Electrocoated Films of Poly(N-Methylpyrrole-co-2,2′-Bithitiophene-co-3-(Octylthiophene)), Characterizations, and Capacitor Study

Abstract

N-Methylpyrrole (N-MPy), 2,2′-bithiophene (BTh), and 3-(Octylthiophene) (OTh) were electrocopolymerized in 0.2 M NaClO4/CH3CN on glassy carbon electrode (GCE). The resulting terpolymers of N-MPy, BTh and OTh in different initial monomer feed ratios such as [N-MPy]0/[BTh]0/[OTh]0 = 1/1/1 and 1/2/5 were characterized by cyclic voltammetry (CV), Fourier-transform infrared attenuated total reflectance spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and electrochemical impedance spectroscopy (EIS). The capacitive behaviors of the modified electrodes were defined via Nyquist, Bode-magnitude, Bode-phase, and Admittance plots. The equivalent circuit model of Rs(C dl1 (R 1 (QR 2 )))(C dl2 R 3 ) was performed to fit the theoretical and experimental data. The low-frequency capacitance (CLF) were obtained from initial monomer concentrations of 50 mM as CLF = ∼2.34 × 10−4 mFcm−2 for P(N-MPy), CLF = 5.06 × 10−4 mF cm−2 for P(BTh), CLF = 5.07 m F cm−2 for P(OTh), and CLF = ∼3.78 m Fcm−2 for terpolymer for [N-MPy]0/[BTh]0/[OTh]0 = 1/1/1. The terpolymer may be used as energy storage devices.