In situ Evolved Gas Analysis of TMOS-based Gel Electrolytes Containing Guanidinium Thiocyanate for Quasi-solid-state Dye-sensitized Solar Cells by TG-FTIR and TG-MS

  • Viola Nagygyörgy Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, HU-1111 Budapest, Szt. Gellért tér 4, Hungary
  • Elias Stathatos Nanotechnology and Advanced Materials Laboratory, Technological-Educational Institute of Western Greece, 26334 Patras, Greece
  • György Pokol Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, HU-1111 Budapest, Szt. Gellért tér 4, Hungary; Research Centre for Natural Sciences, Hungarian Academy of Sciences, HU-1117 Budapest, Magyar tudósok körútja 2, Hungary
  • János Madarász Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, HU-1111 Budapest, Szt. Gellért tér 4, Hungary

Abstract

A comparative study on thermal stability of hybrid (organic / inorganic) electrolytes for dye-sensitized solar cells (DSSCs) in various ethylene oxide oligomers / silica based gelly matrices, containing also some efficiency-promoter additives is presented. Using thermogravimetry combined with two evolved gas analytical (EGA-FTIR and EGA-MS) techniques, the released gases and volatile decomposition products from the composite electrolytes during dynamic heating programs have been identified and monitored. First methanol (arising from condensation of tetramethoxysilane, TMOS) and acetonitrile (solvent) are evolved followed by elongated release of 4-tert-butylpyridine, than carbonyl sulfide, which is one of the degradation products of guanidinium thiocyanate, and various alkyl iodides, as well as iodine, later various oxidized species with >C=O groups (arising from oxidative degradation of oligo(ethylene glycolic) parts, ammonia (originated from guanidine) have been observed and traced during the accelerated heating tests, before final burning out of the organic residue with CO2 evolution. Thermal behavior of pure guanidinium thiocyanate, one of the most important additives improving thermal stability of Grätzel type solar cells (DSSCs), combined with identification of its eight gaseous decomposition products and their release pattern is also reported.

Keywords: Grätzel type, dye-sensitized solar cell (DSSC), coupled evolved gas analysis (EGA), guanidinium thiocyanate, tetramethoxysilane (TMOS), thermogravimetry (TG), Triton X-100, PEG 200, Q-MS, FTIR-spectroscopic gas cell
Published online
2018-11-05
How to Cite
Nagygyörgy, V., Stathatos, E., Pokol, G. and Madarász, J. (2018) “In situ Evolved Gas Analysis of TMOS-based Gel Electrolytes Containing Guanidinium Thiocyanate for Quasi-solid-state Dye-sensitized Solar Cells by TG-FTIR and TG-MS”, Periodica Polytechnica Chemical Engineering, 62(4), pp. 533–545. doi: https://doi.org/10.3311/PPch.12820.
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Articles