The 3D Co3O4/graphene/nickel foam electrode with enhanced electrochemical performance for supercapacitors

• Graphene and Co3O4 ultrathin layers have been decorated on Ni foam.
• The electrode exhibits a high specific capacitance of 1126 F g−1 at 7.5 A g−1.
• The electrode presents large electroactive surface area and excellent structural stability.

Nickel foam was decorated with graphene and cobalt oxide (Co3O4) sheets by chemical vapor deposition and electrochemical deposition, respectively. After coated by a thin graphene layer, the nickel foam was decorated with Co3O4 nanoparticles, ranging in size from 3 to 5 nm. The resulted electrode allowed the rapid transportation of electrons and ions with a large electroactive surface area, and showed excellent structural stability. The specific capacitance of the electrode was as high as 1126 F g−1 at a high current density of 7.5 A g−1 in KOH 3 M electrolyte, highlighting its promising applications as a high performance electrode for supercapacitors.