Submicron Co 9 S 8 /CoS/Carbon Spheres Derived from Bacteria for the Electrocatalytic Oxygen Reduction Reaction

Abstract Synthesizing non‐noble metal electrocatalysts with both high activity and high stability for the oxygen reduction reaction (ORR) is of great significance in the fuel cell and metal‐air battery industries. Herein, a facile method is explored to fabricate submicron Co 9 S 8 /CoS/C spheres by using Streptococcus thermophiles as a template. The electrocatalytic activity for the ORR with an onset and half‐wave potential of 0.87 and 0.79 V, respectively, vs. RHE approaches that of commercial Pt/C catalyst. The durability and methanol tolerance are better than those of the commercial catalyst. The good performance could be attributed to the coupling effect between Co 9 S 8 /CoS and the bio‐carbon substrate, as well as the robust submicron sphere morphology. Benefiting from the structural diversity of bacteria, this method can be extended to the synthesis of sulfide catalysts with other elaborate architectures.