Adsorption of NH3 and NO2 molecules on the carbon doped C3N monolayer: A first principles study

In this work, we investigated the optimized structures and electronic properties of novel C3N monolayers doped with carbon atoms at the central hexagon site. The C3N monolayer is an indirect band gap semiconductor with a small band gap at the Fermi level. After substituting carbon atoms, the electronic properties and structures of the nanosystems can be modulated. Interestingly, the new carbon doped C3N structure shows semiconducting behavior. The total electron density profiles show the distribution of charge densities over the whole domain doped nanostructures. The adsorption energy of NO2 molecule on the doped C3N system is higher than that of NH3 molecule, indicating that NO2 molecule strongly interacts with the C3N system. The electron density difference plots show that the charge densities were mainly accumulated at the central carbon doped hexagon site. Both NH3 and NO2 gas molecules are weakly adsorbed on the carbon substituted C3N monolayers.