic and Molecular Physics

基　　金：浙江省自然科学基金青年科技人才专项(RC02069);国家重点基础研究项目(2006CB708612)

摘　　要：利用密度泛函理论系统的研究了单壁碳纳米管的曲率对Rh原子在锯齿型碳管内外吸附行为的影响,发现Rh原子在管外吸附比管内稳定;随着碳管管径的增加,曲率减小,管内外吸附能的差值逐渐减小,接近Rh原子在石墨烯上的吸附能.电荷密度分析表明,由于卷曲效应使碳纳米管管外的电荷密度大于管内,随着曲率减小,这种差别逐渐减小.管内外吸附Rh原子的Bader电荷差值及局域态密度差别亦随着曲率的下降而减小,这与Rh原子在管内外吸附能的变化规律相一致.The Rh adsorption behaviors inside and outside of a series of （n, 0） zigzag single-wailed carbon nanotubes （SWCNTs） were systematically investigated using density functional theory （DFT）. According to the optimized configurations and adsorption energies, it is found that the most stable configurations are I-H1 and O-H2. The adsorption energies of Rh outside the SWCNTs are higher than the inside ones. With the decrease of SWCNT curvatures, the differences of the adsorption energies between inside and outside configurations reduce, which are almost close to the adsorption energy on the graphene sheet. Charge density indicates that the well-proportioned charge density of the graphene redis- tributes due to the curvature effects, which leads more charge to the outside SWCNT than the inside one. The charge differences between the inside and outside decrease with the increase of the tube diameter, which is well consistent with the adsorption energy difference. Bader charge populations inside and outside of the SWCNTs also show the similar trend. According to the partial density of states （PDOS）, 5s electrons of Rh transfer to the 4d orbital, while 4d electrons transfer to the SWCNTs. Therefore, the Rh atom is positively charged, while the SWCNT is negatively charged.

关 键 词：单壁碳纳米管 电荷密度 密度泛函理论 曲率 态密度 

分 类 号：O[理学]