A first-principles investigation of double transition metal atoms embedded C2N monolayer as a promising SF6 gas adsorbent and scavenger

Abstract

Greenhouse effect has become one of the most rigorous topics of environmental protection. The emission of one of the most typical greenhouse gas SF6 should be controlled and the waste gas treatment of SF6 has become a major topic to reduce the greenhouse effect. Two-dimensional porous materials have been widely used in gas adsorption and separation which may be useful for adsorbing waste SF6 gas. In this study, we report a promising adsorbent, transition metal dimer decorated C2N monolayer, for SF6 treatment by theoretical evaluation. The adsorption of SF6 molecule over the C2N surface are explored including the adsorption energy, electron transfer, magnetic moment and the electronic properties. Also, the decomposition process of SF6 molecule over the TM2-C2N monolayer is also considered. The results show that the SF6 can only be physical adsorption over the pristine C2N monolayer and experiences obvious decomposition over the Co2–C2N and Ni2–C2N monolayer. The adsorption with molecule decomposition can also significantly change the electronic properties of TM2-C2N. The low energy barrier of decomposition process over the TM2-C2N ensures good performance of adsorbent for SF6 in practical applications. This study provides theoretical foundation for TM2 dimer C2N monolayer as a promising adsorbent, scavenger and even catalytic material for degradation of greenhouse gas SF6 and waste gas treatment.