Assessing pseudocapacitive and OER-HER electrocatalytic potential of bimetallic Copper-Nickel/Graphene oxide nanocomposite

Abstract

Copper-nickel oxide/GO (CNO/GO) nanocomposite was synthesized via a low-temperature thermal reduction technique with crystallographic phase matching with an off-stoichiometric type Cu_0.05Ni_0.95O/GO structure. Three-electrode-based electrochemical experiments suggest that the prepared CNO/GO nanocomposite can store energy via the pseudocapacitive mechanism. The charge storage efficacy is also reflected in the high-power density value (∼267 W/kg) achieved at a current density of 1 A/g compared to earlier reported nickel oxide-based composites. The practical performance of the CNO/GO nanocomposite can be corroborated by the fact that in a symmetric coin cell device, it results in a specific capacity of ∼37F/g @ 1A/g and retains its ∼84 % specific capacity after 8000 cycles. The flexibility of using CNO/GO nanocomposite as an exceptional electrocatalytic material can be recognized from the smaller overpotential (η) values, e.g., 340 mV and 359 mV for OER and HER, respectively, in conjunction with chronoamperometric stability retained over 24 h. All these multiple electrochemical attributes establish the potential of using CNO/GO nanocomposite in energy storage and conversion.