Improved oxygen reduction activity and stability on N, S-enriched hierarchical carbon architectures with decorating core-shell iron group metal sulphides nanoparticles for Al-air batteries

Abstract

To rational design non-noble catalysts with oxygen reduction reaction (ORR) activity and durability superior to that of Pt/C, we report the fabrication of iron group metal sulphides immobilized inside hierarchically porous N,S-enriched carbon architecture using a facile double-phase encapsulation approach followed by a pyrolysis process. The as-prepared hybrid architectures exhibit significantly enhanced electrocatalytic activity towards the ORR, including a positive onset potential, low Tafel slope, and high electron transfer number. In particular, the ORR activity of FeS@G/NSC is even superior to that of the Pt/C benchmark, which possesses an outstanding onset potential (0.99 V vs RHE) and a high discharge voltage plateau (∼1.47 V at discharge current density of 50 mA cm−2 in the Al-air battery test) with excellent stability. These hybrid carbon architectures provide a new direction for carbon-based ORR electrocatalysts performance optimization for next-generation air batteries.