Synergistic effect of Cu and Fe on chitosan-glutamic acid hydrogel for green synthesis of N doped carbon with CuFe dual atomic clusters for Zn-air batteries

Carbon based dual-metal sites materials have garnered considerable attention owing to their atomically dispersed active sites and synergistic effects. However, precise control over the coordination environment and prevention of metal aggregation remain challenging. Herein, we demonstrate a green synthesis of Cu-Fe dual atomic clusters on N-doped porous carbon (CuFe AC@NC) via a chitosan-glutamic acid hydrogel platform. The hydrogel’s amino/hydroxyl/carboxyl groups ensure uniform bimetallic dispersion and inhibit pyrolysis-induced aggregation. Combined experimental and theoretical analyses reveal the distinct roles of Cu and Fe: Fe induces catalytic graphitization for hierarchical pores and enhanced ORR activity, while Cu modulates electronic states and prevents Fe aggregation. The optimized CuFe AC@NC exhibits exceptional ORR activity, and enables Zn-air batteries with a high open-circuit voltage (1.470 V), remarkable specific capacity (806.2 mAh g −1 ), and stable cycling performance. This work provides a green methodology for designing dual-metal-site catalysts and elucidates structure–property relationships, advancing the development of cost-effective energy storage systems.