Theoretical investigation of the surface orientation impact on the hydrogen vacancy formation of MgH2
作者:Chen, WY (Chen, Wan-Yu)[ 1 ] ; Tang, JJ (Tang, Jia-Jun)[ 2 ] ; Lu, ZW (Lu, Zhi-Wei)[ 1 ] ; Huang, MX (Huang, Meng-Xia)[ 1 ] ; Liu, L (Liu, Lu)[ 1 ] ; He, CC (He, Chang-Chun)[ 1 ] ; Zhao, YJ (Zhao, Yu-Jun)[ 1,3 ]
SURFACE SCIENCE
卷: 710
文献号: 121850
DOI: 10.1016/j.susc.2021.121850
出版年: AUG 2021
文献类型:Article
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摘要
MgH2 is one of the most promising materials for solid-state hydrogen storage, but its slow kinetics and relatively high dehydrogenation temperature have yet to be overcome. We have theoretically investigated surface energy and surface H vacancy formation on various MgH2 surfaces, including all possible H vacancy configurations in the studied size of MgH2(110), (100), (101), and (001), up to (3 x 2), (2 x 3), (2 x 2) and (2 x 2) slabs respectively, based on density functional theory. Consequently, the hydrogen diffusion paths on the surfaces are also studied. The most unstable surface, MgH2(001), has the most drastic change in vacancy formation energy. The relative high barriers for vacancy H formation, especially on the most stable surface, MgH2(110), reflect the slow kinetics of H release. The introduction of vacancy into MgH2 surfaces often induces defect levels in the energy-gap region. In general, the release of surface H atoms exhibits a pronounced dependence on the surface stability and the concentration of surface H vacancy, in line with the remarkable effect of ball milling in experiments.
关键词
作者关键词:Hydrogen vacancy formation; MgH2; Ab initio calculation; Surface effect
KeyWords Plus:STORAGE PROPERTIES; AB-INITIO; DESORPTION; MAGNESIUM; DEHYDROGENATION; KINETICS; SORPTION; ADSORPTION; DIFFUSION; DEFECTS
作者信息
通讯作者地址:
South China University of Technology South China Univ Technol, Dept Phys, Guangzhou 510640, Peoples R China.
South China University of Technology South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China.
通讯作者地址: Zhao, YJ (通讯作者)
显示更多 South China Univ Technol, Dept Phys, Guangzhou 510640, Peoples R China.
通讯作者地址: Zhao, YJ (通讯作者)
显示更多 South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China.
地址:
显示更多 [ 1 ] South China Univ Technol, Dept Phys, Guangzhou 510640, Peoples R China
显示更多 [ 2 ] Guangdong Univ Technol, Sch Chem Engn & Light Ind, Inst Nat Med & Green Chem, Guangzhou 510006, Peoples R China
显示更多 [ 3 ] South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China
电子邮件地址:zhaoyj@scut.edu.cn
基金资助致谢
基金资助机构显示详情 授权号
National Natural Science Foundation of China (NSFC)
51621001
National Natural Science Foundation of China (NSFC)
12074126
U1601212
National Natural Science Foundation of Guangdong Province
2016A030312011
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出版商
ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS
期刊信息
Impact Factor (影响因子): Journal Citation Reports
类别 / 分类
研究方向:Chemistry; Physics
Web of Science 类别:Chemistry, Physical; Physics, Condensed Matter