First-principle calculations study of pristine, S-, O-, and P-doped g-C3N4 as ORR catalysts for Li-O2 batteries

In this work, we investigated the ORR process on the surface of graphitic carbon nitride (g-C3N4), S-, O-, and P-doped g-C3N4 by the DFT method. According to the results, the reaction begins with Li adsorption and the first adsorbed Li atom is probably trapped on the considered substrates so the ORR process was also investigated on the surface with one trapped Li atom. The overpotential of the discharge process was obtained as 0.41 V for g-C3N4.S and 0.84 V for g-C3N4.S/Li which indicates that g-C3N4.S could be a promising candidate for application in Li-O2 battery.