Adsorption of H2, N2, CO, H2S, NH3, SO2and CH4on Li-functionalized graphitic carbon nitride investigated by density functional theory

The interaction of small gas molecules as H-2, N-2, CO, H2S, NH3, SO(2)and CH(4)on Li-functionalized graphitic carbon nitride was investigated by using the density functional theory, to explore their gas adsorption properties. The calculatedE(ads)values of all gas molecules on [Li g-C3N4](+)show that these gas molecules present favourable interaction with the lithium atom coordinated on the sheet. NH(3)and SO(2)molecules present strong interactions, withE(ads)values of -18.60 and -9.50 kcal mol(-1). The natural bond orbital analysis indicates that donor orbitals belong to the lone pairs of oxygen, nitrogen, sulphur and carbon atoms from SO2, N-2, NH3, H2S, CO molecules, and acceptor orbitals (LP*) from the lithium atom. Computational studies suggest that H-2, N-2, CO, H2S, NH3, SO(2)and CH(4)molecules on [Li g-C3N4](+)present physisorption.