(华北理工大学 机械工程学院，唐山 063210)
摘 要: 采用第一性原理方法研究了本征石墨烯、硼掺杂石墨烯、空位缺陷石墨烯、空位硼掺杂石墨烯对Co2+离子的吸附作用。通过计算、分析上述不同石墨烯模型吸附Co2+后几何结构、吸附能、电荷转移量及能带结构的变化，发现本征石墨烯与Co2+虽能发生吸附，但吸附效果差；硼掺杂与空位缺陷使石墨烯与Co2+之间的吸附能增大，并使石墨烯能带产生带隙，显著提高了石墨烯对Co2+的吸附性。吸附后的体系态密度分析表明，三种改性石墨烯均与Co2+的态密度曲线发生明显重叠，表明相互之间发生了化学吸附。其中空位缺陷石墨烯对Co2+的吸附性能最优，其次是空位硼掺杂石墨烯，表明空位缺陷石墨烯和空位硼掺杂石墨烯可作为Co2+的检测和吸附去除材料。
关键字: 石墨烯；空位缺陷；掺杂；吸附；Co2+；第一性原理
（College of Mechanical Engineering, North China University of Science and Technology, Tangshan 063210, China）
Abstract:On the basis of first-principles calculation, the adsorption performance of Co2+ ions on pristine graphene, boron-doped graphene, vacancy-defected graphene, and boron-doped vacancy-defected graphene was investigated. By computing and analyzing the geometric structure, adsorption energy, charge transfer and band structure of the above mentioned four types of graphene after Co2+ adsorption, we can find that although there exists an adsorption interaction between pristine graphene and Co2+, the effect of the adsorption is poor. Both boron doping and vacancy defects can increase the adsorption energy between graphene and Co2+, and result in a bandgap in the band structure of graphene, greatly enhancing the adsorption effect of graphene to Co2+. Analysis on the density of states of the adsorption system of graphene and Co2+ demonstrates that there is a strong coupling between Co2+ and the three types of modified graphene, indicating the occurrence of chemical adsorption between them. Among the three types of modified graphene, the vacancy-defected graphene has the strongest adsorption to Co2+, followed by boron-doped vacancy-defected graphene. This indicates that vacancy-defected graphene and boron-doped vacancy-defected graphene can be used for detecting and removing Co2+ ions by adsorption.
Key words: graphene; vacancy defect; doping; adsorption; Co2+; first principles
