Theoretical studies of LOM and AEM of Fe-LNO. (a) The ABO3 structures with chemical reaction surface [BO5]. (b, c) The proposed OER mechanisms of LNO, including AEM and LOM. (d) Schematic rigid band diagrams of LNO. The position of the O2/H2O redox couple at pH 14 is 1.23 V versus RHE. (e, f) Free energies of OER steps via AEM and LOM mechanisms on LNO. (g, h) The constructed model of Fe-LNO heterostructure. (i) The hydroxl adsorption energy of LNO and Fe-LNO. (j) LOM mechanism optimized by FeOOH. (k) pDOS of O(2p) and Ni(3d) orbitals in the surface NiO5 and bulk NiO5.