Abstract: The electrooxidative behaviors of sulfonated 4,4′-biphenyl diphenol were investated on the stainless steel electrode by electrochemical methods. The alternative current(AC) impedance responses of the electrolyte system between the electrodes before and after electrooxidation were also in situ monitored. The results show that the electrooxidation of sulfonated 4,4′-biphenyl diphenol is irreversible similar to those of other phenolic compounds, and the onset potential and peak potential are 0.95 V and 1.2 V, respectively. After electrooxidation, the corresponding AC impedance increases only by 0.27 Ω·cm2， possibly due to the formation of polymer film. This increase is slight, which is attributed to the double promoting effects of biphenol and sulfonated acid group.

Key words: Sulfonated biphenyl diphenol, cyclic voltammetry, Chronamperometry, electrochemical impedance spectroscopy, Electrooxidization