稀土金属La吸附掺杂BN纳米管储氢性能的第一性原理研究

First Principles Study on the Hydrogen Storage Properties of La Doped BN Nanotubes

摘要:

本文采用基于密度泛函理论的第一性原理方法研究了稀土金属La吸附掺杂对单壁BN纳米管储氢性能的影响.通过分析计算结果得到稀土金属La可以稳定吸附到BN纳米管上，每个La原子最多可以吸附六个氢气分子，系统的储氢量能达到4.50 wt%，平均结合能为0.223 eV.根据态密度图分析可知，由于La的5d、6s轨道与BN纳米管中B、N原子的2p轨道发生杂化，使得La原子与其周围的原子发生了电荷转移，带正电的La原子将会极化吸附在其周围的氢气分子，使得更多的氢气分子聚集在其周围.本文的研究对于实验上合成高性能的BN纳米管储氢材料具有一定的指导意义.

Abstract:

The hydrogen adsorption on La-doped single BN nanotubes were investigated by first-principles based on density functional theory. Our calculated results show that the binding energy of La metal is large enough and ensure the stability toward recyclability. The maximum of six hydrogen molecules be adsorbed on the La-doped BN nanotube which can store up to 4.50 wt%. The density of states show that hybridizations between La-5p,5d ,6s states and B-2p, C-2p orbitals appear near the Fermi level. It is clear that the positive charge of La cation can polarize the incoming H2 molecules. The research of this paper has a certain guiding significance for the synthesis of high performance BN nanotube hydrogen storage materials.