Figure 4From: Vertically aligned ZnO nanorod core-polypyrrole conducting polymer sheath and nanotube arrays for electrochemical supercapacitor energy storageSchematic representation of the evolution of the PPy sheath and nanotube structure. Schematic representation of ZnO nanorod core coated by PPy sheath (A-C) and formation of PPy nanotube array after 2- and 4-h etch (D-E). Top view (F).Back to article page