Y掺杂空位石墨烯对NO及CO气体表面吸附的第一性原理研究

The study of CO and NO surface adsorption on Y-doped vacancy graphene through first-principles Method

基于第一性原理的计算方法,建立了本征石墨烯、空位石墨烯及钇(Y)掺杂空位石墨烯模型,并计算了CO、NO在三类石墨烯表面的吸附过程.从表面能、吸附结构、吸附能和态密度四个方面进行分析讨论,研究掺杂Y对CO、NO气体吸附性能的影响.结果表明:CO、NO与本征石墨烯之间的吸附为弱的物理吸附,掺杂Y后增强了材料表面对CO、NO的吸附效果,最大吸附能分别为7.414 eV、6.702 eV,属于化学吸附;掺杂Y使空位石墨烯费米能级附近有了更多的活跃电子,其吸附NO后体系由半金属转变为金属特性,该特性能为开发更加优良的石墨烯气敏材料提供理论支持.

Based on the First-principle calculation method, the models of intrinsic graphene, vacancy graphene and yttrium(Y) doped vacancy graphene were established. The adsorption processes of CO and NO on the surface of the above mentioned three types of graphene were calculated. The influence of doping Y on the adsorption performance of CO and NO gas was studied from surface energy, adsorption structure, adsorption energy and state density. The results showed that the adsorptions of CO, NO on intrinsic graphene are weak physical adsorptions. After Doping Y, the adsorption effect of CO and NO on its surface are markedly enhanced, and the maximum adsorption energies are 7.414 eV and 6.702 eV respectively, and the adsorption type changed to chemical adsorption. The doping Y increases the number of active electrons near the Fermi level of the vacancy graphene, and the system changes from semi-metal to metal after NO adsorption, which can provide theoretical support for the development of better graphene gas sensitive materials.