First-principle investigation of CO and CO2 adsorption on Fe-doped penta-graphene

Penta-graphene (PG) has many excellent properties, where the large surface-to-volume ratio and indirect band gap are conducive to the adsorption of gas molecules. In this paper, the adsorption behaviors of CO and CO2 on Fe-doped PG are investigated by calculating the adsorption energy, charge transfer, adsorption distance, electron density, density of states, and partial density of states from first principles. The results show that different adsorption orientations of CO and CO2 have different adsorption behaviors. Compared with CO2, CO generally exhibits better adsorption properties under same conditions. In addition, the doping of Fe atom at different sites will have different effects on the adsorption behavior of the system. The formation of chemical bonds between molecule and substrate is induced when the Fe atom is doped at the sp(2) hybridized carbon site. Our results are proposed to predict and understand the CO and CO2 adsorption properties of Fe-doped PG and would help in guiding experimentalists to develop better materials based on PG for efficient gas detection or sensing applications.