In Situ Ru K-Edge X-Ray Absorption Fine Structure Studies of Electroprecipitated Ruthenium Dioxide Films with Relevance to Supercapacitor Applications
In Situ Ru K-Edge X-Ray Absorption Fine Structure Studies of Electroprecipitated Ruthenium Dioxide Films with Relevance to Supercapacitor Applications
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DOI：
10.1021/jp002355a
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发表时间：
2000-09
影响因子：
3.3
通讯作者：
Y. Mo;A. M. Antonio;D. Scherson
中科院分区：
文献类型：
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作者：
Y. Mo;A. M. Antonio;D. Scherson
在电子和结构方面的改性的RuO2膜电沉积到Au电极上所施加的电位的变化引起的已检查原位在0.50 M的H2SO4水溶液中由Ru K边X射线吸收光谱（XAS）。在+1.20 V vs. RHE极化的薄膜的k3加权扩展X射线吸收精细结构（EXAFS）的傅里叶变换，k3χ（k），其特征在于两个壳归因于Ru−O和Ru−Ru相互作用，平均距离分别为1.94（1）和3.12（2）A，与其他小组对水合RuO2中Ru 4+的非原位结果一致。相反，处于还原状态的膜，即，+0.40 V vsRHE，在2.02（1）A处只产生了一个归因于Ru−O相互作用的单一壳层，没有证据表明有一个遥远的Ru−Ru壳层。长的Ru−O距离与先前报道的固态水合Ru 3+离子[Ru−（OH2）6]3+的距离一致。此外，还原膜和氧化膜的平均Ru−O键长之间的差异是一致的。
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) A, 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) A 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 consis...