Incorporation of Hydrogen Molecules into Carbon Nitride Heterofullerenes: An Ab Initio Study

The possibility of the formation of endohedral complexes between H-2 molecules and carbon nitride heterofullerenes, C48N12, C44N6 and C33N9, was investigated by using the density functional theory (DFT) calculations. We find that up to two H-2 molecules being incorporated inside the cage can form the stable complex with C-60 and C48N12 fullerenes while for the others only one hydrogen molecule incorporated inside the nanocages can form the stable complex. Our calculation results reveal that the penetration of H-2 molecule into the C-60 nanocage might be easier than that of the C48N12 nanocage, with barrier energies of about 11.87 and 13.07 eV, respectively. Furthermore, our first-principles calculations demonstrated that the HOMO-LUMO gaps of the considered complexes increased in comparison to the original nanocages, except for the H-2@C33N9 complex, hence the reactivity of the respected complexes decreased with the environment.