FTIR spectroscopic characterization of thermally treated Cu2+, Cd2+, and Li+ montmorillonites

Exfoliated nanocomposites of poly(3,4-ethylenedioxythiophene) (PEDOT) and montmorillonite (MMT) have been prepared by in situ anodic polymerization, concentrations of clay ranging from 5% w/w to 50% w/w being included in the aqueous polymerization medium. The morphology, electrical conductivity, adherence, thermal stability, charge storage, specific capacitance, electrostability, doping level and band gap have been determined for the different PEDOT-MMT nanocomposites and compared with those of pristine PEDOT. Many of these properties have been found to depend on both the concentration of clay and the thickness (micrometric or nanometric) of the generated films. Types I and II ultracapacitors have been fabricated using nanometric and micrometric films of PEDOT and PEDOT-MMT. The properties of such devices have been characterized and compared with those reported in the literature for ultracapacitors fabricated using nanocomposites of PEDOT and other inorganic materials. Both nanometric and micrometric type II ultracapacitors, which correspond to an asymmetric configuration of PEDOT and PEDOT-MMT films, have been found to present the better properties (e.g. the specific capacitance for nanometric and micrometric devices is 429 and 116 F g À1 , respectively), evidencing the favorable effect of the clay. Finally, the effects of the electrochemical degradation on the ultracapacitors have been rationalized using electrochemical impedance spectroscopy.

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“…54 As expected, the spectra of PEDOT-MMT nanocomposites exhibited the characteristic bands of PEDOT in the range of 1052-837 cm…”

supporting

confidence: 77%

Hybrid polythiophene–clay exfoliated nanocomposites for ultracapacitor devices

et al. 2012

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“…Each time, after exchange, the zeolite powder was washed repeatedly with distilled water and then dried. By analogy with an earlier report [27], cation exchange capacities were determined by extraction of exchangeable cations with 1 M ammonium ac- Table 3 Percentage yield a and product formation in reduction of mixture of arenes with two different functionalities b etate solution at pH = 7.0. Fifty milligram of the zeolite sample was shaken with 10 ml of ethanol, 10 ml of ammonium acetate solution was added, and the extracts were collected after 24 h. Ten milliliter of distilled water added to the solids and the extracts were collected after an additional 24 h. This process was repeated at least five times, and all extracts obtained from the same sample were combined and analyzed by atomic absorption spectroscopy (AAS).…”

Section: Methodsmentioning

confidence: 99%

Simple and efficient reduction of nitroarenes by hydrazine in faujasite zeolites

Kumarraja

Pitchumani

2004

Applied Catalysis A: General

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“…The trivalent Cr 3+ behaved differently from the divalent Cu 2+ and Cd 2+ . The difference between Cu 2+ , Cd 2+ and Cr 3+ at the O-H band was due to the different charges and ionic radii of the heavy metals (Madejov et al, 1999). The strong band near 1034 cm −1 was attributed to the Si-O vibrations of the tetrahedral sheet and the absorption peak near 1086 cm −1 was the Si-O vibrations of amorphous silica with a threedimensional framework (Madejov, 2003).…”

Section: Ftir Analysismentioning

confidence: 99%