Poly(2,6‐di(thiophene‐2‐yl)‐3,5bis(4‐(thiophene‐2‐yl)phenyl)dithieno [3,2‐b;2',3'‐d]thiophene)/carbon nanotube composite for capacitor applications

Abstract

AbstractA novel monomer, 2,6‐di(thiophene‐2‐yl)‐3,5bis(4‐(thiophene‐2‐yl)phenyl)dithieno[3,2‐b;2',3'‐d]thiophene (Th4DTT) has been synthesized and used as an electro‐active material. It has been electropolymerized onto glassy carbon (GC) electrode in sodium dodecyl sulfate (SDS) solution (0.1 M) together with multi‐walled carbon nanotubes (MWCNT). A good capacitive characteristics for P(Th4DTT)/MWCNT composite has been obtained by electrochemical impedance spectroscopy (EIS), which is, to our best knowledge, the first report on capacitor behavior of a dithienothiophene. A synergistic effect has been resolved by Nyquist, Bode‐magnitude—phase and admittance plots. Specific capacitance of the conducting polymer/MWCNT, calculated from cyclic voltammogram (CV) together with area and charge formulas, has been found to be 20.17 F g−1. Long‐term stability of the capacitor has also been tested by CV, and the results indicated that, after 500 cycles, the specific capacitance is 87.37% of the initial capacitance. An equivalent circuit model of Rs(C1(R1(Q(R2W))))(C2R3) has been obtained to fit the experimental and theoretical data. The double layer capacitance (Cdl) value of P(Th4DTT)/MWCNT (4.43 mF cm−2) has been found to be 25 times higher than P(Th4DTT) (Cdl= 0.18 mF cm−2). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40061.