Electrode semi-immersed

The electrolysis of the studied systems was carried out in the same cell as voltammetry measurements under the mode of either constant current or voltage. In the constant current mode, the applied current density was in the range of 0.01 0.2 A/ sm2 with reference to the surface area of the cathode before starting the electrolysis. Semi-immersed glassy carbon plate electrodes (cathode area - 5 sm2, anode area - 10 sm2) were used while electrolysis experiments. A powder product was either settled down onto the crucible bottom or assembled on the cathode in the view of electrolytic pear . The deposit was separated from salts by successive leaching with hot water. Thereafter, the precipitate was washed with distilled water by decantation method several times and dried to a constant mass at 100 - 150 °C. The electrolysis products were analyzed by chemical and X-ray phase analyses, methods of electron diffraction and electronic microscopy (transmission and scanning). 

Figure 3-1 shows an example of a voltaic cell. A zinc electrode is immersed in a solution of NaCl and a copper electrode in a solution of CuCl2,with a semi-permeable membrane separating the two solutions. If a wire connects the two electrodes, electrons flow spontaneously from the zinc electrode to the copper electrode because is a stronger oxidising agent than Zn(s). At the copper cathode, Cu in the solution is reduced to CU(s) by electrons that are the product of the simultaneous oxidation of Zn(s) to Zn at the zinc anode. The difference in oxidation potential of the two metals results in a differential of approximately 1.10 volts between the two electrodes (assuming equal concentrations of Cu and Zn ). Across the membrane, Cf ions must move toward or... 

Consider an inert metal with a fractal electrode immersed into an electrolyte containing a redox couple. We assume semi-infinite diffusion of the oxidized species Ox and the reduced species Red in the electrolyte. For the sake of simplicity we assume that the solution contains initially (at the time, t = 0) only the oxidized form and the bulk and surface concentrations are identical, i.e., cox=cL- The electrode is initially subjected to an electrode potential where no reaction takes place. The only reaction occurring when the potential is lowered, is the reversible reduction of Ox to Red, i.e., Ox + ze = Red. In addition, it is assumed that the overall reaction is limited by diffusion of Ox in electrolyte. 

In passing, we should also mention one additional microstructural factor potentially impacting the overall electrode performance constriction of the ionic current in the electrolyte near the electrode/electrolyte interface. To better understand this effect, consider a circular disk electrode of diameter d immersed in a semi-infinite electrolyte of conductivity... 

The experiments were carried out in a semi-batch stirred reactor with continuous oxygen feed. The reactor is a one liter Pyrex flask with flattened bottom and baffles which is fitted with five standard 24/40 necks to accomodate the gas inlet, gas vent, sampling tube, and pH electrode. The reactor is immersed in a standard water bath for temperature control. Gas is fed at a flow rate of 3.0 + 0.1 1/min through a rotameter. The solution is stirred at 1620 rpm. 

If the copper was immersed in a sodium chloride solution with or without benzo-hydroxamic acid (BHA) derivatives, a thick layer was formed on the metal surface, which consisted of copper oxide, chloride, and the inhibitor molecule. The results revealed that the curve representing the aggressive solution showed two semi-circles which characterize the anodic reaction involving mass transfer through the copper oxide layer. The semi-circle at a higher frequency is due to the modulation for cop-per(I)chloride adsorbed at the electrode, while the low frequency part represents the diffusion process at the electrode due... 

This class of reference electrode consists of an inert conducting or semi-conducting material immersed in an IL solution containing a redox couple ... 

---