GENERAL-MODELS FOR SURFACE NUCLEATION AND 3-DIMENSIONAL GROWTH - THE EFFECTS OF CONCURRENT REDOX REACTIONS AND OF DIFFUSION

The formulation of potentiostatic current-time transients for the electrocrystallization of deposits under charge-transfer control is derived for two general models (spherical caps and hemispheroids). The shape of the whole transient (up to the steady state) is derived, and it is shown that the rate of electrocrystallization is not necessarily controlled by the total deposit surface area. The effects of concurrent redox reactions and the role of diffusion through the solution are considered. It is shown that the latter phenomena can be discussed in terms of generalized differential equations which take account of changes due to the overlap of diffusion zones.