Reference electrodes AglAgCl

A potentiostatic, three-electrode circuit allows the separation of both functions physically for the reference potential, a non-polarisable electrode is used (a calomel or AglAgCl reference electrode), while the electrical-current conducting electrode is an inert metal electrode. With electrochemical, direct-current methods, the effect of this modification is limited to a reduction of the so-called IR-drop (or ohmic-drop), which is caused by... 

FIGURE 5>4 A schematic of the flow-through immunosensor equipped with (1) fluid inlet, (2) carbon current collector, (3) disposable immuno-column, (4) highly dispersed antibody-modified carbon particles (immunosorbent), (5) carbon counter electrode, (6) AglAgCl reference electrode and (7) fluid outlet. (Reprinted from [16] with permission from Elsevier.)... 

Pressure-balanced AglAgCl reference electrodes have been extensively used for corrosion monitoring in boiling water reactor environment [41]. The potential of the thermoelectrochemical cell AglAgCl versus the standard hydrogen electrode at temperature, T, was expressed as a sum of the isothermal potential and thermal liquid-junction potential. 

Fig. 7.5 AglAgCl reference electrode schematic for chlraide baths...

An alternate reference system to that of the H2 electrode is the AglAgCl reference electrode. Due to the difference in solvation ability of PlLs compared to ILs, the dissolution of halide salts such as KCl is far more readily accomplished. As such some researchers have constructed AglAgClIKCl (saturated in PlLs) reference electrode systems [92,93]. This reference electrode exhibits a very stable potential of 0.216 V vs. SHE [92, 93]. Experimentally the reference electrode is constructed by placing a silver wire with a AgCl surface layer into a reference compartment containing a saturated solution of KCl in the PIL of choice. 

As indicated in a previous review (627) comparison of voltametric data on the M(R2Dtc) complexes is difficult for many cases because different solvents and reference electrodes have been used. Major, extensive studies have been reported by two groups. The Nijmegen group have reported studies in CH2C12 versus a saturated calomel electrode (480,602,604,609). The Australian group, on the other hand, reported electrochemical studies in acetone versus a AglAgCl, 0.lAf LiCl electrode (115,116, 309, 311,312, 313). 

For higher temperature applications (up to 1,200 °C), quartz is commonly used, which begins to soften at around 1,400 °C. However, as was seen with the AglAgCl reference for chloride melts employed by Gao et al. [68], the lower temperature use (below 700 °C) was limited due to the high impedance ( 4 x 10 Q) of the reference electrode. The thickness of the end-wall is such that insufficient ionic conduction at temperatures below 750 °C is common. The majority of potentiostats... 

The electrochemical cell itself consisted of essentially a flat cell, fixed inside in the optimal position within the EPR cavity so as to ensure maximum sensitivity. The working electrode employed was either a platinum mesh [102] or later, a partly laminated gold mesh [103, 104], An AglAgCl electrode was used as the reference, whilst two counter electrodes were employed to minimize oscillation of the cell voltage. The first counter electrode, a palladium sheet, is situated below the flat part of the cell, whilst the second, connected by a resistor to the potentiostat, is located above it. 

Polarization curves were recorded in a three-compartment standard electrochemical cell at the room temperature. The sweep rate was 1 mV s and current interrupt was applied at each 0.5 s. The platinum foil counter electrode and the reference—saturated silver/silver chloride, AglAgCl—electrode were placed in separate compartments. The working electrode was glassy carbon disc (d = 03 cm) placed parallel to the counter electrode. 

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