▎ 摘　　要

We predict the CO2 gas molecule absorption and sensing performance of transitional MN4 (M = Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn) doped graphene by a systematic first-principles investigation based on density functional theory. Our results demonstrate that graphene doped with different transition metals, MN4, produce similar adsorption behaviors and electronic structures of carbon dioxide. We discovered that the TiN4 doped 4 x 4 graphene sheet (CO2/TiN4 G) is the most suitable candidate for carbon dioxide gas sensors. CO2/TiN4 G shows the strongest adsorption capability and the highest charge transfer between the TiN4 doped graphene sheet and carbon dioxide molecules for all the calculated systems. We conclude that TiN4 G can be designed for efficient CO2 gas sensors.