Hydrogen storage capacity of alkali metal atoms decorated porous graphene | |
Yuan Li-Hua1; Gong Ji-Jun1; Wang Dao-Bin1; Zhang Cai-Rong1; Zhang Mei-Ling1,3; Su Jun-Yan1; Kang Long2 | |
2020-03-20 | |
发表期刊 | Wuli Xuebao/Acta Physica Sinica |
ISSN | 10003290 |
卷号 | 69期号:6 |
摘要 | Porous graphene (PG), a kind of graphene-related material with nanopores in the graphene plane, exhibits novel properties different from those of pristine graphene, leading to its potential applications in many fields. Owing to periodic nanopores existing naturally in the two-dimensional layer, PG can be used as an ideal candidate for hydrogen storage material. High hydrogen storage capacity of Li-decorated PG has been investigated theoretically, but the effect of temperature on the stability of the H2 adsorbed on Li-PG has been not discussed yet. In this paper, by using the first-principles method, the hydrogen storage capacity on alkaline metal atoms (Li, Na, K) decorated porous graphene is investigated in depth with generalized gradient approximation, and the effect of the temperature on the stability of the hydrogen adsorption system is elucidated by the ab initio molecular-dynamics simulation. The results show that the most favorable adsorption sites of Li, Na and K are the hollow center sites of the C hexagon, and four alkaline metal atoms can be adsorbed stably on both sides of PG unit cell without clustering. Alkaline metal adatoms adsorbed on PG become positively charged by transferring charge to PG and adsorbed H2 molecules, and three H2 molecules can be adsorbed around each alkaline metal atom. By analyzing the Mulliken atomic populations, charge density differences and density of states of H2 adsorbed on Li-PG system, we find that the H2 molecules are adsorbed on alkaline metal atoms decorated graphene complex by attractive interaction between positively charged alkaline metal adatoms and negatively charged H and weak van der Waals interaction. Twelve H2 molecules are adsorbed on both sides of PG decorated with alkaline metal atoms. The average adsorption energy of H2 adsorbed on Li-PG, Na-PG and K-PG are -0.246, -0.129 and -0.056 eV/H2, respectively. It is obvious that the hydrogen adsorption capacity of Li-PG system is strongest, and the hydrogen adsorption capacity of K-PG is weakest, thus K-PG structure is not suitable for hydrogen storage. Furthermore, by the ab initio molecular-dynamic simulation, in which the NVT ensemble is selected but the external pressure is not adopted, the effect of temperature on the stability of H2 molecules adsorbed on Li-PG system is elucidated. The result shows that the configuration of Li-PG is very stable, H2 molecules are stably adsorbed around the Li atoms at low temperature, and some H2 molecules start to be desorbed from the Li atoms with the increase of temperature. At 200 K, H2 molecules begin to move away from Li atoms, and two H2 molecules escape from the binding of the Li atoms at 250 K. At 300 K, nine H2 molecules can be stably absorbed on both sides of Li-PG, and the gravimetric hydrogen storage capacity can reach up to 9.25 wt.%, which is much higher than the the US Department of Energy target value of 5.5 wt.% for the year 2017. With the increase of temperature, more adsorbed H2 molecules are desorbed, seven H2 molecules can be desorbed at 400 K, and all H2 molecules are completely desorbed in a temperature range of 600-700 K. © 2020 Chinese Physical Society. |
关键词 | Adatoms Atoms Desorption Flow of solids Gas adsorption Graphene Lithium Molecular dynamics Molecules Nanopores System stability Temperature Van der Waals forces Ab initio molecular dynamics Ab initio molecular dynamics simulation Charge density difference First principles method Generalized gradient approximations Hydrogen adsorption capacity Hydrogen storage capacities Van Der Waals interactions |
DOI | 10.7498/aps.69.20190694 |
收录类别 | SCI ; SCIE ; EI |
语种 | 中文 |
WOS研究方向 | Physics |
WOS类目 | Physics, Multidisciplinary |
WOS记录号 | WOS:000527803900029 |
出版者 | Institute of Physics, Chinese Academy of Sciences |
EI入藏号 | 20202108693861 |
EI主题词 | Hydrogen storage |
EI分类号 | 522 Gas Fuels - 542.4 Lithium and Alloys - 641.1 Thermodynamics - 761 Nanotechnology - 801.4 Physical Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 933 Solid State Physics - 961 Systems Science |
来源库 | Compendex |
分类代码 | 522 Gas Fuels - 542.4 Lithium and Alloys - 641.1 Thermodynamics - 761 Nanotechnology - 801.4 Physical Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 933 Solid State Physics - 961 Systems Science |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | https://ir.lut.edu.cn/handle/2XXMBERH/115455 |
专题 | 理学院 |
通讯作者 | Yuan Li-Hua |
作者单位 | 1.Lanzhou Univ Technol, Sch Sci, Lanzhou 730050, Peoples R China; 2.Lanzhou Univ Technol, Sch Mat Sci & Engn, Lanzhou 730050, Peoples R China; 3.Lanzhou Univ, Sch Nucl Sci & Technol, Lanzhou 730000, Peoples R China |
第一作者单位 | 理学院 |
通讯作者单位 | 理学院 |
第一作者的第一单位 | 理学院 |
推荐引用方式 GB/T 7714 | Yuan Li-Hua,Gong Ji-Jun,Wang Dao-Bin,et al. Hydrogen storage capacity of alkali metal atoms decorated porous graphene[J]. Wuli Xuebao/Acta Physica Sinica,2020,69(6). |
APA | Yuan Li-Hua.,Gong Ji-Jun.,Wang Dao-Bin.,Zhang Cai-Rong.,Zhang Mei-Ling.,...&Kang Long.(2020).Hydrogen storage capacity of alkali metal atoms decorated porous graphene.Wuli Xuebao/Acta Physica Sinica,69(6). |
MLA | Yuan Li-Hua,et al."Hydrogen storage capacity of alkali metal atoms decorated porous graphene".Wuli Xuebao/Acta Physica Sinica 69.6(2020). |
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