Potential transients on a renewed electrode as a source of information on the surface concentration of catalytically active adatoms

Abstract

Potential transients on renewable gold and silver electrodes in cyanide solutions containing catalytically active ions of lead and thallium are measured. The transients are recorded both on freshly renewed electrodes and on renewed electrodes kept in solution for specified time periods ∆ t . The behavior of transients following a change in the concentration of lead and thallium ions, current density, and ∆ t qualitatively conforms to regularities that could be expected if the catalytically active adatoms were inserted into the deposit similarly to the admixtures. Methods for determining coefficients of capture of such adatoms by the growing metal deposit are suggested. Factors that hamper determination of these coefficients and make it worthwhile to select a method for their determination that would use potential transients are considered. The capture coefficient for the incorporation of lead adatoms in the growing silver deposit is nearly 20 times that for gold.

Additives for Superconformal Gold Feature Filling

“…Similar effects have been reported for chronopotentiometric experiments. 17,18 Absent additives, deposition remains minimal almost to the −1.3 V switching potential in the associated voltammetry, shown in the same figure, and hysteresis is modest and due to roughening at the most negative potentials. The addition of Pb 2+ increases deposition currents on the negative-going scan, with further increase on the return scan yielding hysteresis in the cyclic voltammograms.…”