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The structure and properties of PEDOT synthesized by template-free solution method.

Zhao Q, Jamal R, Zhang L, Wang M, Abdiryim T - Nanoscale Res Lett (2014)

Bottom Line: In this study, a simple one-step template-free solution method was developed for the preparation of poly(3,4-ethylenedioxythiophene) (PEDOTs) with different morphologies by adjusting various ratios of oxidant (FeCl3·6H2O) to monomer (3,4-ethylenedioxythiophene (EDOT)).The morphological analysis showed that PEDOT prepared from an oxidant/monomer ratio of 3:1 displayed a special coral-like morphology, and the branches of 'coral' would adjoin or grow together with increasing content of oxidant in the reaction medium; consequently, the morphology of PEDOT changed from coral to sheets (at an oxidant/monomer ratio of 9:1).The electrochemical analysis proved that the PEDOT prepared from an oxidant/monomer ratio of 3:1 had the lowest resistance and the highest specific capacitances (174 F/g) at a current density of 1 A/g with a capacity retention rate of 74% over 1,500 cycles, which indicated that the PEDOT with a coral-like morphology could be applied as a promising electrode material for supercapacitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Petroleum and Gas Fine Chemicals, Educational Ministry of China, School of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, People's Republic of China ; Key Laboratory of Functional Polymers, Xinjiang University, Urumqi 830046, People's Republic of China.

ABSTRACT
In this study, a simple one-step template-free solution method was developed for the preparation of poly(3,4-ethylenedioxythiophene) (PEDOTs) with different morphologies by adjusting various ratios of oxidant (FeCl3·6H2O) to monomer (3,4-ethylenedioxythiophene (EDOT)). The results from structural analysis showed that the structure of PEDOT was strongly affected by the oxidant/monomer ratio, and the polymerization degree, conjugation length, doping level, and crystallinity of PEDOT decreased with increasing of the oxidant/monomer ratio. The morphological analysis showed that PEDOT prepared from an oxidant/monomer ratio of 3:1 displayed a special coral-like morphology, and the branches of 'coral' would adjoin or grow together with increasing content of oxidant in the reaction medium; consequently, the morphology of PEDOT changed from coral to sheets (at an oxidant/monomer ratio of 9:1). The electrochemical analysis proved that the PEDOT prepared from an oxidant/monomer ratio of 3:1 had the lowest resistance and the highest specific capacitances (174 F/g) at a current density of 1 A/g with a capacity retention rate of 74% over 1,500 cycles, which indicated that the PEDOT with a coral-like morphology could be applied as a promising electrode material for supercapacitors.

No MeSH data available.


Equivalent circuit diagram to fit the observed impedance spectra in Figure7.
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Figure 8: Equivalent circuit diagram to fit the observed impedance spectra in Figure7.

Mentions: The equivalent circuit diagram used to fit the impedance spectrum is shown in Figure 8. All the impedance curves obtained are basically fitted with this unique equivalent circuit. It is composed of two frequency parts in Figure 7. A resistance of Rs (solution resistance) is in series with a parallel element circuit constant phase element (CPE) and a resistor Rct (Faradic charge transfer resistance), which can be attributed to the sum of electrolytic and the electrode material for the high-frequency semi-cycle observed in Figure 7. The second part element circuit of a resistor Rp (capacitor resistance) and the Ws (ionic diffusion Warburg impedance) can be attributed to the low-frequency domain.As it is well known, the long-term stability of conducting polymers is an important factor to consider for their applications in supercapacitors. The cycling performance of PEDOT with different structures is evaluated by repeating the galvanostatic charge/discharge test at the 1 A/g for 1,500 cycles in Figure 9. Among samples, PEDOT (3:1) displayed excellent capacity retention with only 26% decrease over 1,500 cycles. In addition, at the first 10 cycles, the SC of PEDOT (3:1) decreases sharply from 184 to 154 F/g, and it decreases to 74% after 180 cycles. However, PEDOT (6:1) and PEDOT (9:1) exhibit decay rapidly from 149 to 59 F/g and 135 to 40 F/g, respectively. Besides, PEDOT (3:1) reaches a stability state after 200 cycles, but the specific capacitance of PEDOT (6:1) and PEDOT (9:1) reaches the stability state after 460 and 1,040 cycles, respectively.


The structure and properties of PEDOT synthesized by template-free solution method.

Zhao Q, Jamal R, Zhang L, Wang M, Abdiryim T - Nanoscale Res Lett (2014)

Equivalent circuit diagram to fit the observed impedance spectra in Figure7.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196207&req=5

Figure 8: Equivalent circuit diagram to fit the observed impedance spectra in Figure7.
Mentions: The equivalent circuit diagram used to fit the impedance spectrum is shown in Figure 8. All the impedance curves obtained are basically fitted with this unique equivalent circuit. It is composed of two frequency parts in Figure 7. A resistance of Rs (solution resistance) is in series with a parallel element circuit constant phase element (CPE) and a resistor Rct (Faradic charge transfer resistance), which can be attributed to the sum of electrolytic and the electrode material for the high-frequency semi-cycle observed in Figure 7. The second part element circuit of a resistor Rp (capacitor resistance) and the Ws (ionic diffusion Warburg impedance) can be attributed to the low-frequency domain.As it is well known, the long-term stability of conducting polymers is an important factor to consider for their applications in supercapacitors. The cycling performance of PEDOT with different structures is evaluated by repeating the galvanostatic charge/discharge test at the 1 A/g for 1,500 cycles in Figure 9. Among samples, PEDOT (3:1) displayed excellent capacity retention with only 26% decrease over 1,500 cycles. In addition, at the first 10 cycles, the SC of PEDOT (3:1) decreases sharply from 184 to 154 F/g, and it decreases to 74% after 180 cycles. However, PEDOT (6:1) and PEDOT (9:1) exhibit decay rapidly from 149 to 59 F/g and 135 to 40 F/g, respectively. Besides, PEDOT (3:1) reaches a stability state after 200 cycles, but the specific capacitance of PEDOT (6:1) and PEDOT (9:1) reaches the stability state after 460 and 1,040 cycles, respectively.

Bottom Line: In this study, a simple one-step template-free solution method was developed for the preparation of poly(3,4-ethylenedioxythiophene) (PEDOTs) with different morphologies by adjusting various ratios of oxidant (FeCl3·6H2O) to monomer (3,4-ethylenedioxythiophene (EDOT)).The morphological analysis showed that PEDOT prepared from an oxidant/monomer ratio of 3:1 displayed a special coral-like morphology, and the branches of 'coral' would adjoin or grow together with increasing content of oxidant in the reaction medium; consequently, the morphology of PEDOT changed from coral to sheets (at an oxidant/monomer ratio of 9:1).The electrochemical analysis proved that the PEDOT prepared from an oxidant/monomer ratio of 3:1 had the lowest resistance and the highest specific capacitances (174 F/g) at a current density of 1 A/g with a capacity retention rate of 74% over 1,500 cycles, which indicated that the PEDOT with a coral-like morphology could be applied as a promising electrode material for supercapacitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Petroleum and Gas Fine Chemicals, Educational Ministry of China, School of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, People's Republic of China ; Key Laboratory of Functional Polymers, Xinjiang University, Urumqi 830046, People's Republic of China.

ABSTRACT
In this study, a simple one-step template-free solution method was developed for the preparation of poly(3,4-ethylenedioxythiophene) (PEDOTs) with different morphologies by adjusting various ratios of oxidant (FeCl3·6H2O) to monomer (3,4-ethylenedioxythiophene (EDOT)). The results from structural analysis showed that the structure of PEDOT was strongly affected by the oxidant/monomer ratio, and the polymerization degree, conjugation length, doping level, and crystallinity of PEDOT decreased with increasing of the oxidant/monomer ratio. The morphological analysis showed that PEDOT prepared from an oxidant/monomer ratio of 3:1 displayed a special coral-like morphology, and the branches of 'coral' would adjoin or grow together with increasing content of oxidant in the reaction medium; consequently, the morphology of PEDOT changed from coral to sheets (at an oxidant/monomer ratio of 9:1). The electrochemical analysis proved that the PEDOT prepared from an oxidant/monomer ratio of 3:1 had the lowest resistance and the highest specific capacitances (174 F/g) at a current density of 1 A/g with a capacity retention rate of 74% over 1,500 cycles, which indicated that the PEDOT with a coral-like morphology could be applied as a promising electrode material for supercapacitors.

No MeSH data available.