First-principles investigation of CO and CO2 adsorption on pristine and Fe-doped planar carbon allotrope net-Y

Abstract

A new planar carbon allotrope named net-Y with periodic four-six-eight-membered carbon rings has been synthesized in the experiment. In this paper, the adsorption properties of CO and CO2 on the intrinsic net-Y and two Fe-doped net-Y surfaces were studied by first-principles calculations. Using adsorption energy, charge transfer, adsorption distance, charge density and density of state, it can be found that the adsorption of CO and CO2 on the intrinsic net-Y surface appears as physisorption with weak interaction. Based on this, in order to enhance the adsorption strength of CO and CO2 on the surface of net-Y, Fe-doping is performed on net-Y. The calculation results after doping show that the doping of Fe atoms at different positions can significantly improve the adsorption strength of the two gas molecules. After CO and CO2 are adsorbed on the doped net-Y surface, the adsorption energy is greatly improved compared with the intrinsic adsorption energy, which makes the two gas molecules form a chemical bond with the substrate. Subsequent, the results of charge density and density of state further prove that the adsorption system shows chemisorption with strong interaction. Comparing doped and intrinsic adsorption, after Fe doping, the adsorption of CO and CO2 is stronger, which makes it possible to be effectively used for the adsorption and removal of CO and CO2 gas.