Comparison of PPy/sulfate-copper complexes synthesized by the pulse method and the traditional DC method

Polypyrrole/sulfate-copper (PPy/SO4-Cu) complexes were synthesized by different methods, including the one-step potential pulse method and the traditional direct current (DC) two-step method. The two methods were analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) to find out the influence of the different synthesis methods on the film composition and structure. Finally, the alkalescence stability of these films was studied by comparing the electroredox activity through cyclic voltammetry (CV) and electrochemical impedance (EIS) measurements. The results demonstrate that the PPy/SO4-Cu films synthesized by different methods show the same Cu combination model (i.e., Cu+ was combined with N on the PPy chains to form the PPy/SO4-Cu films). However, the film made by the one-step pulse method had smaller PPy particles and much higher Cu content. In addition, the PPy-Cu film synthesized by the one-step pulse method showed improved alkalescence stability, which can be attributed to the higher Cu content present uniformly in the film.