Co3O4 nanorods–graphene composites as catalysts for rechargeable zinc-air battery

Composite of Co3O4 nanorods with reduced graphene oxide (RG-Co3O4) for rechargeable zinc-air battery was prepared by a facile method. The Co3O4 nanorods with a length of 1–2 μm were homogeneously distributed on the surface of plicated graphene nanosheets. The samples were characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The RG-Co3O4 composite showed better electrode potential and higher electrical conductivity compared with pure Co3O4. The zinc-air battery can be reversibly charged and discharged for hundred cycles with a good cycle performance. The improved battery performance of RG-Co3O4 can be attributed to the synergistic coupling effect between the graphene sheets and Co3O4.