Active‐Site Interactions in a Synergistic Porous Structured Fe Nanoparticle–Carbon Electrocatalyst for Enhanced Redox Reactions in Alkaline Zn–Air Batteries

In practical applications, zinc–air batteries (ZABs) require high‐performance, durable, and cost‐effective electrocatalysts for the critical oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here, we describe a reflux synthesis method of constructing a porous catalyst by introducing turmeric yellow into extremely porous bio‐carbon (PC) materials that contain iron nanoparticles (Fe NPs); these catalysts are known as Fe NPs@PC. These catalysts have become a significant substitute for high‐performance cathodes in ZABs because their electrochemical properties can improve ORR performance. In addition to enhancing conductivity, the OER/ORR bifunctional active sites must be balanced by optimizing the FeC and FeFe interactions within the active site. X‐ray absorption analysis and density functional theory confirmed that strong iron‐carbon interactions promote OER ( η 10 = 320 mV) and ORR ( E 1/2 = 0.786 V) activity and exhibit a smaller potential gap of 0.764 V of Fe NPs@PC‐700 catalyst. The impact of this redox activity enhances the high‐power density (219 mW cm −2 ) and long‐term charge–discharge cycle stability (85 h@3 mA cm −2 ) of ZABs. This work charts a viable route for the assembly of practical ZABs by regulating bifunctional electrocatalysts via appropriate modification of active sites.