氟和钛共同掺杂对NaMgH3放氢性能的影响

采用基于密度泛函理论(DFT)的平面波赝势(PW-PP)方法，探讨Ti阳离子与F阴离子共同掺杂对氢化物NaMgH3放氢性能影响的内在机制。在F阴离子掺杂替代氢化物中的部分氢提高体系放氢性能的基础上，用Ti取代Na4Mg4H11F中的部分Na。电子结构分析显示，F和Ti共掺杂后，氢的1s能级与Ti的3d能级强的交互作用导致原来靠近费米能级的氢的能级分为两部分：一部分左移远离费米能级；另一部分右移恰好跨越费米能级。同没有掺杂的NaMgH3相比，氢在氢化物中的稳定性降低，有利于氢化物的放氢

Effects of Fluorine and Titanium Codoping on Hydrogen Desorption Properties of Hydride NaMgH3

The intrinsic mechanism of effects of Ti and F ions codoping on the dehydrogenating properties of the NaMgH3 hydrides was investigated by means of a plane-wave pseudopotential (PW-PP) method based on the density functional theory (DFT). The doped F ion replace some of hydrogen in the hydride to increase the hydrogen desorption properties of the system and subsequently Ti ions substitute for some of Na in Na4Mg4H11F. The electronic structure analysis shows that the strong interactions between H and metals (especially H-1s and Ti-3d) result in a split of the hydrogen energy level near the Fermi energy (EF) level. One part shifts to the left apart from the EF level while the other part shifts to the right over the EF level. The stability of hydrogen in the doped hydride is decreased compared with that in the NaMgH3 hydride without doping, thus improving the hydrogen desorption performance of the hydride