4d过渡金属掺杂石墨烯体系对NO_2分子的吸附  

Adsorption of NO_2 Molecule on 4d Transition Metal Doped Graphene

作　　者：董海宽[1,2] 齐义辉[2] 李明标[1] 修晓明[1] 史力斌[1] 

机构地区：[1]渤海大学数理学院,锦州121013 [2]辽宁工业大学材料科学与工程学院,锦州121001

出　　处：《人工晶体学报》2017年第2期304-310,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(11404033;11674037)

摘　　要：基于第一性原理的密度泛函理论对NO_2分子吸附在4d过渡金属掺杂的石墨烯体系进行了研究。发现Cd原子价电子构型为4d^(10)5s^2,形成饱和结构,不容易掺入石墨烯体系。调查了三种NO_2分子的吸附情况,分别是N原子、一个O原子、两个O原子靠近石墨烯体系吸附点。通过能量优化获得最稳定的吸附构型。通过吸附能、电荷转移等数据研究了各吸附构型对NO_2的吸附情况。纯的石墨烯体系对NO_2分子的吸附较弱,吸附能小于0.2 e V,而4d掺杂可以明显提高吸附体系的吸附性能,多数吸附能超过了2 e V。其中掺Nb原子对NO_2吸附效果最好,且吸附构型较稳定,吸附能为3.686 e V。此外,通过比较吸附前后带隙的变化,可发现掺Zr原子,石墨烯体系由半导体转变为金属,而掺Nb原子,石墨烯体系由金属转变为半导体。NO_2adsorption on graphene doped with 4d transition metal is investigated by the first principles based on density functional theory. It is observed that Cd atom cannot be doped into graphene due to saturated valence electron configurations of 4d^（10）5s^2. Three kinds of NO_2 adsorption configurations are investigated,in which N atom,one O atom and double O atoms in NO_2 are close to the adsorption site,respectively. The most stable adsorption configuration is obtained by total energy optimization. NO_2 adsorption can be studied by adsorption energy,charge transfer and other related data. The adsorption energy of NO_2 adsorption on pure graphene is less than 0. 2 e V. The adsorption ability is improved by doping 4d transition metal,and most of the adsorption energy is more than 2 e V. The effect of NO_2 adsorption on Nb doped graphene is very good,and the adsorption system is relatively stable with the adsorption energy of 3. 686 e V. Furthermore,by comparing the band structure change before and after NO_2 adsorption, it is observed that Zr doped graphene change from semiconductor to metal after adsorption of NO_2 molecule,and Nb doped graphene change from metal to semiconductor.

关 键 词：石墨烯 二氧化氮 4d过渡金属 吸附 

分 类 号：O647[理学—物理化学]