N, S dual-doped carbon aerogels-supported Co9S8 nanoparticles as efficient oxygen reduction reaction electrocatalyst for zinc-air battery

The innovative design of highly active and noble-metal-free electrocatalysts for the oxygen reduction reaction (ORR) is urgently required for the widespread application of Zinc-air batteries (ZABs). This study presents a porous composite, Co 9 S 8 @NSC, which integrates N and S co-doped carbon aerogels with Co 9 S 8 nanoparticles to create ideal ORR electrocatalysts. The porous carbon aerogels posesess a high specific surface area, which offers abundant catalytic sites and efficient channels for the reactants and electrolytes, while maintaining a uniform distribution of nanoparticles during long-term operation. The collaboration of ORR-active Co 9 S 8 nanoparticles and N and S co-doped carbon aerogels significantly improves ORR performance. Co 9 S 8 @NSC demonstrates a competitive ORR activity, including a high half-wave potential (E 1/2 , 0.85 V), fast electron transfer kinetics (Tafel slop, 53.3 mV dec −1 ), and prominent long-term stability. When utilized as an air cathode catalyst in primary Zn-air batteries, the Co 9 S 8 @NSC electrode displays a power density of 150.9 mW cm −2 and a specific capacity of 735 mAh g zn −1 . Overall, this work presents a promising electrocatalyst design for ORR, which could greatly benefit the development of ZABs.