Comment on 'Two-dimensional carbon nitride C 6 N nanosheet with egg-comb-like structure and electronic properties of a semimetal [2021, Nanotechnology 32 , 215702]'.

Recently, Bafekry et al (2021 Nanotechnology 32 215702) predicted a novel two-dimensional carbon nitride with an egg-comb-like structure and a C 6 N stoichiometry. Their density functional theory results reveal the thermal stability of this structure at 300 K. They also examined the thermoelectric properties of this monolayer up to 500 K. By adopting the same methodology employed in the original work by Bafekry et al (2021 Nanotechnology 32 215702), we show that this monolayer is thermally unstable and cannot be employed for practical applications. Aforementioned theoretical work also includes inaccuracies in the evaluation of thermoelectric properties of the C 6 N monolayer, as they did not consider the contribution of the lattice thermal conductivity.