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Supporting electrolyte
About: Supporting electrolyte is a research topic. Over the lifetime, 5011 publications have been published within this topic receiving 104172 citations.
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TL;DR: Results indicate that electrocoagulation with iron anodes is a rapid, economical and effective alternative to the complete removal of CV in waters.
51 citations
TL;DR: The electrochemical behavior of the cation exchange polymer Nafion containing tetrathiafulvalenium (TTF+) on a platinum substrate is described in this paper, where very narrow cyclic voltammetric waves are observed that result in part from attractive interactions between the electroactive molecules.
Abstract: The electrochemical behavior of the cation exchange polymer Nafion containing tetrathiafulvalenium (TTF+) on a platinum substrate is described. The polymer electrode shows cyclic voltammetric behavior similar to that of solid films of TTF on platinum. In the oxidized form of the electroactive molecules in the polymer (TTF+) forms nonstoichiometric complexes with Br−. The peak potentials in cyclic voltammetry shift with changes in concentration of supporting electrolyte, temperature, and anion of the supporting electrolyte. Very narrow cyclic voltammetric waves are observed that result in part from attractive interactions between the electroactive molecules. The separation in peak potential of the reduction and oxidation waves is explained by formation of which stabilizes the oxidized form (TTF+) and makes it harder to reduce. Peak potentials for the oxidation and reduction shift closer together as the scan rate is lowered, which is explained by a "square (reaction) scheme."
51 citations
TL;DR: Voltammetric sensors for K(+, Na(+), and Ca(2+) constructed in this manner exhibit the sensitivity and selectivity required for determination of these ions in environmentally and biologically important matrixes.
Abstract: A general theory has been developed for voltammetric ion sensing of cations and anions based on the use of an electrode coated with a membrane containing an electroactive species, an ionophore, and a supporting electrolyte dissolved in a plasticizer. In experimental studies, a membrane coated electrode is fabricated by the drop coating method. In one configuration, a glassy carbon electrode is coated with a poly(vinyl chloride) based membrane, which contains the electroactive species, ionophore, plasticizer and supporting electrolyte. In the case of a cation sensor, ionophore facilitated transfer of the target cation from the aqueous solution to the membrane phase occurs during the course of the reduction of the electroactive species present in the membrane in order to maintain charge neutrality. The formal potential is calculated from the cyclic voltammogram as the average of the reduction and oxidation peak potentials and depends on the identity and concentration of the ion present in the aqueous solution phase. A plot of the formal potential versus the logarithm of the concentration exhibits a close to Nernstian slope of RT/F millivolts per decade change in concentration when the concentration of K(+) and Na(+) is varied over the concentration range of 0.1 mM to 1 M when K(+) or Na(+) ionophores are used in the membrane. The slope is close to RT/2F millivolts for a Ca(2+) voltammetric ion-selective electrode fabricated using a Ca(2+) ionophore. The sensor measurement time is only a few seconds. Voltammetric sensors for K(+), Na(+), and Ca(2+) constructed in this manner exhibit the sensitivity and selectivity required for determination of these ions in environmentally and biologically important matrixes. Analogous principles apply to the fabrication of anion voltammetric sensors.
51 citations
TL;DR: In this paper, a thin film of zinc hexacyanoferrate (ZnHCF) was formed directly on a Zn electrode to prepare a chemically modified electrode, which was stable against gradual dissolution during potential cycling and long-term usage.
51 citations
TL;DR: Comparison between the direct electroreduction of aryldiazonium compounds on a platinum electrode and their reaction with [Pt2-, Na+, NaI] suggests that a similar general mechanism is responsible for the grafting.
Abstract: Platinum phases of general formula [Pt(n-), M+, MX] can be electrogenerated from cathodic polarization in dry dimethylformamide containing a supporting electrolyte, MX. The reaction of these electrogenerated Pt phases as reducing agent with aryldiazonium salts was investigated for preparing controlled metal-organic interfaces and characterizing the reactivity of the "reduced platinum phases". In a two-step process, the "reduced platinum phase" locally reacts with aryldiazonium salts, leading to the attachment of aryl groups onto the metal surface in the previously modified areas. Detailed experiments using cyclic voltammetry, X-ray photoelectron spectroscopy (XPS), and in situ electrochemical atomic force microscopy (EC-AFM) were carried out to follow the reaction in solution with the example of NaI as supporting electrolyte (MX = NaI). These studies demonstrate the irreversible attachment of aryl groups onto the platinum electrode. Comparison between the direct electroreduction of aryldiazonium compounds (4-nitrophenyl- and 4-bromophenyldiazonium) on a platinum electrode and their reaction with [Pt2-, Na+, NaI] suggests that a similar general mechanism is responsible for the grafting. However in the second case, no applied potential is required to stimulate the binding thanks to the reductive properties of [Pt2-, Na+, NaI]. Competitive reduction of the organic layer and growth of the layer were observed and analyzed as a function of the injected charge used to initially produce [Pt2-, Na+, NaI]. Similar reactions are highly probable with other MX salts owing to the redox properties observed for this type of platinum phase ([Pt(n-), M+, MX]).
51 citations