CuxO-Modified Nanoporous Cu Foil as a Self-Supporting Electrode for Supercapacitor and Oxygen Evolution Reaction

Abstract

Designing and modifying nanoporous metal foils to make them suitable for supercapacitor and catalysis is significant but challenging. In this work, CuxO nanoflakes have been successfully in situ grown on nanoporous Cu foil via a facile electrooxidation method. A Ga-assisted surface Ga-Cu alloying–dealloying is adopted to realize the formation of a nanoporous Cu layer on the flexible Cu foil. The following electrooxidation, at a constant potential, modifies the nanoporous Cu layer with CuxO nanoflakes. The optimum CuxO/Cu electrode (O-Cu-2h) delivers the maximum areal capacitance of 0.745 F cm−2 (410.27 F g−1) at 0.2 mA cm−2 and maintains 94.71% of the capacitance after 12,000 cycles. The supercapacitor consisted of the O-Cu-2h as the positive electrode and activated carbon as the negative electrode has an energy density of 24.20 Wh kg−1 and power density of 0.65 kW kg−1. The potential of using the electrode as oxygen evolution reaction catalysts is also investigated. The overpotential of O-Cu-2h at 10 mA cm−2 is 394 mV; however, the long-term stability still needs further improvement.

Recent innovations in the technology and applications of low-dimensional CuO nanostructures for sensing, energy and catalysis

“…The supercapacitor built using Cu x O/Cu as the positive electrode and activated carbon as the negative electrode demonstrated energy and power densities of 24.2 W h kg −1 and 0.65 kW kg −1 , respectively. 185…”

“…The supercapacitor built using Cu x O/Cu as the positive electrode and activated carbon as the negative electrode demonstrated energy and power densities of 24.2 W h kg À1 and 0.65 kW kg À1 , respectively. 185 Another technology for CuO-based supercapacitors has been reported recently by Lim et al, in which a porous Cu mesh was implemented as the current collector, while a porous surface was made via thermal annealing of the Cu mesh in an ammonia gas environment. 186 Activated graphene, with a hierarchical porous distribution and a high specific surface area, and graphene oxide were deposited onto the porous Cu substrate via electrophoretic deposition.…”

Surface-Reconstructed Copper Foil Free-Standing Electrode with Nanoflower Cu/Ce2O3 by In Situ Electrodeposition Reduction for Electrocatalytic Nitrate Reduction to Ammonia

“…Free-standing electrodes combining the current collectors and catalysts without binders can enhance charge transfer and interfacial stability. , Copper foil has been utilized in research on lithium-ion batteries, supercapacitors, and electrocatalysis due to its good conductivity and low cost. However, its low activity, susceptibility to oxidation, and corrosion have limited its broader investigation. − …”