非金属元素掺杂对VH_2解氢性能的影响

Influence of Nonmetal Dopants on the Dehydrogenation Properties of VH_2

采用基于第一性原理的密度泛函理论(DFT)结合平面波超软赝势方法,研究了非金属元素B,P,S掺杂对VH2解氢性能的影响。计算B,P,S掺杂VH2前后体系的合金形成热、净电荷、重叠集居数以及电子态密度,发现B,P,S掺杂VH2后:体系的合金形成热减少;部分V原子的净电荷增大、H原子的净电荷减小;费米能级处的电子浓度增大;态密度计算也显示了V-H之间的共振作用有所减弱。由此表明非金属元素B,P,S元素的掺杂减弱了系统的稳定性,提高了VH2的解氢性能。

In this paper, the influence of doping boron, phosphorus and sulfur on the dehydrogenation properties of VH2 is investiga- ted by using the plane wave ultersoft pseudopotential method which based on the first principle of density functional theory （DFT）. By calculating the negative alloy formation heat, net charge, overlap population and the electron density of state, we can find that the negative alloy formation of the B, P, S-doped alloy system decrease; the net charge of a part of V atoms increases and a part of H atoms decreases; calculated results of the electron density of state indicate that the electron density of Ef fermi level increases; the density of state calculations also showed that the resonance interaction between V and H decrease. So it comes to the conclusion that the system stability is weakened and the dehydrogenation properties of VHz can be improved by adding boron, phosphorus and sul- fur.