Quasi-steady-state voltammetry of rapid electron transfer reactions at the macroscopic substrate of the scanning electrochemical microscope.
Quasi-steady-state voltammetry of rapid electron transfer reactions at the macroscopic substrate of the scanning electrochemical microscope.
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DOI：
10.1021/ac102352v
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发表时间：
2011-02-01
影响因子：
7.4
通讯作者：
Amemiya, Shigeru
中科院分区：
文献类型：
--
作者：
Nioradze, Nikoloz;Kim, Jiyeon;Amemiya, Shigeru
我们报告了扫描电化学显微镜（SECM）的新理论和实验，以使宏观底物的快速电子转移（ET）反应的准稳态伏安法具有这种强大的方法。氧化还原夫妇分别在反馈或底物生成/尖端收集模式下在尖端检测到底物反应的反应物或产物。电流与底物的电位具有准稳态伏安图的可矫正乙状结肠形状，尽管在宏观底物上获得了瞬态伏安图。是准稳态的伏安法所必需的。可靠地确定了所有转运，热力学和动力学参数，作为在PT底物的PT底物上的快速ET反应和7,7,8,8,8,8,8,8,8,8,8,8-8,8-四甲苯二甲烷，约为0.5-μm-μm-radius pt尖端，位于90 nm –1μm-1μm-1μm-–1μm-–1μm-–1μm-–1μm-–1μm-–1μm 。还提出了准稳态伏安法。
We report on novel theory and experiment for scanning electrochemical microscopy (SECM) to enable quasi-steady-state voltammetry of rapid electron transfer (ET) reactions at macroscopic substrates. With this powerful approach, substrate potential is cycled widely across the formal potential of a redox couple while the reactant or product of a substrate reaction is amperometrically detected at the tip in the feedback or substrate generation/tip collection mode, respectively. The plot of tip current versus substrate potential features the retraceable sigmoidal shape of a quasi-steady-state voltammogram although a transient voltammogram is obtained at the macroscopic substrate. Finite element simulations reveal that a short tip–substrate distance and a reversible substrate reaction (except under the tip) are required for quasi-steady-state voltammetry. Advantageously, a pair of quasi-steady-state voltammograms is obtained by employing both operation modes to reliably determine all transport, thermodynamic, and kinetic parameters as confirmed experimentally for rapid ET reactions of ferrocenemethanol and 7,7,8,8-tetracyanoquinodimethane at a Pt substrate with ∼0.5-μm-radius Pt tips positioned at 90 nm–1 μm distances. Standard ET rate constants of ∼7 cm/s were obtained for the latter mediator as the largest determined for a substrate reaction by SECM. The various potential applications of quasi-steady-state voltammetry are also proposed.
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影响因子：
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作者：
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通讯作者：
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影响因子：
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