fig4
Figure 4. Cyclic voltammograms of (a) CuO nanowires, (b) CuO nanosheets and (c) CuO nanoflowers recorded in a 6.0 mol L-1 KOH solution at a scan rate of 20 mV s-1. The inset shows the cyclic voltammograms of the Cu foam substrate and the CuO nanowires on the Cu foam electrode with the same geometrical area of 1 cm2[91]. Reproduced from Ref.[91] with permission from Elsevier.
