(華北理工大學(xué) 機(jī)械工程學(xué)院，唐山 063210)
摘 要: 采用第一性原理方法研究了本征石墨烯、硼摻雜石墨烯、空位缺陷石墨烯、空位硼摻雜石墨烯對Co2+離子的吸附作用。通過計(jì)算、分析上述不同石墨烯模型吸附Co2+后幾何結(jié)構(gòu)、吸附能、電荷轉(zhuǎn)移量及能帶結(jié)構(gòu)的變化，發(fā)現(xiàn)本征石墨烯與Co2+雖能發(fā)生吸附，但吸附效果差；硼摻雜與空位缺陷使石墨烯與Co2+之間的吸附能增大，并使石墨烯能帶產(chǎn)生帶隙，顯著提高了石墨烯對Co2+的吸附性。吸附后的體系態(tài)密度分析表明，三種改性石墨烯均與Co2+的態(tài)密度曲線發(fā)生明顯重疊，表明相互之間發(fā)生了化學(xué)吸附。其中空位缺陷石墨烯對Co2+的吸附性能最優(yōu)，其次是空位硼摻雜石墨烯，表明空位缺陷石墨烯和空位硼摻雜石墨烯可作為Co2+的檢測和吸附去除材料。
關(guān)鍵字: 石墨烯；空位缺陷；摻雜；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
