Electrochemical Properties and Application of Mixed Silver‐Bismuth Electrodes

Abstract

Electrochemical properties of silver electrodes with 2, 4, 6, 10 and 15% bismuth have systematically been investigated with cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Increased overpotential towards hydrogen evolution reaction (HER) was found as a result of increasing amount of added bismuth. This was also demonstrated in acid solution where zinc was successfully detected on mixed electrodes, but failed on pure silver electrodes. Formation and decomposition of oxide products formed on the different electrode surfaces were studied by cyclic voltammetry, and in addition to known species found on sliver, also peaks attributed to bismuth were achieved and examined. Zinc, cadmium, and lead were measured in the low mg/L range on the mixed electrodes, and good linearity (r 2 ¼ 0.998) was found for 2 to 10 mg/L. Lead was measured down to 0.1 mg/L. Further it was found in DPASV that the zinc peak significantly shifted towards a more negative value with increasing amount of bismuth in the silver electrodes. The same was also observed for cadmium and lead, but in a less extent. Finally a silver electrode containing 15% bismuth was used for continuous analyses in a polluted river for 6 weeks.

Voltammetric procedure for trace metal analysis in polluted natural waters using homemade bare gold-disk microelectrodes

“…Another attempt with Ir microelectrodes with only traces of mercury was successful for Pb and Cd determination and measurements in box-core sediments [16]. Preparation for in-field measurements has been carried out on gold electrodes in acidic solutions [17,18], solid dental amalgam electrodes [19,20] and alloys [21]. KirowaEisner's team [22][23][24][25][26][27] researched solid bare silver and gold electrodes of macro scale, contributing to a better understanding and application of underpotential deposition (UPD) effects in stripping voltammetry [28].…”

A Decade with Bismuth‐Based Electrodes in Electroanalysis

“…Such a sharp increase in publication rate, as well as the abundance of debuting research groups (e.g., [49,51,54,61] or [64]) makes the characterization of the individual activities more difficult; nevertheless, certain relations and typical trends can be highlighted. In general, it can be stated that all major activities started in the previous years had intensive continuation.…”

“…The respective morphologies were shown to be markedly diversified and transformable into different structures that influenced the electroanalytical performance of the resultant electrodes more than was known for related mercury films. Also, the microstructure of bismuth-containing layers started to be the subject of characterizations via electrochemical impedance spectroscopy (EIS [50,51]). Of continuing interest was the robust configuration of the BiBE [48], along with other electrode substrates for bismuth films, such as graphite-epoxy composite [49], electrogenerated carbon films [50], boron-doped diamond [53], screen-printed carbon inks [55], and new types of carbon fibers [56].…”

“…Of continuing interest was the robust configuration of the BiBE [48], along with other electrode substrates for bismuth films, such as graphite-epoxy composite [49], electrogenerated carbon films [50], boron-doped diamond [53], screen-printed carbon inks [55], and new types of carbon fibers [56]. Completely new types of bismuth electrodes were also proposed based on heterogeneous mixtures of bismuth with another metal [51] or a carbon paste matrix with a fine bismuth powder admixed in [62,67,69]. Furthermore, various mini- [59] and microconfigurations [57,66] were also tested, including the first prototype of a three-electrode integrated cell [55] assembled and machined with the aid of screen-printing technology.…”

“…Of course, the mid-2000s witnessed also significant advances in the development and optimization of new (or newly adapted) methods of practical electroanalysisherein, one can quote contributions concerning the determination of Zn(II), Cd(II), and Pb(II) in water samples [49,51,62], soils [49], milkvetch [54], or plant extracts [66]. Some efforts to identify -and, subsequently, eliminate -the Cu(II) ions [55,67] are notable because of the fact that the respective signal occurs out of the operational potential window of a BiE, but can be detected and quantified using procedures employing BiFEs in situ.…”