Facile Synthesis of Amorphous CuO Nanosheets on Nickel Foam by Utilizing ZnO Nanowires for High-Performance Supercapacitors

In this work, porous CuO nanosheets were synthesized on nickel foam using ZnO nanowires as adhesion layers, for applications in electrodes of electrochemical energy storage devices. The preparation method is simple and low-cost. The amorphous phase could provide various advantages over crystalline CuO, such as a better rate capability, low synthesis temperature, and simpler synthesis process. Despite these potentials, reports on amorphous CuO structures are rare. Electrochemical characterizations show that the porous CuO nanosheets exhibit a very high specific capacitance (621 F g−1), stable galvanostatic charge/discharge behavior, and low equivalent series resistance (0.97 Ω). The specific capacitance value is, to the best of our knowledge, one of the largest among those of previously reported CuO structures. This study demonstrates that amorphous CuO nanosheets can be used as electrodes of a next-generation architecture for high-performance electrochemical energy storage devices.