Tuning of adsorption energies of CO2 and CH4 in borocarbonitrides BxCyNz: A first-principles study.

We present density functional theory based calculations with semiempirical dispersion (DFT-D) analysis of CO2, CH4, N2 and H2 adsorption at various sites of 2-dimensional BCN with various chemical ordering of B, C and N and also on graphene and C-BN arm-chair interface of BC2N having graphene and BN domains. We find BCN and BC2N shows greater ability to absorb these gases as compared to graphene. CO2 binds strongly as compared to other gases with optimum storage of 44 wt% for a monolayer of BCN. A significant new result is that when BC2N sheets are doped with boron they show significant increase in adsorption energies for CO2 and CH4. Through the present work, we propose a way to tune adsorption energies of CO2 and CH4 by changing the doping concentration of boron.