The effect of hydrogen codeposition on the morphology of copper electrodeposits. 1. The concept of effective overpotential

The effect of hydrogen codeposition on the morphology of copper electrodeposits was studied. The dependences of the overall current and the volume of evolved hydrogen on the quantity of electricity used were plotted and the average current efficiencies of the evolved hydrogen were derived from them. The morphologies of copper electrodeposits were correlated with the hydrogen evolution rates. It was shown that dendrites are the main characteristic of deposits obtained at overpotentials belonging to the limiting diffusion current density plateau, at which the hydrogen evolution rate is low. At larger overpotentials the dominant form become craters in the honeycomb-like electrodeposits due to the intensive hydrogen codeposition. (c) 2005 Elsevier B.V. All rights reserved.