High-performance ordered porous Polypyrrole/ZnO films with improved specific capacitance for supercapacitors

Ordered porous polypyrrole/ZnO (PPy/ZnO) nanocomposites were synthesized on a fluorine tin oxide (FTO) substrate using an independent ZnO nanorod array template-assisted electrodeposition and template removal process with a pore size between 100 nm and 200 nm. The ordered porous structure of PPy/ZnO was verified by scanning electronmicroscopy (SEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FTIR). The specific capacitance of porous PPy/ZnO nanocomposites can be as high as 161.02 F g(-1), which is far higher than pure PPy (100.17 F g(-1)) at 1 M KCl aqueous solution with a current density of 0.5 A g(-1). The improvement of specific capacitance performance is not only ascribe to the exposure of more active sites to obtain larger specific surface area, but also because of the synergistic effect between conductive PPy and ZnO, which shorten the electron transport channel, enhance the transmission efficiency of electrons in the entire electrode, and consequently result in a faster electron transfer. The specific capacitance of the porous PPy/ZnO nanocomposites retains 70.71% after 5000 cycles of charge/discharge, exhibiting good electrochemical cycle stability, which provides a potential as high-performing electrode material in supercapacitors.