Conjugated polymerized bimetallic phthalocyanine based electrocatalyst with Fe−N4/Co−N4 dual-sites synergistic effect for zinc-air battery

The bifunctional oxygen catalyst is essential for zinc-air batteries (ZABs). Here, an efficient bifunctional oxygen catalyst, PPcFeCo/3D-G, is obtained through π-π interaction between the conjugated polymerized iron-cobalt phthalocyanine (PPcFeCo) with excellent thermal stability and three-dimensional graphene (3D-G). The bimetallic synergistic effect of PPcFeCo, verified by DFT (Density functional theory) calculation, and π-π interactions enhances the catalytic activity and durability of the PPcFeCo/3D-G. Regarding electrochemical performance, the PPcFeCo/3D-G with a high electron transfer number (3.98, @0.768 V vs. RHE) has excellent half-wave potential (E1/2 = 0.890 V vs. RHE) and exhibits outstanding reversibility (ΔE = 0.700 V, ΔE = Ej=10 − E1/2). The liquid ZAB (LZAB) employed PPcFeCo/3D-G displays a high power density (222 mW cm−2), a specific capacity (792 mA h g−1), and excellent durability (120 h). This work has guiding significance for the preparation of high-efficiency bifunctional catalysts.