Silver reference electrode

Fig. 12. Absorption spectra of polyaniline film on a semitransparent Pt electrode immersed in 1 M HC1. Spectra (a) to (f) were recorded at potentials of —0.2, +0.6, +0.8, + 1.0, + 1.2 and + 1.4 V relative to a silver reference electrode. Reproduced from [173b],...

A 9 cm-1 upshift of the tangential mode (G band) vibrational frequency as well as a 90% decrease in intensity was observed by applying 1.0 V between an individual nanotube and a silver reference electrode in a dilute sulfuric acid solution. 

In order to confirm such potential shift we observed the actual behavior of the sensing and counter electrode potential under both open and short circuit conditions. Each potential was measured against a silver reference electrode which was attached to the sensor element as shown in Figure 6. Figure 7 depicts the response curves against 500 ppm H2 in air under both conditions. When the circuit is open, the change in potential occurs only at the sensing... 

Copper(II) and cerium(IV) have been studied as oxidants in acetonitrile. The copper(II)-copper(I) couple has an estimated electrode potential of 0.68 V relative to the silver reference electrode. It has been studied as an oxidant for substances such as iodide, hydroquinone, thiourea, potassium ethyl xanthate, diphenylbenzidine, and ferrocene. Cerium(IV) reactions are catalyzed by acetate ion. Copper(I) is a suitable reductant for chromium(VI), vanadium(V), cerium(IV), and manganese(VII) in the presence of iron(III). For details on many studies of redox reactions in nonaqueous solvents, the reader is referred to the summary by Kratochvil. ... 

Characteristic features of the construction of the reference electrodes mentioned consist in the materials serving as current taps. Platinum is used with silver reference electrodes, but cannot be used for lead electrodes since the lead forms alloys with Pt and the current taps are destroyed by such interactions. This requires the use of iron or tungsten wires as intermediate current-tap materials. The potentials of the mentioned reference electrodes are highly reproducible, and they were extensively and thoroughly studied over a wide range of temperatures and concentrations in potentiometric cells of the following kinds ... 

Coefficients of the E = E0 + kpm calibration dependences obtained against silver reference electrode (AglAg+, 0.2 mol kg-1) in the molten KCl-NaCl equimolar mixture at 700 °C... 

Figure 13(b) depicts typical force curves that were obtained when the interaction between neutral polymer films (both tip and substrate biased at —0.25 V versus polished silver reference electrode) and oxidized polymer films [E = -F0.30 V) was measured. Statistical analysis of over 100 consecutive approach and retract plots yielded an average adhesive force of... 

Linear sweep voltammetry was used, with the convolution technique. A silver chloride-silver reference electrode was employed. The working electrode was a tungsten wire (I mm in diameter). The counter electrode was either a carbon rod or the graphite crucible. 

T = 1123 K S = 0.196 cm ). Curves are shifted along the current axis they were obtained at 30-s intervals, E is given with respect to silver reference electrode. 

Flengas and coworkers [2,3] have measured the equilibrium potentials of chromium in a molten equimolecular mixture of sodium and potassium chlorides at various concentrations of its ions, based on the ratio to a silver reference electrode. They determined [2,3] the standard electrode potentials E cr(ii)/Cn E°ci(niycr and the redox potential E°cr(m)/cr(U)-... 

In 1963, Caton and Freund (75) made preliminary voltammetric studies of a number of redox systems in molten alkali metal metaphosphates, but the work was limited by the lack of a reference electrode. In 1971 Wolfe and Caton (76) devised a silver reference electrode which was applied to potentiometric and chronopotentiometric studies in equimolar mixtures of sodium and potassium metaphosphates at 700 C of several redox couples. Diffusion coefficients and standard potentials were evaluated. 

A limited amount of electroanalytical work has been done in sulfate melts. The oxygen electrode has been mentioned above for alkaline melts. In 1961, Liu (77,78) applied potentiometry, chronopotentiometry and coulometric titrations in lithium sulfate-potassium sulfate melts at 625°C using a silver reference electrode. An electromotive force series of limited scope and... 

All redox couples in mV versus silver reference electrode at 10 mV/s scan rate. ° Peak to peak separation for each redox couple in mV. 

The reference electrode normally has a slow leak into the solution at a rate of a few microlitre per hour. It is therefore advisable to ensure the filling solution (normally 3 mol/L KCl) is clean, either by using a high grade salt for its preparation, or by piuification. Double-junction reference electrodes exist and these are useful for instance if silver or sulphide are to be determined due to the presence of ionic silver in the silver reference electrode cartridge. 

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