ELECTRON-TRANSFER REACTIONS ON PASSIVE CHROMIUM
ELECTRON-TRANSFER REACTIONS ON PASSIVE CHROMIUM
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DOI：
10.1149/1.2069049
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发表时间：
1992-11-01
影响因子：
3.9
通讯作者：
BARD, AJ
中科院分区：
文献类型：
--
作者：
MOFFAT, TP;YANG, HJ;BARD, AJ
电化学钝化铬和几个外层氧化还原电对之间的电子转移的动力学已被研究作为钝化膜厚度的函数，d = 5至25埃，在1M H2SO4。表观电子转移速率随钝化层厚度的增加呈指数下降。类似地，在恒电位膜生长期间，由于d随log（t）而变化，因此作为膜生长动力学的结果，电子转移速率随时间t以曲线方式降低。这些关系表明电子隧穿控制的过程。然而，薄膜厚度和缺陷的变化导致电子转移发生在隧道概率增强的分布位置，使得有意义的定量分析变得困难。
The kinetics of electron transfer between electrochemically passivated chromium and several outer-sphere redox couples have been investigated as a function of passive-film thickness, d = 5 to 25 angstrom, in 1M H2SO4. The apparent rate of electron transfer decreased exponentially with increasing thickness of the passivating overlayer. Similarly, during potentiostatic film growth, the electron-transfer rate decreased logarithmically with time, t, as a consequence of the film-growth kinetics, since d varies with log(t). These relationships indicate an electron-tunneling controlled process. However, variations in the film thickness and defects result in electron transfer occurring at distributed sites of enhanced tunneling probability, making a meaningful quantitative analysis difficult.