One-step electrochemical synthesis of three-dimensional graphene foam loaded nickel-cobalt hydroxides nanoflakes and its electrochemical properties

Abstract In this work, we present a new type of three-dimensional (3D) nanohybrid electrode based on microscopic graphene foam loaded nickel − cobalt hydroxides nanoflakes (Ni x Co 2x (OH) 6x /graphene foam) synthesized by one-step electrochemical method. This method allows for better structural integration of different electrode component and improves the electrochemical properties in terms of capacitive performance and electrocatalytic activity. When used as binder-free electrode for supercapacitor, the 3D Ni x Co 2x (OH) 6x /graphene foam exhibits a high specific capacitance of 703.6 mF cm −2 at a current density of 10 mA cm −2 and a good rate capability of 83.8% at 100 mA cm −2 , and the specific capacitance retention remains 97.5% after 1000 cycles. Furthermore, for electrochemical biosensor application, the Ni x Co 2x (OH) 6x /graphene nanohybrid electrode exhibits high selectivity, reproducibility and stability towards the nonenzymatic detection of hydrogen peroxide. These enable it as a multifunctional electrode material for wide spectrum of electrochemical application.