The effects of copper ion concentrations and electrolyte temperature on the
morphologies and on the apparent densities of electrolytic copper powders at
high current densities under galvanostatic regime were examined. These
parameters were evaluated by the current efficiency of hydrogen evolution. In
addition, scanning electron microscopy was used for analyzing the morphology
of the copper powders. It was found that the morphology was dependent over
the copper ion concentration and electrolyte temperature under same current
density (CD) conditions. At 150 mA cm-2 and the potential of 1000?20 mV (vs.
SCE), porous and disperse copper powders were obtained at low concentrations
of Cu ions (0.120 M Cu2+ in 0.50 M H2SO4). Under this condition, high rate of
hydrogen evolution reaction took place parallel to copper electrodeposition.
The morphology was changed from porous, disperse and cauliflower-like to
coral-like, shrub-like and stalk-stock like morphology with the increasing of
Cu ion concentrations towards 0.120 M, 0.155 M, 0.315 M, 0.475 M and 0.630 M
Cu2+ in 0.5 M H2SO4 respectively at the same CD. Similarly, as the
temperature was increased, powder morphology and apparent density were
observed to be changed. The apparent density values of copper powders were
found to be suitable for many of the powder metallurgy applications.
Facile Fabrication of Robust Hydrogen Evolution Electrodes under High Current Densities via Pt@Cu Interactions
