Nitrogen doped CuCo2O4 nanoparticles anchored on beaded-like carbon nanofibers as an efficient bifunctional oxygen catalyst toward zinc-air battery.

The elaborative design and construction of first-rank bifunctional oxygen electrocatalysts featuring low price, high activity and strong stability is critical for the large-scale applications of rechargeable Zn-air batteries. Here, a resultful strategy is proposed for fabricating nitrogen-doped 1D beaded-like structure carbon nanofibers uniformly decorated with nitrogen-doped CuCo2O4 nanoparticles (N-CuCo2O4@CNFs) toward boosting oxygen evolution reaction/oxygen reduction reaction (OER/ORR) catalysis. Taking advantage of the synergistic effect between interconnected 1D hierarchical porous carbon nanofiber structure and high catalytic activity of N-doped CuCo2O4 nanoparticles derived from bimetallic MOFs, the N-CuCo2O4@CNFs catalysts possess enhanced reaction kinetics and preferable charge transfer ability. Impressively, the obtained catalysts exhibit prominent electrocatalytic ability and superior stability for OER/ORR, even surpass the commercial RuO2 and Pt/C. More significantly, the Zn-air batteries employing the N-CuCo2O4@CNFs-800 as cathode display a higher power density of 175.6 mW cm-2, a lower charge-discharge voltage gap of 0.82 V at 10 mA cm-2, as well as a better cycling stability with respect to those of Pt/C + RuO2 mixture, demonstrating the great potential of N-CuCo2O4@CNF as a high-efficiency catalyst for clean energy devices.