Rotating ring-hemisphere electrode

Fig. 9. Types of rotating spherical electrodes reported in the literature, (a) Rotating micro-sphere electrode, (b, c) rotating hemisphere electodes (d) rotating ring-hemisphere electrodes (e) rotating dropping mercury electrode.

The hemispherical electrode may be coupled with a ring [20] to form a rotating ring-hemisphere electrode (RRHSE) as shown as Fig. 9(d). The ability of this combination to detect intermediate reaction products is demonstrated in Fig. 10, where a series of cathodic sweep curves for the reduction of Cu2 + in acidic cupric chloride solution are... 

The rotating ring-hemisphere electrode has been used by Chin [21] to study the dissolution of iron in neutral sulfate solutions, and by Zou and Chin [61, 62] to identify the corrosion products of iron in concentrated sodium hydroxide solutions. 

The experimental setup of a rotating hemispherical electrode (RHSE) is similar to that of a rotating disk electrode [50]. The basic system consists of a removable hemispherical electrode, and a variable speed rotator equipped with a provision, such as the slip-ring contact, to make electric connection to the hemispherical electrode during the experiments. 

In this section, we consider mass transport-controlled currents to disc and concentric ring electrodes on a planar spinning disc surface. For other less common rotating electrodes, e.g. rotating hemisphere, see Table 3. 

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