Nucleation and Growth of New Phases on Electrode Surfaces

Nucleation, as the onset of a first-order phase transition, is common ground between several disciplines. The formation of short-range ordered aggregates in a melt or solution in polymer science [1], molecular assemblies in biological systems, the condensation of vapors to form mist in the atmosphere, or cavitation phenomena in fluid mechanics [2], all take place through the creation of small aggregates of the condensed phase out of the parent phase. 

The classical nucleation theory, based on Gibbs thermodynamics statements, uses the macroscopic properties characteristic of bulk phases, such as free energies and surface tensions, for the description of small clusters. Contradictory results arose in early studies of electrochemical nucleation [9], where the size of a critical mercury nucleus on a platinum substrate amounted to only a few atoms, with properties that could substantially differ 

Developments in Electrochemistry Science Inspired by Martin Fleischmarm, First Edition. Edited by Derek Fletcher, Zhong-Qun Xian and David E. Williams. 

1 An Overview of Martin Fleischmann s Contributions to Electrochemical Nucleation Studies 

Studies on the behavior of the lead dioxide electrode [21], the oxidation of silver sulfate to silver oxide [22], the kinetics of electrocrystallization of thin films of calomel [23] and the electrodeposition of nickel [24], as well as the concepts and applications of micrometer-sized electrodes [25], stand as pioneering research concerning nudeation and growth problems. Wisely designed experimental procedures combined with mathematical models recognizing the chemical nature of the problem led to many new insights. 

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