摘要
本文基于密度泛函理论(DFT)方法,提出了一种基于钴和铜原子的二维金属有机框架(MOF)。通过声子谱的计算发现没有出现虚频率,验证了MOF晶体结构的稳定性。基于电子能带结构的计算,通过施加外电场,可以发现Cu基MOF始终保持金属的特性。然而,Co基MOF在外电场作用下会发生从金属到半导体的转变。当电场强度达到0.5 eV/时,Co基MOF的带隙约为0.1 eV,而Cu基MOF则不会出现这种情况。此外,还研究了Co基MOF对N_(2)的吸附和氮还原反应(NRR),结果表明Co基MOF的NRR表现良好,电场可以增强NRR的效果。在0.5 eV/的外电场下,自由能比没加外电场的时候低0.51 eV。本文的理论计算有助于实验上MOF的NRR过程设计。
Based on density functional theory(DFT),a two-dimensional(2D)metal-organic framework(MOF)based on Co and Cu atoms were presented.Based on the phonon dispersion calculations,no imaginary mode is found in the phonon branches,which verifies that the crystal structures of MOF could be stable.Based on the calculation of electronic band structure,it is found that the Cu-based MOF is a metallic system by applying external electric field.While the Co-based MOF undergoes a transition from metal to semiconductor under external electric field.When the external electric field intensity reaches up to 0.5 eV/,the band gap of Co-based MOF is around 0.1 eV,while this does not happen in the Cu-based MOF.Furthermore,the N_(2)adsorption and the nitrogen reduction reaction(NRR)were investigated for the Co-based MOF,which shows that the NRR for the Co-based MOF exhibits good performance,and the electric field could enhance this effect of NRR.The free energy of NRR under external electric field of 0.5 eV/is 0.51 eV lower than that without electric field.Therefore,our study would prospectively guide the experimental researchers on the design of NRR.
作者
杨燕
王献朗
陈昊天
卢浩
佘世雄
黄智昊
YANG Yan;WANG Xianlang;CHEN Haotian;LU Hao;SHE Shixiong;HUANG Zhihao(College of Chemical Engineering,Qinghai University,Xining 810016,China;Department of Materials Science and Engineering,City University of Hong Kong,Hong Kong 999077,China)
出处
《人工晶体学报》
CAS
北大核心
2024年第10期1752-1758,共7页
Journal of Synthetic Crystals
基金
青海省自然科学基金(2020-ZJ-742)
国家自然科学基金(22164017)。
