Facile Synthesis of Co3O4/Nitrogen-Doped Graphene Composite and their Electrochemical Performances

Co3O4/Nitrogen-doped graphene (Co3O4/NG) composites were synthesized by a simple hydrothermal method. The Co3O4/NG composites show a better electrochemical performance than the Co3O4/graphene (Co3O4/G) composite. The specific capacitance of Co3O4/NG electrode is 428 F/g (290 F/g for Co3O4/G electrode) at a current density of 1 A/g. As the current density was increased from 1 to 8 A/g, the capacitance of Co3O4/NG still retained 57%, significantly larger than that of Co3O4/G (40%). Moreover, over 94% of the original capacitance was maintained after 500 cycles (72% for Co3O4/G electrode), indicating a good cycle stability of Co3O4/NG electrode materials.