Controlling the mixed potential of polyelectrolyte-coated platinum electrodes for the potentiometric detection of hydrogen peroxide
Controlling the mixed potential of polyelectrolyte-coated platinum electrodes for the potentiometric detection of hydrogen peroxide
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DOI：
10.1016/j.aca.2019.11.018
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发表时间：
2020-02-08
影响因子：
6.2
通讯作者：
Andrade, Francisco J.
中科院分区：
文献类型：
--
作者：
Baez, Jhonattan F.;Compton, Matthew;Andrade, Francisco J.
在以前的工作中，已经描述了使用涂覆有一层Nation的Pt电极作为进行过氧化氢的电位检测的有吸引力的方式。尽管这种方法的吸引力的特点，这个系统的非能斯特响应的性质没有得到适当的解决。在这项工作中，使用混合电位模型，开路电位的Pt电极被证明是下的氧还原反应（ORR）的动力学控制。有人提出，过氧化氢作为一种氧化物质，阻止Pt表面上的自由网站，干扰ORR。因此，可以根据影响ORR动力学的因素的调节来理解涂层的效果，例如H +浓度的增加、旁观者物种的影响的最小化等。由于复杂性和缺乏准确描述具有实际应用的系统的模型，这项工作并不打算提供一个机械的，而是一个现象学的观点对问题。一个一般的框架，以了解影响电位响应的因素。实验证据表明，使用双金属涂层是一种控制混合电位的有效方法，为开发耐用且简单的电位传感器开辟了新途径。(C)2019爱思唯尔B.V.保留所有权利。
The use of a Pt electrode coated with a layer of Nation has been described in previous works as an attractive way to perform the potentiometric detection of hydrogen peroxide. Despite of the attractive features of this approach, the nature of the non-Nernstian response of this system was not properly addressed. In this work, using a mixed potential model, the open circuit potential of the Pt electrode is shown to be under kinetic control of the oxygen reduction reaction (ORR). It is proposed that hydrogen peroxide acts as an oxygenated species that blocks free sites on the Pt surface, interfering with the ORR. Therefore, the effect of the polyelectrolyte coating can be understood in terms of the modulation of the factors that affects the kinetics of the ORR, such as an increase of the H + concentration, minimization of the effect of the spectator species, etc. Because of the complexity and the lack of models that accurately describe systems with practical applications, this work is not intended to provide a mechanistic but rather a phenomenological view on problem. A general framework to understand the factors that affect the potentiometric response is provided. Experimental evidence showing that the use of polyelectrolyte coatings are a powerful way to control the mixed potential open new ways for the development of robust and simple potentiometric sensors. (C) 2019 Elsevier B.V. All rights reserved.