Optimization of electrolytic process of formation of open and porous copper electrodes by the pulsating current (PC) regime

Abstract

Optimization of process of formation of open and porous copper electrodes, denoted as the honeycomb-like ones, by the regime of pulsating current (PC) is considered. The square-waves PC were consisted of the same amplitude current density and pause duration of 10 ms, while the analyzed deposition pulses were: 1, 4, 7, 10 and 20 ms. Morphologies of electrodeposited copper and the quantities of evolved hydrogen during electrodeposition processes were compared with the surface morphology and the quantity of evolved hydrogen obtained by copper electrodeposition in the galvanostatic mode. In galvanostatic mode, electrodeposition of copper was performed at a current density which corresponded to the amplitude current density in the PC regimes. Honeycomb-like deposits were formed at the constant current density and by the PC regimes with deposition pulses of 7, 10 and 20 ms. The mixture of holes constructing the honeycomb-like structure and dish-like holes was obtained with a deposition pulse of 4 ms. Finally, dish-like holes were only formed with a deposition pulse of 1 ms. The change of the shape of holes was discussed by the change of hydrodynamic conditions in the near-electrode layer caused by evolved hydrogen. The specific energy consumption in the PC regimes of electrolysis was also discussed. Analysis of the specific energy consumption showed that energy saving of about 15% can be attained in the production of honeycomb-like electrodes by the choice of the appropriate PC regime.