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Time-resolved ESR investigation on energy transfer processes in Nafion photochemistry
- Source :
- International Journal of Hydrogen Energy. 37:6317-6325
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
Abstract
- A solid film of Nafion has been prepared on the inner wall of a quartz tube. After pulsed photoexcitation, time-resolved electron spin resonance (TR-ESR) spectra have been recorded in the temperature range of 290–15 K. The spectra exhibit strongly electron-spin polarized signals in full absorption arising from the excited triplet state of Nafion. The absence of any resolved spectral features and the unusual narrowing of the TR-ESR signal linewidth with decreasing temperature are discussed in terms of the spin Hamiltonian of an excited triplet state with dynamic dipole–dipole interactions between the two unpaired electron spins. The existence of a triplet–triplet energy transfer process is considered, and a prominent role of hydrogen bonds of the surrounding water network is suggested. Finally, the time evolutions of the TR-ESR signals have been analysed, and the corresponding decay parameters have been obtained at low temperatures. Our results provide insight on the role of water as a medium for the conductivity mechanism in Nafion membranes.
- Subjects :
- energy transfer
Spins
Renewable Energy, Sustainability and the Environment
Polymer electrolyte
Nafion membrane
ESR spectroscopy
Electron spin polarization
Mobile excited triplet state
Energy Engineering and Power Technology
Atmospheric temperature range
Condensed Matter Physics
Photochemistry
law.invention
Photoexcitation
chemistry.chemical_compound
Fuel Technology
chemistry
Unpaired electron
law
Nafion
Excited state
Condensed Matter::Strongly Correlated Electrons
Triplet state
Electron paramagnetic resonance
Subjects
Details
- ISSN :
- 03603199
- Volume :
- 37
- Database :
- OpenAIRE
- Journal :
- International Journal of Hydrogen Energy
- Accession number :
- edsair.doi.dedup.....2d7f2ab4d194f5d7784c43254fe80439