Interdigitated array electrode as an alternative to the rotated ring-disk electrode for determination of the reaction products of dioxygen reduction
Interdigitated array electrode as an alternative to the rotated ring-disk electrode for determination of the reaction products of dioxygen reduction
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DOI：
10.1021/ac960327b
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发表时间：
1996-09-01
影响因子：
7.4
通讯作者：
Amatore, C
中科院分区：
文献类型：
--
作者：
Postlethwaite, TA;Hutchison, JE;Amatore, C
水介质中双氧水的电化学还原可以进行到水、过氧化氢或两者的混合物，过氧化氢的产生也可以在交指阵列(IDA)电极上进行定量评估，其中在微带发生器电极组处还原双氧水，并且通过在交叉指收集器电极组处的氧化(回到02)来检测产生的任何过氧化氢。由于其更完整的收集，以及随后O-2的再生，从而导致发生器电流的放大，因此，H_2O_2的产生既反映在集电极电流和发生器电极电流的比率[收集效率，coll(Tau)]上，也反映在集电极电位开启和关闭时的发电机电流的比率[放大系数，Ampl(Tau)]。基于保角映射技术，给出了解释氧还原产生的H_2O_2的分数epsilon的必要理论。导出了epsilon在长时间内的显式方程，该方程与IDA维度无关，可用于任何类似于氧气还原的两产物电化学反应。给出了在酸性和碱性介质中氧气还原的实验数据，以说明理论的应用。
Electrochemical reduction of dioxygen in aqueous media can proceed to water, hydrogen peroxide, or a mixture of the two, The production of hydrogen peroxide, classically established with the rotated ring-disk electrode, can also be quantitatively assessed at interdigitated array (IDA) electrodes, where dioxygen is reduced at the set of microband generator electrodes and any H2O2 produced is detected by its oxidation (back to 02) at the interdigitated set of microband collector electrodes, The sensitivity of the IDA for H2O2 detection is higher owing to its more complete collection, and to the ensuing regeneration of O-2, which leads to an amplification of the generator currents, The production of H2O2 is thus reflected both in the ratio of collector and generator electrode currents [the collection efficiency, coll(tau)] and in the ratio of the generator current with the collector potential on to that with it off [amplification factor, ampl(tau)]. The necessary theory for interpretation of the fraction epsilon of H2O2 produced per dioxygen reduced is presented, based on conformal mapping techniques. Explicit equations are derived for epsilon at long times that are independent of the IDA dimensions and that can be used with any two-product electrochemical reaction analogous to the dioxygen reduction. Experimental data are presented for dioxygen reduction in acidic and basic media to illustrate application of the theory.