Electroless deposition interfering reactions

Fig. 2. Current-potential curves in Evans diagram [29] format for reduction of Cu2+ ions and oxidation of H2CO. and are the equilibrium, or open circuit, potentials for the Cu2+ reduction and H2CO oxidation reactions, respectively. Assuming negligible interfering reactions, the vertical dashed lines indicate the exchange current densities for the two half reactions, and the deposition current for the complete electroless solution. Adapted from ref. 23.

Electroless Deposition in the Presence of Interfering Reactions. According to the mixed-potential theory, the total current density, is a result of simple addition of current densities of the two partial reactions, 4 and However, in the presence of interfering (or side) reactions, 4 and/or may be composed of two or more components themselves, and verification of the mixed-potential theory in this case would involve superposition of current-potential curves for the electroless process investigated with those of the interfering reactions in order to correctly interpret the total i-E curve. Two important examples are discussed here. 

The second example is electroless deposition of copper from solutions containing dissolved oxygen (49,53). In this case the interfering reaction is the reduction of the oxygen, and the cathodic partial current density is the sum of two components ... 

Conclusions. The discussion in this section shows the validity of the mixed-potential theory for electroless deposition of Cu, Ni, and An. The discussions in the sections Electroless Deposition in the Presence of Interfering Reactions and Interaction Between Partial Reactions illustrate the complexities of electroless processes and the presence of a variety of factors that should be taken into account when applying the mixed-potential theory to the electroless processes. 

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See also in sourсe #XX -- [ ]

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