open access

https://hdl.handle.net/2115/68046

Spectroelectrochemical evidence of the role of viologen moiety as an electron transfer mediator from ITO substrate to a Pt complex acting as a confined molecular catalyst for hydrogen evolution reaction

英語

Hydrogen evolution reaction

2016-01

Elsevier

Electrochemistry Communications

62

56-59

Spectroelectrochemical measurements at indium tin oxide (ITO) electrode modified with viologen monolayer showed two redox peaks corresponding to viologen dication/radical cation (V2 +/V+radical dot) and viologen radical cation/neutral form (V+radical dot/V0) in cyclic voltammogram (CV), and stable spectra corresponding to radical cation (V+radical dot) and neutral form (V0) of viologen at potentials between V2 +/V+radical dot and V+radical dot/V0 redox peaks and those more negative than V+radical dot/V0 redox peak, respectively. On the other hand, at viologen monolayer modified ITO electrode with Pt complex confined within the monolayer by ion exchange reaction, no redox peaks but large current due to hydrogen evolution reaction (HER) were observed in CV and no absorption peaks corresponding to V+radical dot or V0 were observed in the UV/visible spectra obtained during the potential scan. Time-resolved spectroelectrochemical measurements, however, showed that V+radical dot is formed upon the potential step to the potentials more negative than V2 +/V+radical dot redox potential and disappeared within ca. 1 ms, showing that electron is transferred from ITO electrode to proton to form hydrogen via viologen moiety and Pt complex.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

© 2016, Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

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