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采用密度泛函理论(DFT)的第一性原理的平面波超软赝势方法,研究了Zr、Cu、Zn掺杂对VH2的电子结构和解氢性能的影响.计算结果显示Zr掺杂VH2后晶体模型的负合金形成热增加和费米能级Ef处电子浓度N(Ef)的减少,体系结构稳定性增强;V–H之间重叠集居数和电子密度计算也显示V–H之间相互作用增强;表明在VH2中掺杂Zr以后吸放氢最大容量增加,但解氢能力减弱.而Cu或Zn掺杂VH2以后晶体模型的负合金形成热减少和费米能级Ef处电子浓度N(Ef)的增加,体系结构稳定性减弱;V–H之间重叠集居数和电子密度计算也显示V–H之间相互作用减弱;表明在VH2中掺杂Cu或Zn以后吸放氢最大容量降低,但解氢能力增强.与实验结论相符.同时Mulliken集居数计算结果还显示V-d轨道Mulliken集居数与掺杂有关,掺杂Zr以后V-d轨道Mulliken集居数减少;掺杂Cu或Zn以后V-d轨道Mulliken集居数增加.
The effects of Zr, Cu and Zn doping on the electronic structure and hydrogen desorption performance of VH2 have been studied by the first-principles density functional theory (DFT) plane-wave ultra-soft pseudopotential method. The calculated results show that Zr-doped VH2 posterior crystal The increase of the negative alloy formation heat of the model and the reduction of the electron concentration N (Ef) at the Fermi level Ef increase the stability of the system structure. The calculation of the overlap population and the electron density between the V-Hs also shows that the V-Hs The results show that the maximum capacity of hydrogen storage and desorption increases after Zr doping in VH2, but the hydrogen desorption capacity is weakened.While the negative alloy formation heat of crystal model after Cu2 + or Zn2 doping VH2 decreases and the electron concentration N (Ef) increases, and the stability of the system is weakened. The calculation of the number of overlap clusters and the electron density between V-H also shows that the interaction between V-H is weakened. The results show that the Mulliken population number of Vd orbitals is related to doping, and the Mulliken population number of Vd orbitals decreases after doping with Zr. The doped Cu or After Zn Vd track Mulliken colonies increased.