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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.


Electrochemical performance of PEDOT is performed in 1 mol L-1 H2SO4. Mass of the active material =3 mg; (a) CV curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a scan rate of 50 mV s-1. (b) Galvanostatic charge/discharge curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a current density of 3 mA cm-2.
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Figure 6: Electrochemical performance of PEDOT is performed in 1 mol L-1 H2SO4. Mass of the active material =3 mg; (a) CV curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a scan rate of 50 mV s-1. (b) Galvanostatic charge/discharge curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a current density of 3 mA cm-2.

Mentions: The dependence of specific capacitance with potential of the PEDOT powder at a scan rate of 50 mV/s is shown in Figure 6a. All the scans are performed in a potential range from -0.2 to 0.8 V. As depicted in Figure 6a, one pair of redox can be observed for PEDOTs. The relevant anodic and cathodic peaks of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) are (0.46 V, 0.33 V), (0.53 V, 0.34 V), and (0.49 V, 0.35 V), respectively. Compared with PEDOT (6:1) and PEDOT (9:1), it is clear to see the positive shift in the reduction peak potential and the negative shift in the oxidation peak potential of the PEDOT (3:1). Generally, these shifts in anodic and cathodic peak potential can be explained by the higher oxidation degree of PEDOT (3:1) than PEDOT (6:1) and PEDOT (9:1), and the higher oxidation degree leads to an increase in the conductivity of polymer chains, which in turn brings a decrease in the oxidation resistance of the polymer chains. Generally, a method to evaluate the resistance of the electrode material depends on the shape of the capacitance loop of the supercapacitor. The shape of the capacitance loop is almost rectangular, and the electrode material has a lower resistance. On the other hand, the electrode material with high resistance distorts the rectangular shape to become an oblique angle[36]. It is worthy to note that the capacitance loop of PEDOT (3:1) is very close to being rectangular, indicating an excellent capacitance behavior and low internal resistance in the electrode. Moreover, it is observed from Figure 6a that PEDOT (3:1) has the largest rectangular area among the PEDOTs, suggesting that PEDOT (3:1) has better electrochemical behavior and higher capacitance than others.


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)

Electrochemical performance of PEDOT is performed in 1 mol L-1 H2SO4. Mass of the active material =3 mg; (a) CV curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a scan rate of 50 mV s-1. (b) Galvanostatic charge/discharge curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a current density of 3 mA cm-2.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: Electrochemical performance of PEDOT is performed in 1 mol L-1 H2SO4. Mass of the active material =3 mg; (a) CV curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a scan rate of 50 mV s-1. (b) Galvanostatic charge/discharge curves of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) at a current density of 3 mA cm-2.
Mentions: The dependence of specific capacitance with potential of the PEDOT powder at a scan rate of 50 mV/s is shown in Figure 6a. All the scans are performed in a potential range from -0.2 to 0.8 V. As depicted in Figure 6a, one pair of redox can be observed for PEDOTs. The relevant anodic and cathodic peaks of PEDOT (3:1), PEDOT (6:1), and PEDOT (9:1) are (0.46 V, 0.33 V), (0.53 V, 0.34 V), and (0.49 V, 0.35 V), respectively. Compared with PEDOT (6:1) and PEDOT (9:1), it is clear to see the positive shift in the reduction peak potential and the negative shift in the oxidation peak potential of the PEDOT (3:1). Generally, these shifts in anodic and cathodic peak potential can be explained by the higher oxidation degree of PEDOT (3:1) than PEDOT (6:1) and PEDOT (9:1), and the higher oxidation degree leads to an increase in the conductivity of polymer chains, which in turn brings a decrease in the oxidation resistance of the polymer chains. Generally, a method to evaluate the resistance of the electrode material depends on the shape of the capacitance loop of the supercapacitor. The shape of the capacitance loop is almost rectangular, and the electrode material has a lower resistance. On the other hand, the electrode material with high resistance distorts the rectangular shape to become an oblique angle[36]. It is worthy to note that the capacitance loop of PEDOT (3:1) is very close to being rectangular, indicating an excellent capacitance behavior and low internal resistance in the electrode. Moreover, it is observed from Figure 6a that PEDOT (3:1) has the largest rectangular area among the PEDOTs, suggesting that PEDOT (3:1) has better electrochemical behavior and higher capacitance than others.

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.