Inhibition of Electrocrystallization of a Copper Monoatomic Layer by a Polyacrylamide Additive in an Acid Sulfate Solution

摘要

Peculiarities of an influence of polyacrylamide (PAA) on the charge transfer and crystallization stages during galvanostatic growth of monoatomic layer of copper from an acid sulfate solution were studied. An analysis of the electrode process was based on Vetter's conception of additivity of charge transfer and crystallization overpotentials η_D and η_c. A probable mechanism of an influence of the additive consists in inhibition of growth steps of the deposit by a mixed adsorption layer of HSO_4~- ions and PAA. That layer creates an additional potential barrier to incorporation of copper adatoms into growth sites. Inhibition of the crystallization stage by PAA results in both an increase of η_c and a considerable influence of supersaturation on kinetics of the stage of Cu~(2+) ion reduction.