The specific surface of electrodeposited copper was determined using recently proposed way for the estimation of the real surface area of metal deposits. The obtained values of the specific surface of copper deposits were correlated with the corresponding morphologies of copper deposits.Specifična površina elektrohemijski istaloženog taloga bakra je bila određena korišćenjem nedavno predloženim načinom za procenu realne površine taloga metala. Dobijene vrednosti specifične površine taloga bakra su bile povezane sa odgovarajućim morfologijama taloga bakra

Nikolić, Nebojša D.

Pavlović, Lj.J.

Pavlović, Miomir

Popov, Konstantin I.

Zastita materijala

English

 CER - Central Repository of the Institute of Chemistry;  Technology and Metallurgy

N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 3
N. D. NIKOLIĆ, K. I. POPOV, Scientific paper 
LJ. J. PAVLOVIĆ, M. G. PAVLOVIĆ UDC:669.337.142:620.179.11.191.3/.4=20 
New method of the determination of specific surface 
of copper obtained by the electrodeposition 
 
The specific surface of electrodeposited copper was determined using recently proposed way 
for the estimation of the real surface area of metal deposits. The obtained values of the 
specific surface of copper deposits were correlated with the corresponding morphologies of 
copper deposits. 
Key words: electrodeposition; copper; specific surface of copper deposit. 
 
1. INTRODUCTION 
The specific surface of the electrodeposited 
metal, Ssp, is given by Eq. (1): 
m
S
S sp  (1) 
where S represents the surface area of a deposit 
and m, mass of a metal obtained by 
electrodeposition process. 
The mass of electrodeposited metal, m can be 
easily calculated using Faraday`s law. According 
to Faraday`s law, mass of the electrodeposited 
metal, m, is given by Eq. (2): 
M
Fn
dη
e
0
I 

t
tI
m  (2) 
where ne is the number of electrones involved 
in the metal deposition reaction, M is the atomic 
mass of the deposited metal, F is the Faraday 
constant, I current efficiency of the electro-
deposited metal and 
t
tI
0
d  is the quantity of passed 
electricity. 
On the other hand, the determination of real 
surface area of metal electrodeposits can represent 
problem because there is no unique and corres-
ponding technique which would enable it. The real  
   
Address authors: ICTM – Institute of 
Electrochemistry, University of Belgrade, Njegoševa 
12, 11 000 Belgrade, Serbia 
surface of some metal deposits can be determined 
by the STM and AFM techniques (using the option 
surface area diff., in the accompanying software 
package) but the application of these techniques is 
only suitable for compact and relatively smooth 
deposits. In order to solve this problem in situ, the 
new and relatively easy way for the estimation of 
real surface area has been developed recently in 
our research group [1, 2]. This method is based on 
the measurement of currents before and after 
electrodeposition at the corresponding overpoten-
tial and it will be presented later in Experimental. 
The determination of real surface of disperse 
deposits is especially difficult owing to very high 
and developed surface area of this deposit type. 
For that reason, the aim of this work will be to 
estimate the possibility of determination of the 
specific surface of the electrodeposited metal by 
the use of this new method for the estimation of 
real surface area of metal deposits by measuring 
the active part of it. The obtained values of the 
specific surface will be correlated with the 
corresponding morphologies of metal deposits. 
2. EXPERIMENTAL 
Copper was potentiostatically deposited from 
0.15 M CuSO4 in 0.50 M H2SO4, in an open cell, 
and at a room temperature of (18.0  1.0)oC. 
Doubly distilled water and analytical grade 
chemicals were used for the preparation of the 
solution for electrodeposition of copper. Reference 
and counter electrodes were of a pure copper. The 
electrodepositions of copper were performed at 
overpotentials of 550, 700, 800 and 1000 mV, with 
different quantities of the electricity. 
The electrodeposition processes and the 
determination of the real surface area of metal 
N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 4
deposits were performed using experimental 
procedure described in Refs. [1, 2] in the following 
way: copper substrates (S0) are covered with a thin 
copper film by electrodeposition at an over-
potential of 300 mV during 2 min. After a re-
laxation of the diffusion layer for 15 min, the 
current at overpotential of 50 mV, I0, is recorded, 
being proportional to the original electrode surface 
area S0. The overpotential is then adjusted to the 
desired value and deposition is carried out. After 
the determined quantity of electricity had been 
reached, the overpotential is decreased to 50 mV 
and after relaxation of the diffusion layer for 15 
min, the current, I, corresponding to the surface S 
generated during electrodeposition, is determined. 
The surface area of the deposit is then calculated 
using the equation (3). 






 1
0
η
00
0
η
0 I
I
SS
I
I
SS  (3) 
Copper deposits were examined by the 
scanning electron microscope (SEM) – model 
JOEL T20. 
3. RESULTS AND DISCUSSION 
The overpotentials of 550 and 700 mV be-
longing to the plateau of the limiting diffusion 
current density, while the overpotentials of 800 and 
1000 mV were for 50 and 250 mV outside the 
plateau of the limiting diffusion current density [3]. 
According to Eqs. (1) – (3), the specific surface 
of the electrodeposited metal, Ssp, can be given by 
Eq. (4): 
















1
d
1
Mη
Fn
M
Fn
dη
1
0
η
0
I
0e
e
0
I
0
η
0
sp I
I
tI
S
tI
I
I
S
S
tt
 (4) 
In this case, the number of electrones involved 
in the electrodeposition reaction, ne is 2, the atomic 
mass of copper (M) is 63.54 g/mol and Faraday 
constant, F, is 96485 As/mol. In this investigation, 
the original electrode surface before electro-
deposition, S0, was 0.50 cm
2. 
The current efficiencies for the copper 
electrodeposition at overpotentials of 550, 700, 800 
and 1000 mV are experimentally determined using 
procedure for the measurement of the hydrogen 
evolution described in Ref. 3. At the over-
potential of 550 mV, the current efficiency for the 
copper electrodeposition was 100 % [3]. The cu-
rrent efficiency for the copper electrodeposition at 
the overpotential of 700 mV was  98.0 % [3]. At 
overpotentials of 800 and 1000 mV, the hydrogen 
evolution takes place, and consequently, current 
efficiencies for the copper electrodeposition are 
considerably smaller than those observed at lower 
overpotentials. At the overpotential of 800 mV, the 
current efficiency for the copper electrodeposition 
was 89.2 %, while at the overpotential of 1000 
mV, this value reached up to a value of 70.0 % [3]. 
Current I and I0 are obtained in the way 
described above. 
The estimated values of the specific surface of 
the electrodeposited copper in the way described 
above are given in Tables (1) – (4) in APENDIX I. 
The dependence of the specific surface of the 
electrodeposited copper on the quantity of the 
electricity is given in Fig. 1. Two groups of the 
dependences of the specific surface of the 
electrodeposited copper on the quantity of the 
electricity can be observed from this Figure. 
0 5 10 15 20 25 30 35 40
0
400
800
1200
1600
2000  550 mV
 700 mV
 800 mV
 1000 mV
S s
p/
 c
m
2 g
-1
I.t/ As  
Fig. 1. The dependence of the specific surface of 
the electrodeposited copper on the quantity of the 
electricity. 
The first one is observed for overpotentials of 
550 and 700 mV at which the hydrogen evolution 
does not exist (550 mV) or it is very small (700 
mV). The characteristic of this group is maximum 
of the specific surface which is a function of the 
quantity of the electricity. The increase of the 
overpotential led to the decrease of the quantity of 
the electricity needed to reach maximum of the 
specific surface. 
The analysis of SEM microphotographs of 
copper deposits obtained at these overpotentials 
showed that maximum values of the specific 
N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 5
surface correspond to the formation of cauliflower 
structures. Figure 2 shows the copper deposit 
obtained at the overpotential of 550 mV with the 
quantity of the electricity of 18.0 As (Fig. 2a) and 
the copper deposit obtained at the overpotential of 
700 mV with the quantity of the electricity of 4.5 
As (Fig. 2b). 
The decrease of the specific surface with the 
increase of the quantity of the electrodeposited 
copper is accompanied by the formation of 
dendritic forms. Figure 3 shows the copper deposit 
obtained at the overpotential of 550 mV with the 
quantity of the electricity of 36.0 As, and can be 
seen from this Figure that the formed copper 
dendrites are relatively alone (Fig. 3a) and this 
deposit represents a mixture of cauliflower and 
dendritic forms (Fig. 3b). 
    a) 
    b) 
Fig. 2. Copper deposits obtained at the overpotential 
of: a) 550 mV; the quantity of the electricity: 18.0 As, 
b) 700 mV; the quantity of the electricity: 4.5 As 
On the other hand, copper deposits obtained at 
the overpotential of 700 mV with quantities of the 
electricity larger of 4.5 As showed purely dendritic 
forms (Fig. 4). Copper dendrites were consisted of 
corncob – like elements, and the whole electrode 
surfaces were covered with dendritic forms after 
the electrodeposition with quantities of the elec-
tricity larger of approximately 10.0 As. 
Anyway, the values of Ssp obtained at 700 mV 
before initiation of the dendritic growth, i.e. with 
low quantities of the passed electricity, are similar 
to those obtained at 550 mV but with larger quan-
tities of the electricity. Besides, the farther increase 
of Ssp with the increasing quantity of the electricity 
before dendritic growth initiation is because of the 
decrease of size of deposit grains. After formation 
of precursors of dendrites and dendrites the Ssp 
strongly increases and remains approximately 
constant up to quantity of electricity at which the 
overlap of dendrites begins. At larger quantities of 
electricity the Ssp value decreases up to constant 
value, which probably corresponds to the esta-
blished front of dendritic deposit growing to the 
bulk of the solution. 
    a) 
    b) 
Fig. 3. The copper deposit obtained at the 
overpotential of 550 mV with the quantity of the 
electricity of 36.0 As: a) x 2000, b) x 750. 
The second group of the dependences of the 
specific surface of the electrodeposited copper on 
the quantity of the electricity is obtained for the 
overpotentials of 800 and 1000 mV. As mentioned 
above, the hydrogen evolution takes place during 
the electrodeposition at these overpotentials. It can 
be seen from Fig. 1 that there is not maximum the 
specific surface in a function of the quantity of the 
electrodeposited metal. The specific surface of the 
electrodeposited copper decreased with the incre-
ase of the quantity of the electricity. This is due to 
the overlap of the agglomerates of grains in pro-
longed electrodeposition. At low deposition times 
N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 6
Ssp is very large. Also, it can be observed from Fig. 
1 that there is not essential difference between the 
specific surfaces obtained at the overpotential of 
800 mV and ones obtained at 1000 mV. SEM 
analysis of copper deposits obtained at these over-
potentials showed that copper deposits were a very 
porous, with large craters or holes formed of the 
attachment of the hydrogen bubbles (these copper 
structures can be denoted as “honeycomb” structu-
res ). The typical copper deposits obtained at 
overpotentials of 800 and 1000 mV are shown in 
Fig. 5. From this Figure can be noticed that 
morphologies of these copper deposits consisted of 
copper grains grouped in small aggregates. Hove-
wer, copper dendrites are not formed during elec-
trodepositions at these overpotentials. 
    a) 
    b) 
    c) 
Fig. 4. Copper deposits obtained at the overpotential 
of 700 mV. The quantity of the electricity: a) 9.0 As, 
b) 18.0 As, c) 36.0 As. 
Figure 6 shows the dependence of the specific 
surface of the electrodeposited copper on the 
overpotential of the copper electrodeposition for 
different quantities of the electricity. It can be seen 
from this Figure the existance of maximum of the 
specific surface of the electrodeposited copper at 
the overpotential of 700 mV for all examined 
quantities of the electricity except for the quantity 
of the electricity of 4.5 As. Hence, according to 
this method, dendritic deposits showed to have the 
largest electrode surface area. 
    a) 
    b) 
Fig. 5. Copper deposits obtained with the quantity 
of the electricity of 36.0 As and at the overpotential 
of: a) 800 mV, b) 1000 mV. Magnification: x 2000. 
The decrease of the specific surface with the 
increase of overpotentials of the electrodeposition 
from 700 to 800 mV can be explained by the 
change of the hydrodynamic conditions in the near 
electrode layer by the evolved hydrogen. The range 
of overpotentials between 700 and 800 mV 
represents transient region of overpotentials when 
the hydrogen evolution becomes an enough 
intensive to effect on the electrodeposition process, 
i.e to change hydrodynamic conditions in the near 
electrode layer. Then, the electrodeposition takes 
place at overpotential which is effectively lower 
than the specified one and, for that reason, copper 
morphologies obtained at overpotentials of 800 and 
1000 mV are similar to ones obtained at lower 
N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 7
overpotentials before the initiation of dendritic 
growth . 
600 700 800 900 1000
0
200
400
600
800
1000
1200
 4.5 As
 9.0 As
 18.0 As
 27.0 As
 36.0 As
S s
p/ 
cm
2 g
-1
/ mV  
Fig. 6. The dependence of the specific surface of 
the electrodeposited copper on the overpotential of 
the copper electrodeposition. 
The absence of maximum of the specific sur-
face of the electrodeposited copper for deposits 
obtained with the quantity of the electricity of 4.5 
As can be explained by the absence of the forma-
tion of dendritic forms for the copper deposit obta-
ined at the overpotential of 700 mV with this qua-
ntity of the electricity. Copper deposits obtained 
with this quantity of the electricity were relatively 
similar each others (no dendritic growth!). 
Also, it is necessary to note again that copper 
dendrites formed during electrodepositions at 
overpotentials of 550 mV and 700 mV with the 
quantity of the electricity of 36.0 As were 
completely different. As mentioned earlier, copper 
dendrites formed at 550 mV were relatively alone, 
and this deposit represented the mixture of 
cauliflower like and dendritic forms (Fig. 3). On 
the other hand, the copper deposit obtained at 700 
mV was much ramified dendritic structure (Fig. 4). 
This clear difference is confirmed and by the 
different measured specific surfaces of these 
copper deposits. 
Finally, it was shown by the proposed method 
that dendritic copper deposits had the largest 
electrode surafce area, i.e. these deposits are with 
maximum of the specific surface. This is consistent 
with that shown in Ref. 4, where Chassaing et all. 
showed by impedance spectroscopy that the 
electrodeposition of ramified deposits is related to 
the large increase of the deposit surface area. In 
this stage, this agreement makes the proposed 
method to be very relevant for the estimation of 
specific surface of electrodeposited metal. 
Acknowledgement: The work was supported 
by the Ministry of Science and Environmental 
Protection of the Republic of Serbia under the 
research project: “Deposition of ultrafine powders 
of metals and alloys and nanostructured surfaces 
by electrochemical techniques” (No. 142032G). 
 
REFERENCE 
[1] Popov, K. I., Nikolić, N. D., Rakočević, Z., 
J.Serb.Chem.Soc., 67 (2002) 635. 
[2] Popov, K. I., Nikolić, N. D., Rakočević, Z., 
J.Serb.Chem.Soc., 67 (2002) 769. 
[3] Nikolić, N. D., Popov, K. I., Pavlović, Lj. J., 
Pavlović, M. G., J.Electroanal.Chem., 588 
(2006) 88. 
[4] Chassaing, E., Rosso, M., Sapoval, B., 
Chazalviel, J. – N., Electrochim. Acta, 38 
(1993) 1941. 
APENDIX I 
The values of the specific surface of the electrodeposited copper obtained at overpotentials of 550, 
700, 800 and 1000 mV with different quantities of the electricity 
Table 1 - The estimated values of the specific surface of the electrodeposited copper obtained at the 
overpotential of 550 mV 
 Quantity of the electricity/ As I0/ mA I/ mA Ssp/cm
2 g-1 
1. 4.5 1.60 2.10 92.19 
2. 9.0 1.50 3.20 166.20 
3. 18.0 1.00 4.50 251.07 
4. 27.0 0.90 3.70 152.44 
5. 36.0 0.90 4.80 152.29 
N. D. NIKOLIĆ et all ... NEW METHOD OF THE DETERMINATION OF SPECIFIC … 
ZAŠTITA MATERIJALA 48 (2007) broj 1 8
Table 2 - The estimated values of  the specific surface of the electrodeposited copper obtained at the 
overpotential of 700 mV 
 Quantity of the electricity/ As I0/ mA I/ mA Ssp/cm
2 g-1 
1. 0.42 0.76 0.78 93.20 
2. 0.90 0.78 0.90 258.42 
3. 1.45 0.84 1.35 631.53 
4. 2.80 0.90 2.80 1139.31 
5. 4.50 0.96 4.00 1091.08 
6. 6.30 0.87 4.60 1057.06 
7. 9.0 0.72 4.95 1010.58 
8. 18.0 0.84 7.90 719.65 
9. 27.0 0.80 7.40 472.04 
10. 36.0 0.80 9.60 473.03 
Table 3 - The estimated values of the specific surface of the electrodeposited copper obtained at the 
overpotential of 800 mV 
 Quantity of the electricity/ As I0/ mA I/ mA Ssp/cm
2 g-1 
1. 1.16 1.25 3.00 1991.76 
2. 1.40 1.05 2.70 1870.84 
3. 2.80 1.18 4.10 1507.96 
4. 4.50 1.20 4.60 1059.05 
5. 9.0 1.35 4.60 449.06 
6. 18.0 1.45 5.80 283.25 
7. 27.0 1.30 6.90 270.44 
8. 36.0 1.10 7.00 250.84 
Table 4 - The estimated values of the specific surface of the electrodeposited copper obtained at the 
overpotential of 1000 mV 
 Quantity of the electricity/ As I0/ mA I/ mA Ssp/cm
2 g-1 
1. 4.5 1.25 4.00 1073.70 
2. 9.0 1.28 4.20 553.04 
3. 18.0 1.35 5.40 359.96 
4. 27.0 1.35 6.20 287.41 
5. 36.0 1.25 5.85 221.53 
 
REZIME 
NOVI METOD ODREĐIVANJA SPECIFIČNE POVRŠINE ELEKTROHEMIJSKI 
ISTALOŽENOG BAKRA 
Specifična površina elektrohemijski istaloženog taloga bakra je bila određena korišćenjem 
nedavno predloženim načinom za procenu realne površine taloga metala. Dobijene vrednosti 
specifične površine taloga bakra su bile povezane sa odgovarajućim morfologijama taloga 
bakra. 
Ključne reči: elektrohemijsko taloženje; bakar; specifična površina taloga bakra 


Novi metod određivanja specifične površine elektrohemijski istaloženog bakra

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Novi metod određivanja specifične površine elektrohemijski istaloženog bakra

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