Copolymer formation of 9-(2-(benzyloxy)ethyl)-9H-carbazole and 1-tosyl-1H-pyrrole coated on glassy carbon electrode and electrochemical impedance spectroscopy

Abstract

In this work, 9-(2-(benzyloxy)ethyl)-9H-carbazole (BzOCz) and 1-tosyl-1H-pyrrole (TsP) monomers were chemically synthesized and characterized by Fourier transform infrared reflectance (FTIR) and proton nuclear magnetic resonance (H-1-NMR) spectroscopy. BzOCz and TsP were electrocoated on glassy carbon electrode (GCE) in various molar fractions (X (TsP) = 0.5, 0.83, 0.91, and 0.98) in 0.1 M sodium perchlorate/acetonitrile. The detailed characterization of poly(BzOCz-co-TsP) was studied by cyclic voltammetry, FTIR-attenuated total reflection spectroscopy and electrochemical impedance spectroscopy (EIS). The effects of different molar fractions during the preparation of modified electrodes were studied by EIS technique. The AC impedance technique was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode magnitude, and Bode phase plots. The highest low frequency capacitance value was obtained as C (LF) = 23.94 mu F cm(-2) for X (TsP) = 0.98. Therefore, synthesized copolymer has more capacitive behavior than its homopolymers, such as C (LF) = 7.5 mu F cm(-2) for poly(BzOCz) and C (LF) = 9.44 mu F cm(-2) for poly(TsP). In order to interpret the AC impedance spectra, R(Q(RW)) electrical equivalent circuit was employed with linear Kramers-Kronig test. A mechanism for electropolymerization has been proposed for copolymer formation.