A detailed electrochemical impedance spectroscopy study of a bismuth-film glassy carbon electrode for trace metal analysis
A detailed electrochemical impedance spectroscopy study of a bismuth-film glassy carbon electrode for trace metal analysis
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DOI：
10.1016/j.aca.2017.12.020
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发表时间：
2018-04-03
影响因子：
6.2
通讯作者：
Finsgar, Matjaz
中科院分区：
文献类型：
--
作者：
Petovar, Barbara;Xhanari, Klodian;Finsgar, Matjaz
本文报道了在0.1M醋酸盐缓冲溶液中原位制备的铋膜玻碳电极在不同电位下的电化学阻抗谱。该电极用于方波阳极溶出伏安法（SWASV）测定痕量重金属Zn、Cd和Pb。首先对该方法的检测限、线性范围、灵敏度、精密度和准确度进行了验证，以明确证明BiFE与裸玻碳电极（GCE）相比具有上级作用。接下来，为了研究该传感器的特性，在不同沉积电位下的沉积步骤之后，在比检测每个单独剥离信号的电位略负的电位下进行EIS测量。为了比较，还在开路电位下进行EIS测量。所研究的痕量金属浓度范围（5-20 ppb）没有显著影响BiFE的电容和电阻行为，这解释了为什么该传感器的性能上级裸GCE。较高的灵敏度的SWASV方法BiFE相比，裸GCE解释了较低的极化电阻值的前。此外，还确定了零电荷电位，并对该体系是否处于动力学和/或扩散控制过程给出了解释。(c)2017爱思唯尔B. V.保留所有权利。
A systematic electrochemical impedance spectroscopy (EIS) analysis at different potentials of an in situ-prepared bismuth-film glassy carbon electrode (BiFE) in 0.1M acetate buffer solution is reported. This electrode is employed in the square-wave anodic stripping voltammetry (SWASV) technique for the determination of trace amounts of the heavy metals Zn, Cd, and Pb. The method was first validated for detection limit, linear range, sensitivity, precision and accuracy to clearly prove the superior action of BiFE compared with the bare glassy carbon electrode (GCE). Next, in order to investigate the characteristics of this sensor, EIS measurements were carried out at slightly more negative potentials than the potentials at which each individual stripping signal is detected, after the deposition step at different deposition potentials. For comparison, EIS measurements were also performed at open circuit potential. The studied trace metal concentration range (5-20 ppb) did not significantly influence the capacitive and resistive behaviour of the BiFE which explains why the performance of this sensor is superior compared with the bare GCE. The higher sensitivity of the SWASV method for BiFE compared with the bare GCE was explained by the lower polarisation resistance values of the former. Moreover, the potential of zero charge was also determined, and an explanation whether the system is under kinetic-and/or diffusion-controlled process is given. (c) 2017 Elsevier B.V. All rights reserved.