In situ Ru K-edge X-ray absorption fine structure studies of electroprecipitated ruthenium dioxide films with relevance to supercapacitor applications

Yibo Mo, Mark R. Antonio, Daniel Alberto Scherson*

*この研究の対応する著者

研究成果: Article査読

60 被引用数 (Scopus)

抄録

Modifications in electronic and structural aspects of RuO2 films electroprecipitated onto Au electrodes induced by changes in the applied potential have been examined in situ in aqueous 0.50 M H2SO4 by Ru K-edge X-ray absorption spectroscopy (XAS). The Fourier transform of the k3-weighted extended X-ray absorption fine structure (EXAFS), k3χ(k), for the film polarized at +1.20V vs RHE is characterized by two shells attributed to Ru-O and Ru-Ru interactions with average distances of 1.94(1) and 3.12(2) Å, respectively, in agreement with results obtained ex situ for Ru4+ in hydrous RuO2 by other groups. In contrast, films in the reduced state, i.e., +0.40 V vs RHE, yielded only a single shell ascribed to a Ru-O interaction at 2.02(1) Å with no evidence for a distant Ru-Ru shell. The long Ru-O distance is in agreement with that reported earlier for the hydrous Ru3+ ion [Ru-(OH2)6]3+ in the solid state. Moreover, the difference between the average Ru-O bond lengths for the reduced and oxidized films is consistent with the difference in the ionic radii of Ru3+ and Ru4+. On this basis it has been suggested that films in the reduced state contain Ru3+ sites, consistent with the electrochemical results, in a phase with apparently less order beyond the Ru-O coordination sphere than for hydrous RuO2.

本文言語English
ページ(範囲)9777-9779
ページ数3
ジャーナルJournal of Physical Chemistry B
104
42
出版ステータスPublished - 2000 10月 26
外部発表はい

ASJC Scopus subject areas

  • 表面、皮膜および薄膜
  • 物理化学および理論化学
  • 材料化学

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