Fig. 2: Structural evolution of the IrO₂NR.

a, b From the raw materials of IrCl₃ and KOH to K_0.25IrO₂. c, d From K_0.25IrO₂ to the IrO₂NR. Purple, blue, yellow, green and pink balls represent K, Ir, O, Cl and H elements, respectively.