Abstract
An equation for the diffusional flux in the laminar flow at the plate electrode, in which the electrode reaction takes place only on a portion of the surface of the plate, was derived theoretically on the basis of the hydrodynamic conceptions developed by Levich . Applying the theoretical treatment of Levich to the platinum plate convection electrode (PPCE), the equation of the limiting current is obtained as follows:
iι=0.355nFAc0D2/3υ1/2ν-1/6{(1+x1/a)3/4-(x1/a)3/4}-2/3
In the case that a/x1« the limiting current is given by iι=0.355nFAc0D2/3υ1/2ν-1/6a-1/3x1-1/6
Using a 2 x 10-4M hexacyanoferrate (II) solution, the experimental confirmation for the theoretical equation mentioned above was carried out. The results indicated that the limiting current at PPCE obeyed the equation. This shows that the velocity of the fluid flow is proportional to the tangential velocity of the rotating disk, that is, the value of the proportional constant is 0.40, which is the same value obtained in the previous work.
