科研之友
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摘要
First-principles calculation on the basis of the density functional theory (DFT) and generalized gradient approximation have been applied to study the adsorption of H(2) on the stoichiometric O-terminated Cu(2)O (1 1 1), Cu(2)O (1 1 1)-Cu(CUS) and Cu-terminated Cu(2)O (1 1 1) surfaces. The optimal adsorption position and orientation of H(2) on the stoichiometric O-terminated Cu(2)O (1 1 1) surface and Cu-terminated Cu(2)O (1 1 1) surface were determined and electronic structural changes upon adsorption were investigated by calculating the Local Density of States (LDOS) of the Cu(CUS) 3d and Cu(CUS) 4s of stoichiometric O-terminated Cu(2)O (1 1 1) surface. These results showed that H(2) molecule adsorption on Cu(CUS) site parallel to stoichiometric O-terminated Cu(2)O (1 1 1) surface and H(2) molecule adsorption on Cu(2) site parallel to Cu-terminated Cu(2)O (1 1 1) surface were the most favored, respectively. The presence of surface copper vacancy has a little influence on the structures when H(2) molecule adsorbs on Cu(CSA), O(CUS) and O(CSA) atoms and the H(2) molecule is only very weakly bound to the Cu(2)O (1 1 1)-Cu(CUS) surface. From the analysis of stoichiometric O-terminated Cu(2)O (1 1 1) Local Density of States, it is observed that Cu(CUS) 3d orbital has moved to a lower energy and the sharp band of Cu(CUS) 4s is delocalized when compared to that before H(2) molecule adsorption, and overlapped substantially with bands due to adsorbed H(2) molecule. The Mulliken charges of H(2) adsorption on Cu(CUS) site showed that H(2) molecule obtained electron from Cu(CUS) which was consistent with the calculated electronic structural changes upon H(2) adsorption.
- 出版日期2011-10-1
- 单位北京航空航天大学
