碱金属与石墨烯间的吸附性能及电子性质的研究

Study on the adsorptive and electronic properties between alkali metals and graphene

碱金属/石墨烯体系在纳米器件、锂离子电池等领域具有重要的应用价值。采用基于密度泛函理论(DFT)的第一性原理方法研究了碱金属与石墨烯间的吸附性能及电子性质。研究表明,锂、钠、钾吸附在碳环中心(H位置)的平衡距离分别为0.175nm、0.223nm和0.263nm,相应的吸附能E锂>E钾>E钠。吸附过程中碱金属与石墨烯间发生电荷转移,体系的电偶极矩发生变化。锂和钾吸附后HOMO^LUMO能隙变大,相比锂和钾,钠与石墨烯间的吸附最弱。

Alkali metals and graphene system has important application in the field of nano device and lithium ion batteries.The first-principles method based on density functional theory（DFT）was used to study the adsorptive and electronic properties between Li,Na,K and graphene.The study shown that the equilibrium distance was 0.175 nm,0.223 nm and 0.263 nm,respectively when Li,Na,K adsorption at the center of the carbon ring（H position）and the corresponding adsorption energy ELi〉EK〉ENa.Charge transfer occured between alkali metals and graphene and the electric dipole moment changed in the process of adsorption.The HOMO-LUMO gap became larger after Li and K adsorption.Compared to Li and K,the adsorption was the weakest between Na and graphene.