摘要
3d过渡金属修饰是改善石墨烯储氢性能的最有效途径,但仍存在金属团聚和H_(2)解离导致难以脱附的问题.提出了B/N掺杂单缺陷石墨烯(BMG/NMG)的策略来避免以上两个问题.密度泛函理论计算结果表明,N掺杂可以使Sc,Ti,V与石墨烯的结合能提高3~4倍,B掺杂可以将Sc与石墨烯的结合能提高3倍.Sc/BMG和Sc/NMG吸附的第一个H_(2)不会解离.Sc/BMG中Sc吸附5个H_(2),平均氢分子结合能为−0.18~−0.43 eV,并且可以通过在同侧锚定多个Sc原子形成Sc/C3B2五元环增加H_(2)吸附位点.Sc/NMG中每个Sc吸附6个H_(2),平均氢分子结合能为−0.17~−0.29 eV,还可以通过在异侧修饰形成Sc/N3/Sc单元进一步提高储氢能力.研究结果将为设计基于3d过渡金属修饰碳材料的储氢材料提供理论基础.
3d Transition-metal decorating is the most effective way to improve the hydrogen storage performance of graphene.However,metal agglomeration and dissociation of H_(2)greatly limit their application.In this paper,B/N doping was proposed to avoid the above two problems.Density functional theory calculations show that the binding energy of Sc can be greatly increased by B/N doping.Both Sc/BMG and Sc/NMG can be used as potential hydrogen storage materials because the first adsorbed H_(2)is molecular.Sc/BMG could adsorb 5H_(2)with the average hydrogen adsorption energy of−0.18─−0.43 eV.The H_(2)adsorption sites of BMG could be increased by forming multiple Sc/C_(3)B+(2) units.Sc/NMG could adsorb 6H_(2)with the average hydrogen adsorption energy of−0.17-0.29 eV.The hydrogen storage capacity of Sc/NMG could be further improved by the formation of Sc/N3/Sc units.
作者
马丽娟
高升启
荣祎斐
贾建峰
武海顺
MA Lijuan;GAO Shengqi;RONG Yifei;JIA Jianfeng;WU Haishun(Key Laboratory of Magnetic Molecules&Magnetic Information Materials,Ministry of Education,School of Chemical and Material Science,Shanxi Normal University,Linfen 041004,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第9期2842-2851,共10页
Chemical Journal of Chinese Universities
基金
国家自然科学基金青年科学基金(批准号:21805176)
山西省青年科技研究基金(批准号:201901D211394)
山西省研究生创新项目(批准号:2020SY332)
山西师范大学校级创新项目(批准号:2020XSY030,2020XSY002)资助.
关键词
储氢
硼/氮掺杂
单缺陷石墨烯
过渡金属
密度泛函理论
Hydrogen storage
B/N-doped
Monovacancy graphene
3d Transition metal
Density functional theory
