▎ 摘　　要

Developing advanced materials and new technologies for efficient CO2 capture and gas separation can enormously alleviate its impact on global climate change. In this study, we report a comprehensive density functional theory investigation of N-2, CH4, H-2, and CO2 adsorption on a graphene-like C3N monolayer. Our calculation results show that the four gas molecules are all physisorbed on the neutral C3N monolayer. However, the interaction between CO2 and C3N can be significantly boosted via the strategies of electrochemical methods such as introducing negative charge or applying external electric field to the system. While the adsorption of N-2, CH4 and H-2 on C3N monolayer is slightly influenced with the above strategies. Moreover, CO2 will release spontaneously from C3N monolayer once the extra charge or electric field is removed from the system. These results demonstrate that the CO2 capture, regeneration and separation on C3N monolayer can be controllable with the method of switching on/off the charge state or electric field during the adsorption. In addition, as a new synthesized 2D material (PNAS, 2016, 113, 7414-7419), C3N possesses an extremely narrow band gap of 0.39eV, which guarantees applying negative charge or electric field to it can be easily realized in experiment by electrochemical methods.