Hemijska industrija 2014 Volume 68, Issue 6, Pages: 709-719
https://doi.org/10.2298/HEMIND140305063P
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Capacitive properties of polypyrrole/activated carbon composite
Porjazoska-Kujundziski Aleksandra (International Balkan University, Faculty of engineering, Republic of Macedonia)
Chamovska Dragica (Faculty of Technology and Metallurgy, Sts. Cyril & Methodius University, Skopje, Republic of Macedonia)
Grchev Toma (Sts. Cyril & Methodius University, Faculty of Technology and Metallurgy, Skopje, Republic of Macedonia)
Electrochemical synthesis of polypyrrole (PPy) and polypyrrole / activated
carbon (PPy / AC) - composite films, with a thickness between 0.5 and 15 μm
were performed in a three electrode cell containing 0.1 mol dm-3 Py, 0.5 mol
dm-3 NaClO4 dissolved in ACN, and dispersed particles of AC (30 g dm-3).
Electrochemical characterization of PPy and PPy / AC composites was performed
using cyclic voltammetry (CV) and electrochemical impedance spectroscopy
(EIS) techniques. The linear dependences of the capacitance (qC), redox
capacitance (qred), and limiting capacitance (CL) of PPy and PPy / AC -
composite films on their thickness (L), obtained by electrochemical and
impedance analysis, indicate a nearly homogeneous distribution of the
incorporated AC particles in the composite films (correlation coefficient
between 0.991 and 0.998). The significant enhancement of qC, qred, and CL,
was observed for composite films (for ∼40 ± 5%) in respect to that of the
“pure” PPy. The decreased values of a volume resistivity in the reduced state
of the composite film, ρ = 1.3 ⋅ 106 Ω cm (for L = 7.5 μm), for two orders of
magnitude, compared to that of PPy - film with the same thickness, ρ ∼ 108 Ω
cm, was also noticed.
Keywords: conducting polymers, composites, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), electrical equivalent circuits (EECs)