Synergistic Effects of Phase Transition and Electron-Spin Regulation on the Electrocatalysis Performance of Ternary Nitride

Transition metal nitrides (TMNs) have great potential use in energy storage and conversion owing to tunable electronic and bonding characteristics. Novel iron rich nitrides nanoparticles anchored on the N-doped porous carbon, named as (CoxFe1–x)3N@NPC (0 ≤ x < 0.5) are designed here. The synergistic effects of phase transition and electron-spin regulation on oxygen electrocatalysis are testified. A core–shell structure of (CoxFe1–x)3N with high dispersibility is induced by an intermediate phase transition process, which significantly suppresses coarsening of the metallic nitrides. The Co incorporation regulates d-band electrons spin polarization. The t2g5eg1 of FeII with the ideal eg electron filling boosts intrinsic activity. (Co0.17Fe0.83)3N@NPC with optimal cobalt content holds electronic configuration with moderate eg electron filling (t2g5eg1), which balances the adsorption of *O2 and the hydrogenation of *OH, improving bifunctional catalytic performances. Both liquid and solid-state zinc–air batteries assembled based (Co0.17Fe0.83)3N@NPC cathodes substantially deliver higher peak power density and remarkable energy density.