Adsorption of alkali metal atoms on predicted C3N2 sheet

Two-dimensional C3N2 was predicted to become stable using structure searching simulations. In view of the planar porous structure, two-dimensional C3N2 is likely to absorb alkali metal such as Li, Na and K, and the electronic properties of two-dimensional C3N2 could be modified by atomic adsorption. In this work, the effects of adsorption of alkali metal atoms on the monolayer C3N2 structure were systematically investigated. Our current results uncovered that the adsorbing ability of Li is stronger than that of Na as evidenced by the lower negative formation energy. Moreover, the adsorption of alkali metal atoms can efficiently influence the electronic properties of monolayer C3N2 with the modification from semiconductor to metal. •The adsorption energy of Li was the lowest one, and the scale of adsorption energy decreases with increase of atomic radius.•The electronic properties of C3N2 were significantly modified by adsorption of alkali metal atoms.•We uncovered that the elements with small atomic radius may be more easily adsorbed on 2D carbon nitride materials.