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采用密度泛函理论广义梯度近似平面波赝势法结合周期平板模型,研究F离子在γ-Al_2O_3(110)非极性表面的吸附行为,分析了F~-离子在其表面不同吸附位以及不同覆盖度下吸附构型和电子特性。结果表明:表面配位不饱和的Al为F~-离子活性吸附位,F离子在γ-Al_2O_3(110)表面化学吸附后形成F-Al键促使F~-离子活化;F~-离子在Al_Ⅲ(1)桥位吸附时最稳定。随着覆盖度增加,吸附能增大,F离子与表层原子的距离(d_(F~--surf)缩短:同时表面吸附F离子引起表层及次表层原子层间距发生不同程度偏移,最大幅度为10.07%。差分电荷密度与电子态密度分析指出,F离子在γ-Al_2O_3(110)表面吸附主要是由F~-离子2s和2p轨道与γ-Al_2O_3基底Al的3p轨道相互作用所致。
The adsorption behavior of F ions on γ-Al 2 O 3 (110) nonpolar surface was studied by using density functional theory (GPD) generalized gradient approximation plane wave pseudopotential method and periodic slab model. The adsorption sites of F ~ - ions on the surface of γ- Degree of adsorption configuration and electronic properties. The results show that Al is F - ion active adsorption site on the surface, and F - Al bond is formed on the surface of γ - Al_2O_3 (110) (1) The most stable adsorption site bridge. As the coverage increases, the adsorption energy increases and the distance between the F ions and the surface atoms decreases (d_ (F ~ -surf)). At the same time, the adsorption of F ions on the surface causes the atomic layer spacing of the surface layer and the subsurface layers to shift to different extents. The maximum amplitude Is 10.07% .Analysis of difference charge density and electron density shows that the adsorption of F ions on γ-Al 2 O 3 (110) surface is mainly caused by the interaction of 2p and 2p orbitals with 3p orbital of γ-Al 2 O 3 substrate.