Fig. 4: OER activity comparison of the doped LaNiO3 (001)cubic surfaces.

a This plot shows the variation of the OER current density of the films with 5% doping as a function of applied potential vs. RHE. b The bar graph compares the difference between the OER current densities of the doped (001) surfaces measured at 1.63 V vs. RHE. For an easier comparison, a black vertical line is added on the graph, showing the OER current density of the pristine (001) surface. As denoted, Fe, Co, Cr, and Al have a notably beneficial effect on the OER activity, while Sc, Mn, and In make little contribution.