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Determination of Critical Conditions for the Formation of Electrodeposited Copper Structures Suitable for Electrodes in Electrochemical Devices

View Article: PubMed Central

ABSTRACT

Electrodeposition of copper from acid sulfate solutions at overpotentials on the plateau of the limiting diffusion current density and at higher overpotentials was examined. The average current efficiencies for hydrogen evolution reaction are determined by a measurement of the quantity of evolved hydrogen and the overall electrodeposition current as a function of electrodeposition time, while morphologies of copper deposits are examined by the use of the scanning electron microscopy (SEM) technique. It is found that the open and porous structures of copper deposits (denoted and as honeycomb – like copper structures), suitable for electrodes in electrochemical devices such as fuel cells and chemical sensors, were reached by electrodeposition processes from solutions with the lower concentrations of Cu (II) ions (0.15 M CuSO4 and less in 0.50 M H2SO4) at overpotentials outside the plateau of the limiting diffusion current density at which the quantity of evolved hydrogen was enough to change hydrodynamic conditions in the near – electrode layer. The main characteristics of these copper structures were craters or holes formed primarily due to the attachment hydrogen bubbles with agglomerates of copper grains between them.

No MeSH data available.


Copper deposits obtained at overpotential of 650 mV. Quantity of electricity: 10.0 mAhcm-2. (a) and (b): solution (I). Magnification: (a) × 750, (b) × 2000; (c) and (d): solution (II). Magnification: (c) × 2000, (d) × 750; (e) and (f): solution (III). Magnification: (e) × 750, (f) × 2000.
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f6-sensors-07-00001: Copper deposits obtained at overpotential of 650 mV. Quantity of electricity: 10.0 mAhcm-2. (a) and (b): solution (I). Magnification: (a) × 750, (b) × 2000; (c) and (d): solution (II). Magnification: (c) × 2000, (d) × 750; (e) and (f): solution (III). Magnification: (e) × 750, (f) × 2000.

Mentions: Copper dendrites are formed from all three solutions during electrodeposition processes at an overpotential of 650 mV with a quantity of electricity of 10.0 mAhcm−2. However, from Figure 6 it can be seen that the shape of copper dendrites depends strongly on the concentration of Cu(II) ions. Very branchy copper dendrites consisting of corncob–like elements were formed from solution (I) (Figures 6a and b). Copper dendrites formed from solution (II) presented a mixture of very branchy dendritic forms (Figure 6c) and those shaped like flowers (Figure 6d). Finally, the copper deposits obtained from solution (III) presented a mixture of flower–like (Figure 6e) and corncob–like forms (Figure 6f).


Determination of Critical Conditions for the Formation of Electrodeposited Copper Structures Suitable for Electrodes in Electrochemical Devices
Copper deposits obtained at overpotential of 650 mV. Quantity of electricity: 10.0 mAhcm-2. (a) and (b): solution (I). Magnification: (a) × 750, (b) × 2000; (c) and (d): solution (II). Magnification: (c) × 2000, (d) × 750; (e) and (f): solution (III). Magnification: (e) × 750, (f) × 2000.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756708&req=5

f6-sensors-07-00001: Copper deposits obtained at overpotential of 650 mV. Quantity of electricity: 10.0 mAhcm-2. (a) and (b): solution (I). Magnification: (a) × 750, (b) × 2000; (c) and (d): solution (II). Magnification: (c) × 2000, (d) × 750; (e) and (f): solution (III). Magnification: (e) × 750, (f) × 2000.
Mentions: Copper dendrites are formed from all three solutions during electrodeposition processes at an overpotential of 650 mV with a quantity of electricity of 10.0 mAhcm−2. However, from Figure 6 it can be seen that the shape of copper dendrites depends strongly on the concentration of Cu(II) ions. Very branchy copper dendrites consisting of corncob–like elements were formed from solution (I) (Figures 6a and b). Copper dendrites formed from solution (II) presented a mixture of very branchy dendritic forms (Figure 6c) and those shaped like flowers (Figure 6d). Finally, the copper deposits obtained from solution (III) presented a mixture of flower–like (Figure 6e) and corncob–like forms (Figure 6f).

View Article: PubMed Central

ABSTRACT

Electrodeposition of copper from acid sulfate solutions at overpotentials on the plateau of the limiting diffusion current density and at higher overpotentials was examined. The average current efficiencies for hydrogen evolution reaction are determined by a measurement of the quantity of evolved hydrogen and the overall electrodeposition current as a function of electrodeposition time, while morphologies of copper deposits are examined by the use of the scanning electron microscopy (SEM) technique. It is found that the open and porous structures of copper deposits (denoted and as honeycomb – like copper structures), suitable for electrodes in electrochemical devices such as fuel cells and chemical sensors, were reached by electrodeposition processes from solutions with the lower concentrations of Cu (II) ions (0.15 M CuSO4 and less in 0.50 M H2SO4) at overpotentials outside the plateau of the limiting diffusion current density at which the quantity of evolved hydrogen was enough to change hydrodynamic conditions in the near – electrode layer. The main characteristics of these copper structures were craters or holes formed primarily due to the attachment hydrogen bubbles with agglomerates of copper grains between them.

No MeSH data available.