Synergistic interaction between embedded Co3O4 nanowires and graphene papers for high performance capacitor electrodes

Abstract

Graphene/Co3O4 nanowire composite films were successfully synthesized using a simple, three-step treatment, and the effect of the Co3O4 nanowire content on the electrochemical properties of the composite films was studied. The one-dimensional Co3O4 nanowires were homogeneously embedded and dispersed between prepared graphene papers, forming a layered graphene/Co3O4 nanowire hybrid structure. These composite films exhibited better electrochemical properties than previously reported ones, such as graphene/CNT, where carbon spheres existed in the graphene composites, which were fabricated using the same method but without the Co3O4 nanowires. The addition of a small amount of Co3O4 - typically 8-:-1 by weight (reduced graphene oxide (RGO)-:-Co3O4) - to form thick RGO/Co3O4 sandwiches in the form of papers resulted in an excellent specific charge capacity of 278.936 C g-1 at a scan rate of 5 mV s-1. These results indicate the potential of the composite for the development of highly capacitive energy storage devices for practical applications.