Poly(3,5-dithiophene-2-yldithieno[3,2-b;2′,3′-d] thiophene-co-ethylenedioxythiophene)glassy carbon electrode formation and electrochemical impedance spectroscopic study

3,5-Dithiophene-2-yldithieno[3,2-b;2′,3′-d]thiophene (Thy ₂DTT) and ethylenedioxythiophene (EDOT) were electro-copolymerized on glassy carbon electrode (GCE) in 0.1 M sodium perchlorate (NaClO _4+δ)acetonitrile (ACN)dichloromethane (CH ₂Cl ₂) (8:2) solution. Poly(Thy ₂DTT-co-EDOT)GCE thin film was characterized by various techniques, such as Cyclic Voltammetry (CV), Fourier Transform Infrared Spectroscopy - Attenuated Transmittance Reflectance (FTIR-ATR), Scanning Electron Microscopy - Energy Dispersive X-ray analysis (SEM-EDX) and Electrochemical Impedance Spectroscopy (EIS). The effects of monomer mole fractions (mole fraction, X _Thy2DTT=n _Thy2DTTn _EDOT+n _Thy2DTT) (0.5, 0.66 and 0.83) during the preparation of modified electrodes were examined by EIS. Capacitive behaviors of the modified GCE were defined via Nyquist, Bode-magnitude, Bode-phase and Capacitance plots. The circuit model was used to fit the theoretical and experimental data through Kramers-Kronig Transform test. The lowest frequency capacitance (C _LF) value was obtained as C _LF = 0.89 mFcm ^-2 for poly(Thy ₂DTT). However, the highest C _LF was obtained for the copolymer as C _LF = 1.11 mFcm ^-2 for X _Thy2DTT = 0.66 and 0.83. Potential application of the copolymer could be energy-storage devices.