CO2 gas adsorption into graphene oxide framework: Effect of electric and magnetic field

Abstract Effect of external field on CO2 adsorption into graphene oxide framework (GOF) was studied by molecular dynamics simulation. Two regimes of electric and magnetic field in parallel or perpendicular to the linker direction of the GOF were applied. The major changes in CO2 uptake occurs when a strong electric field is applied on the GOF. Magnetization in the both parallel and perpendicular to the linker direction does not affect significantly on adsorption capacity. Results of radial distribution function and potential of mean force showed that the highest CO2-GOF affinity and adsorption energy is responsible for the highest adsorption capacity. A combined radial and angular distribution function analysis showed that a compact perpendicular ordering near the linker is responsible not only for the increase in gas capacity of the GOF by applying strong electric field in the parallel to the linker direction but also diffusion coefficient and transition time from ballistic to Fickian. Furthermore, adsorption capacity of non-treated and magnetized system is affected by temperature; however, applying a stong electric field on the system leads to an insignificant change by temperature variation. It was also observed that increasing electric field leads to increasing the adsorption capacity by an approximately linear correlation. Applying electric field increases selectivity of the CO2.