氮掺杂单层石墨烯储钠性能的第一性原理研究

First principle calculations on Na storage on the surface of N doped monolayer graphene

采用密度泛函理论(DFT)的第一性原理方法,对Na在本征石墨烯和不同掺杂浓度的N掺杂石墨烯(NG)表面的吸附性质进行了研究。确定了不同N掺杂浓度时NG的最稳定N分布结构,计算了Na在PG和不同掺杂浓度的NG表面的吸附能。计算结果表明,N原子掺杂倾向于取代对位或次临近位置的C原子;随着N掺杂浓度的增加,吸附高度逐渐增加,且与N掺杂分布相匹配;N掺杂浓度大于C∶N=2∶1(摩尔数比)时,Na在NG表面的吸附相对稳定,Na与C_9N_9表面的结合最稳定。

The adsorption properties of Na on the surface of pristine graphene(PG)and N doped graphene(NG)with different doping concentrations were studied by using the first principles method based on density functional theory(DFT).The most stable N distribution structures of NG at different N doping concentrations were determined,and the adsorption energies of Na on the surface of PG and NG with different doping concentrations were calculated.The results revealed that doping N atoms tend to replace the C atoms at the para or sub-adjacent positions.With the increase in the N doping concentration,the adsorption heights increase gradually and match the distribution for doping N atoms.When the N doping concentration is larger than C∶N=2∶1(molar ratio),Na adsorption on the NG surface is more stable,and the binding between Na and the surface of C_9N_9 is the most stable.