3D porous gear-like copper oxide and their high electrochemical performance as supercapacitors

Abstract

A facile and mild approach was used for the controlled synthesis of 3D porous gear-like CuO on a Cu substrate (PGC) based on annealing gear-like Cu(OH)2 (GC) at 200 °C in air. There are 3–10 edges that build up a gear-like structure and a huge number of holes formed on each edge. As an integrated nanostructure, the binder-free PGC can be used as a supercapacitors electrode (SC) directly. Due to its 3D porous structure and the highly conductive Cu substrate as a current collector, the integrated electrode exhibited excellent electrochemical properties. These were demonstrated by excellent specific capacitance as high as 348 F g−1 at a discharge current density of 1 A g−1, which corresponds to the energy density of 43.5 Wh kg−1. The electrochemical tests also showed that the as-synthesized PGC exhibited excellent cycling stability.