Confined Co9S8 into a defective carbon matrix as a bifunctional oxygen electrocatalyst for rechargeable zinc–air batteries†
Porous nanostructures with high specific surface area and small-sized nanoparticles always exhibit an extraordinary electrochemical catalysis. In this study, we report an efficient method to obtain size-controllable Co9S8 derived from metal organic frameworks (MOFs) as a bi-functional catalyst. The particle size of Co9S8 could be finely controlled by tuning the Zn/Co molar ratios in the precursors. The obtained material exhibited optimal performance towards oxygen reactions and zinc–air batteries. The prominent electrochemical properties are mainly ascribed to the synergistic effect of small-sized Co9S8 and the heteroatom-doped carbon matrix.