Electrochemical impedance of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber

In this paper, copolymer of 9-tosyl-9H-carbazole (TCz) and pyrrole (Py) comonomers were electrochemically deposited onto carbon fiber micro electrode (CFME) as an active electrode material. An electrochemical impedance study on the prepared electrodes is reported. Poly(TCz-co-Py)/CFME is characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy–energy dispersive X-ray analysis (SEM–EDX), and electrochemical impedance spectroscopy (EIS). Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode-magnitude and Bode-phase plots. An examination is made of which equivalent circuits of R(C(R(Q(RW)))) and R(C(R(Q(RW))))(CR) used for modeling the system. The effect of monomer ratio (mole fraction, XTCz = nTCz/nTCz + nPy) on the formation of copolymer is reported in 0.1 M sodium perchlorate (NaClO4)/acetonitrile (ACN) solution. The inclusion of TCz in the copolymer structure was also confirmed by FTIR-ATR, SEM, and CV measurements. The highest low frequency capacitance (CLF = 22.7 for R(C(R(Q(RW)))) and CLF = 22.6 mF cm−2 for R(C(R(Q(RW))))(CR)) were obtained for XTCz = 0.91.