中国物理B ›› 2018, Vol. 27 ›› Issue (7): 76501-076501.doi: 10.1088/1674-1056/27/7/076501

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Co-adsorption of O2 and H2O on α-uranium (110) surface: A density functional theory study

Xin Qu(瞿鑫), Ru-Song Li(李如松), Bin He(何彬), Fei Wang(王飞), Kai-Long Yuan(袁凯龙)   

  1. Xi'an High Technology Institute, Xi'an 710025, China
  • 收稿日期:2017-11-24 修回日期:2018-04-02 出版日期:2018-07-05 发布日期:2018-07-05
  • 通讯作者: Ru-Song Li E-mail:rusong231@126.com
  • 基金资助:
    Project supported by the National Nature Science Foundation of China (Grant Nos. 51401237, 11474358, and 51271198).

Co-adsorption of O2 and H2O on α-uranium (110) surface: A density functional theory study

Xin Qu(瞿鑫), Ru-Song Li(李如松), Bin He(何彬), Fei Wang(王飞), Kai-Long Yuan(袁凯龙)   

  1. Xi'an High Technology Institute, Xi'an 710025, China
  • Received:2017-11-24 Revised:2018-04-02 Online:2018-07-05 Published:2018-07-05
  • Contact: Ru-Song Li E-mail:rusong231@126.com
  • Supported by:
    Project supported by the National Nature Science Foundation of China (Grant Nos. 51401237, 11474358, and 51271198).

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摘要： First-principles calculations based on density functional theory corrected by Hubbard parameter U (DFT+U) are applied to the study on the co-adsorption of O2 and H2O molecules to α-U(110) surface. The calculation results show that DFT+U method with Ueff=1.5 eV can yield the experimental results of lattice constant and elastic modulus of α-uranium bulk well. Of all 7 low index surfaces of α-uranium, the (001) surface is the most stable with lowest surface energy while the (110) surface possesses the strongest activity with the highest surface energy. The adsorptions of O2 and H2O molecules are investigated separated. The O2 dissociates spontaneously in all initial configurations. For the adsorption of H2O molecule, both molecular and dissociative adsorptionsoccur. Through calculations of co-adsorption, it can be confirmed that the inhibition effect of O2 on the corrosion of uranium by water vapor originates from the preferential adsorption mechanism, while the consumption of H atoms by O atoms exerted little influence on the corrosion of uranium.

关键词: co-adsorption, α-U(110) surface, DFT+U, inhibition mechanism

Abstract: First-principles calculations based on density functional theory corrected by Hubbard parameter U (DFT+U) are applied to the study on the co-adsorption of O2 and H2O molecules to α-U(110) surface. The calculation results show that DFT+U method with Ueff=1.5 eV can yield the experimental results of lattice constant and elastic modulus of α-uranium bulk well. Of all 7 low index surfaces of α-uranium, the (001) surface is the most stable with lowest surface energy while the (110) surface possesses the strongest activity with the highest surface energy. The adsorptions of O2 and H2O molecules are investigated separated. The O2 dissociates spontaneously in all initial configurations. For the adsorption of H2O molecule, both molecular and dissociative adsorptionsoccur. Through calculations of co-adsorption, it can be confirmed that the inhibition effect of O2 on the corrosion of uranium by water vapor originates from the preferential adsorption mechanism, while the consumption of H atoms by O atoms exerted little influence on the corrosion of uranium.

Key words: co-adsorption, α-U(110) surface, DFT+U, inhibition mechanism

中图分类号:  (Surface energy)

  • 65.40.gp
68.35.-p (Solid surfaces and solid-solid interfaces: structure and energetics) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)