Atomic modulation of Fe-Co pentlandite coupled with nitrogen-doped carbon sphere for boosting oxygen catalysis

Reversible oxygen reaction plays a crucial role in rechargeable battery systems, but it is limited by the slow reaction kinetics. Herein, the ionic modulation of cobalt pentlandite coupled with nitrogen-doped bowl-like hollow carbon sphere is well designed on octahedral and tetrahedral sites. The robust FexCo9–xS8-NHCS-V with iron replacing at the octahedron possesses prolonged metal sulfur bond and exhibits excellent bifunctional electrocatalytic performance towards oxygen reduction reaction (ORR, E1/2 = 0.80 V vs. RHE) and excellent oxygen evolution reaction (OER, Ej = 10 = 1.53 V vs. RHE) in 0.1 mol/L KOH. Accordingly, a rechargeable Zn-air battery of FexCo9–xS8-NHCS-V cathode endows high energy efficiency (102 mW cm−2), and a microbial fuel cell achieves a high-power density (791 ± 42 mW m−2), outperforming the benchmark Pt/C catalyst.