A Novel Approach To Prepare Poly(3,4-ethylenedioxythiophene) Nanoribbons between V2O5 Layers by Microwave Irradiation

Rapid synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) nanoribbons interleaved between the layers of crystalline V2O5 is achieved for the first time under microwave irradiation via the redox intercalative polymerization reaction of 3,4-ethylenedioxythiophene (EDOT) monomer and crystalline V2O5 at different time intervals. Compared with the conventional 12 h of refluxing for intercalative polymerization, the microwave-assisted redox polymerization process proceedes rapidly, enabling the expansion of the interlayer spacing of crystalline V2O5 from 0.43 to 1.41 nm within 8 min. The characterization of this material using powder XRD, XPS, EPR, SEM, and HRTEM analysis supports the intercalation of the polymer between V2O5 layers, leading to enhanced bidimensionality. XPS analysis clearly shows the presence of mixed-valent V4+/V5+ in the V2O5 framework after the redox intercalative polymerization, which also confirms charge transfer from the polymer to the V2O5 framework. EPR study also reveals redox processes during EDOT insertion and polymerization between the V2O5 layers. After PEDOT insertion into V2O5, the EPR signal from VO2+ is more pronounced as the intensity of the signal increases as compared to that of pristine V2O5. This nanocomposite when coupled with a large-area Li foil electrode in 1 M LiClO4 in a mixture of ethylene and dimethyl carbonate (1:1 by volume) gives a discharge capacity of ∼350 mA h g-1, which is significantly higher than that of pristine V2O5.