Fe,Co,Ni掺杂石墨烯表面吸附C_2H_4的第一性原理研究

基于密度泛函理论(DFT)的广义梯度近似(GGA),本文对本征石墨烯以及掺杂Fe,Co,Ni石墨烯的几何结构和电子性质进行了优化计算,并计算了C_2H_4在本征石墨烯以及掺杂石墨烯表面的吸附过程,讨论了体系的吸附能、稳定性、DOS及掺杂对键长的影响.结果表明C_2H_4在本征石墨烯B位的吸附和掺杂石墨烯的吸附为化学吸附,在本征石墨烯T和H位的吸附为物理吸附;掺杂后石墨烯的比表面积增大,与本征石墨烯相比,掺杂使费米能级附近的态密度积分显著提高,表明掺杂石墨烯的电导性会发生变化,从而影响对C_2H_4的气敏度..C_2H_4在Fe、Co、Ni分别掺石墨烯的最佳吸附位为T位、H位和B位;掺杂Fe,Ni后体系的吸附能力显著提高,且掺杂Ni时体系的吸附能力最好.

First-principles study of C2H4 adsorption on Fe, Co and Ni doped graphene surface

Based on generalized gradient approximation (GGA) of density functional theory (DFT), geometric structure and electronic properties of the intrinsic graphene and the Fe,Co,Ni-doped graphene are optimized. Adsorption process of ethylene on the surface of the intrinsic and Fe,Co,Ni-doped graphene are calculated. Effects of adsorption energy, stability, DOS and doping on the bond length of the system are discussed. Results show that, the adsorption of ethylene on the intrinsic graphene B and doped graphene are chemisorbed while adsorption of intrinsic graphene T and H are physical adsorption. Compared with intrinsic graphene, DOS near the Fermi level is increased after doping, which greatly affects conductivity and gas sensitivity of graphene to ethylene. Optimal adsorption site of ethylene in Fe, Co, Ni-doped graphene is T, H,B, respectively, and energy of adsorption of doped-Ni system is the biggest.