Fig. 4: Theoretical analysis of the OER for the IrO2NR.

a Crystal structure of the IrO2NR with an exposed edge for the (001) plane during theoretical calculation. The reaction mechanisms of the OER over the (b) Rutile IrO2 (110) and (c) IrO2NR (100) samples. d Corresponding 4e- thermodynamic diagram of free energy evolution. e Comparison of the d-orbital distribution of the Ir atoms in the Rutile IrO2 and IrO2NR samples. Blue, yellow, and pink balls represent Ir, O and H elements, respectively.