Abstract: NO2 adsorption 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 4d10 5s2.Three kinds of NO2 adsorption configurations are investigated,in which N atom,one O atom and double O atoms in NO2 are close to the adsorption site,respectively.The most stable adsorption configuration is obtained by total energy optimization.NO2 adsorption can be studied by adsorption energy,charge transfer and other related data.The adsorption energy of NO2 adsorption on pure graphene is less than 0.2 eV.The adsorption ability is improved by doping 4d transition metal,and most of the adsorption energy is more than 2 eV.The effect of NO2 adsorption on Nb doped graphene is very good,and the adsorption system is relatively stable with the adsorption energy of 3.686 eV.Furthermore,by comparing the band structure change before and after NO2 adsorption,it is observed that Zr doped graphene change from semiconductor to metal after adsorption of NO2 molecule,and Nb doped graphene change from metal to semiconductor.

Key words: NO2 adsorption 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 4d10 5s2.Three kinds of NO2 adsorption configurations are investigated,in which N atom,one O atom and double O atoms in NO2 are close to the adsorption site,respectively.The most stable adsorption configuration is obtained by total energy optimization.NO2 adsorption can be studied by adsorption energy,charge transfer and other related data.The adsorption energy of NO2 adsorption on pure graphene is less than 0.2 eV.The adsorption ability is improved by doping 4d transition metal,and most of the adsorption energy is more than 2 eV.The effect of NO2 adsorption on Nb doped graphene is very good,and the adsorption system is relatively stable with the adsorption energy of 3.686 eV.Furthermore,by comparing the band structure change before and after NO2 adsorption,it is observed that Zr doped graphene change from semiconductor to metal after adsorption of NO2 molecule,and Nb doped graphene change from metal to semiconductor.