СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2
Electrocatalytic films based on nanodispersed titanium dioxide modified by Ce(III) were synthesized by sol-gel method and characterized by X-ray diffraction and ultraviolet-visible photocurrent spectra. The average size of nanoparticles was no more thаn 11 nm. The XRD results indicated that TiO2 and...
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| Дата: | 2019 |
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| Мова: | Англійська |
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V.I.Vernadsky Institute of General and Inorganic Chemistry
2019
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| Назва журналу: | Ukrainian Chemistry Journal |
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Репозитарії
Ukrainian Chemistry Journal| _version_ | 1871465368584716288 |
|---|---|
| author | Vorobets , Vera Kolbasov, Gennadii Oblovatna , Svitlana Salamakha, Oleg Karpenko, Sergii Rusetskyi, Ihor |
| author_facet | Vorobets , Vera Kolbasov, Gennadii Oblovatna , Svitlana Salamakha, Oleg Karpenko, Sergii Rusetskyi, Ihor |
| author_institution_txt_mv | [
{
"author": "Vera Vorobets ",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
},
{
"author": "Gennadii Kolbasov",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
},
{
"author": "Svitlana Oblovatna ",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
},
{
"author": "Oleg Salamakha",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
},
{
"author": "Sergii Karpenko",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
},
{
"author": "Ihor Rusetskyi",
"institution": "Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine, Acad. Palladin Ave., 32\/34, 03142, Kyiv, Ukraine"
}
] |
| author_sort | Vorobets , Vera |
| baseUrl_str | https://ucj.org.ua/index.php/journal/oai |
| collection | OJS |
| datestamp_date | 2026-07-22T08:23:41Z |
| description | Electrocatalytic films based on nanodispersed titanium dioxide modified by Ce(III) were synthesized by sol-gel method and characterized by X-ray diffraction and ultraviolet-visible photocurrent spectra. The average size of nanoparticles was no more thаn 11 nm. The XRD results indicated that TiO2 and Ce–TiO2 electrodes with Ce concentrations up to 5 % calcined at 500°C consisted of anatase as the unique phase.  The photocurrent spectra of the Ce–TiO2 electrodes (0 ≤ Ce concentration ≤ 2% mol.)  showed a stronger current in the UV range and a shift in the flat-band potential (Еfb) towards more negative values than that of  TiO2 electrodes. Electrocatalytic properties of TiO2 and Ce–TiO2 electrodes were investigated in the process of oxygen electroreduction. It has been found by I–E curves measurements that the potential of oxygen reduction changes with the film composition. Modifying of TiO2 films by Ce(III)  improves catalytic activity of Ce–TiO2 electrodes ( Ce concentration up to 2% mol.)  in the reaction of oxygen electroreduction, that appears in decreasing of oxygen reduction potential EO2 and increasing of dynamic range of O2 electroreduction potentials.  The high electrocatalytic activity of Ce–TiO2 electrodes in the oxygen reduction process may be due to the formation of catalytically active centers which activity may decrease in the presence of an amorphous phase. The correlation between photo- and electrocatalytic properties and structural changes occurring in Ce–TiO2 films on increasing the cerium content is observed.  The electrodes investigated were distinguished by a high sensitivity to dissolved oxygen ((4-5)∙10-6 g·l-1) and high reproducibility of characteristics in long-time cycling. These electrodes promise much as reusable electrode materials in electrochemical sensors for the determination of oxygen in liquids. |
| doi_str_mv | 10.33609/0041-6045.85.11.2019.63-72 |
| first_indexed | 2025-09-24T17:43:22Z |
| format | Article |
| fulltext |
Фізична хімія
ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11 63
UDC 544.52: 546.21 doi: 10.33609/0041-6045.85.11.2019.63-72
V.S.Vorobets*, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko,
I.A.Rusetskyi
SYNTHESIS, PHOTO- AND ELECTROCATALYTIC PROPERTIES OF
NANOSTRUCTURED Ce–TiO2 FILMS
V.I.Vernadsky Institute of General and Inorganic Chemistry of National Academy of Sciences of
Ukraine, 32/34 Academic Palladin Avenue, Kyiv, 03142, Ukraine
*e-mail: vorobetsvs@i.ua
Electrocatalytic films based on nanodispersed titanium dioxide modified by Ce(III) were
synthesized by sol-gel method and characterized by X-ray diffraction and ultraviolet-
visible photocurrent spectra. The average size of nanoparticles was no more thаn 11 nm.
The XRD results indicated that TiO2 and Ce–TiO2 electrodes with Ce concentrations up
to 5 % calcined at 500°C consisted of anatase as the unique phase. The photocurrent
spectra of the Ce–TiO2 electrodes (0 ≤ Ce concentration ≤ 2% mol.) showed a stronger
current in the UV range and a shift in the flat-band potential (Еfb) towards more negative
values than that of TiO2 electrodes. Electrocatalytic properties of TiO2 and Ce–TiO2
electrodes were investigated in the process of oxygen electroreduction. It has been found
by I–E curves measurements that the potential of oxygen reduction changes with the film
composition. Modifying of TiO2 films by Ce(III) improves catalytic activity of Ce–TiO2
electrodes ( Ce concentration up to 2% mol.) in the reaction of oxygen electroreduction,
that appears in decreasing of oxygen reduction potential EO2 and increasing of dynamic
range of O2 electroreduction potentials. The high electrocatalytic activity of Ce–TiO2
electrodes in the oxygen reduction process may be due to the formation of catalytically
active centers which activity may decrease in the presence of an amorphous phase. The
correlation between photo- and electrocatalytic properties and structural changes occur-
ring in Ce–TiO2 films on increasing the cerium content is observed. The electrodes in-
vestigated were distinguished by a high sensitivity to dissolved oxygen ((4-5)∙10-6 g·l-1)
and high reproducibility of characteristics in long-time cycling. These electrodes prom-
ise much as reusable electrode materials in electrochemical sensors for the determination
of oxygen in liquids.
K e y w o r d s: titanium dioxide, cerium, oxygen electroreduction, catalytic activity,
photosensitivity.
INTRODUCTION.Titanium dioxide is a promising material for application in
© V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko,
I.A.Rusetskyi, 2019
mailto:vorobetsvs@i.ua
V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko, I.A.Rusetskyi
64 ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11
optical and protective coatings, electrochem-
ical devices, as oxygen reduction catalyst
environmental photocatalysis, for the gen-
eration of electricity in the solar cells, gas
sensors,etc. The catalytic activity of titania
increases greatly when rare earth do-
pednanoparticles are used [1]. In this paper
we present study results of photo- and
electrocatalytic properties of electrodes
based on nanostructured titanium oxide films
modified by Ce.
EXPERIMENT AND DISCUSSION OF
THE RESULTS. Nanoscale titanium dioxide
TiO2 was synthesized by the sol-gel method
from titanium(IV) tetraisopropoxide in the
presence of the non-ionic surfactant Triton
X-100 [1]. An appropriate amount of Triton
X-100 was dissolved in ethanol (EtOH), af-
ter which acetic acid (AcOH) was added to
the solution. Then a titanium dioxide precur-
sor, titanium tetraisopropoxide (TTIP), was
added to the solution with vigorous stirring.
The molar ratio of the components was Tri-
ton X-100 : EtOH : AcOH : TTIP=0.5 : 69 :
6 : 1. To prepare TiO2 modified with cerium
ions, appropriate amounts of CeCl3 were
added into the precursor to reach the cerium
content of 0.5, 1, 2, 3, 5, 8 and 10% mol. To
fabricate TiO2 and Ce-TiO2 films, transpar-
ent sol was deposited on pre-prepared Ti
substrates and annealed in air at 500 °C.
Preliminary preparation of Ti substrate
included degreasing with acetone or carbon
tetrachloride, as well as chemical etching in
a mixture of HF and HNO3 acids for 3-5
minutes, which helps to remove the surface
oxide layer from the titanium foil, and also
provides better adhesion of TiO2 sol with
substrate. Sol was deposited on a conducting
substrate by the immersion method. To this
end, the first sol layer was deposited on a
prepared substrate; after that, the electrode
was dried in an SNOL 58/350 laboratory ov-
en at 120 ºC for 10 minutes. This procedure
was repeated 10 times. The electrodes with
deposited layers based on Ce–TiO2 sol were
annealed in air in an SNOL 7.2/900 muffle
furnace at t=500ºC for 30 min and cooled at
room temperature.
The phase composition and crystal struc-
ture of the obtained samples were studied by
means of a DRON-3M diffractometer (mon-
ochromatic CuKα radiation with nickel filter,
λ=1.5418Ǻ) at 30 kV, 20 mA in an angle
range of 2θ=10–90°. To identify the
diffractograms, the JCPDS database was
used. The diffractograms were processed us-
ing the computer programs X-Ray and
Match. The size of crystallites (coherent-
scattering regions) of the obtained samples
was calculated from the Scherrer equation
using the most intense (101) anatase diffrac-
tion peak.
The photosensitivity of the samples and
their photoelectrochemical characteristics
(spectral dependence of the photocurrent
quantum yield and flat-band potential) were
estimated from photocurrent values in wave-
length range of 250–600 nm. The
photoelectrochemical investigations were
carried out in 1N KCl solution in a quartz
electrochemical cell with separated cathode
and anode spaces using an MDR-2 mo-
nochromator and a DKSSh 500 high-
pressure xenon lamp. An Ag/AgCl electrode
was used as a reference electrode, and a plat-
inum electrode was used as an auxiliary
electrode.
The electrocatalytic activity of elec-
trodes based on TiO2 and Ce-TiO2 films dur-
Synthesis, photo- and electrocatalytic properties of nanostructured Ce–TiO2 films
ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11 65
ing oxygen electroreduction and the possibil-
ity of using them in sensing system were
studied under potentiodynamic conditions
using a PC-based electrochemical setup,
which had the following characteristics:
measured currents 2·10–9 ÷ 10–1 А, potential
scan rate 0.01÷50 mV·s-1, working electrode
potential range -4 ÷ +4 V. TiO2- and Ce-
TiO2 – based films deposited on a titanium
substrate were used as a working electrode.
The measurements were made in a 0.9%
NaCl solution.
Structure of powders. X-ray patterns of
powders obtained from the precursors of
TiO2 and Ce–TiO2 films with a cerium con-
tent of 0.5-10 % mol. are shown in fig 1. In
the X-ray patterns of both the initial TiO2
and cerium-doped TiO2 there are reflections
typical of the crystalline anatase phase
(JCPDS, no 21-1272). The diffraction peaks
at 25,3°, 37,8°, 48,0°, 53,9°, 55,0° and 62,7°
are identified as the (101), (104), (200),
(105), (211) and (204) reflections of the
crystalline anatase phase. The diffraction
peaks corresponding to the crystalline ceri-
um phase in Ce–TiO2 samples are not ob-
served (fig 1).
Fig 1. X-ray patterns of powders obtained at 500
ºC from precursors of films with a cerium con-
tent of (% mol.) : 1–0; 2 –0,5; 3–1; 4–2; 5–3; 6–
5; 7–8; 8–10.
As follows from Refs [2–8], cerium can
be in the amorphous state [2], in the form of
crystals of the cubic CeO2 phase [3–5], but
the incorporation of cerium ions into the
anatase lattice is also possible [6]. It should
be noted that the method used for making
samples has a strong influence on the crys-
tallization of mixed TiO2 and Ce–TiO2 ox-
ides. When the sol-gel method is used, the
cubic CeO2 phase, besides anatase, crystal-
lizes in the presence of surfactants at a higer
molar Ce content (≥ 10 %mol.) [7, 8] and
at a higher temperature than when using
acids [2,4].
It can be seen that the anatase reflections
become less intense with increasing Ce con-
tent при 2θ > 55º (fig 1). According to the
data of the authors of [2], who synthesized
Ce–TiO2 powders by the sol-gel method us-
ing Triton X-114 in cyclohexane without us-
ing an acid, this indicates that cerium in Ce–
TiO2 powders is probably present as an
amorphous phase, and that the titanium diox-
ide crystallite size depends on the Ce
content.
The broadening of diffraction peaks in-
dicates that the obtained powders are
nanocrystalline. The mean crystallite size
was determined by the broadening of the
most intense (101) peak from the Scherrer
equation:
θβ
λ
cos
kd = ,
where d is the mean crystallite size, k is a
constant (k = 0.9), β is peak half-width, λ
and θ are X-ray wavelength and reflection
agle respectively. The (101) diffraction peak
half-width was determined as the half-width
of the Lorentzian fitting function, which de
V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko, I.A.Rusetskyi
66 ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11
scribes the peak profile. The description of
the profile of this diffraction peak by the
Gaussian function was less satisfactory. The
particle sizes calculated by the above proce-
dure for TiO2 and Ce–TiO2 samples with a
Ce content of o.5, 1, 2, 3, 5 %mol. are listed
in table 1. The effect of the Ce content on
the crystallite size D of anatase TiO2 is given
in table 1.
As follows from table 1, when the
T a b l e 1.
Structural properties of investigated materials determined by using XRD
Composition 2θ,º D, Ǻ Lattice parameters
a(Ǻ) c(Ǻ) V(Ǻ3)
TiO2
25,35
108.1
3.7826
9.5057
136.01
0.5%Ce/TiO2 25,33 97.8 3.7831 9.5175 136.21
1%Ce/TiO2 25,31 97.2 3.7854 9.5236 136.46
2%Ce/TiO2 25,30 82.6 3.7861 9.5230 136.50
3%Ce/TiO2 25,33 84.7 3.7848 9.5271 136.47
5%Ce/TiO2
25,34 72.6 3.7818 9.5372 136.40
Ce content of modified samples is increased,
the particle size decreases, which may be
due to the presence of Ce–O–TiO2 bonds,
which impede the growth of crystalline
grains [3,4].
The X-ray spectra of samples with a Ce
content of 8 and 10 % mol. exhibit a weak
broad peak at 2θ = 70º (fig 1, curves 7, 8),
which corresponds to the presence of very
small (~ 1 nm) CeO2 crystallites, which
agrees with the data of [2,5]. In spite of the
fact that in the samples with high Ce content
(8 and 10% mol.), cerium is in an amor-
phous phase, as was shown above, cubic
CeO2 crystallites can nucleate in the bulk of
TiO2 anatase [5]. However, they are difficult
to detect by XRD because of very small size,
which is below the limit of detection by
XRD.
The X-ray patterns of Ce–TiO2 samples
with a Ce content of up to 2 %mol. , an
nealed at 500 0C (fig 1) exhibited a broaden-
ing of typical anatase peaks and their shift to
smaller angles (table 1, fig 2).
Fig 2. Decomposition of the (101) peak by
means of the Lorentz function in X-ray patterns
of films: 1 – TiO2; 2 – 2%Ce–TiO2.
Synthesis, photo- and electrocatalytic properties of nanostructured Ce–TiO2 films
ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11 67
This indicates that cerium ions are in-
corporated into the anatase lattice [6],
though the difference in ionic radius be-
tween titanium (Ti4+ = 0.68 Ǻ) and cerium
(Ce4+ = 0.92 Ǻ) is large. The values of the
lattice parameters a and c as well as lattice
volume V, calculated with the aid of the
program X-Ray, increase with increasing the
cerium content of samples to 2% (table 1),
which also indicates the possibility of Ce4+
ion incorporation into the anatase lattice.
The obtained data agree with the data of the
authors of [6], who showed that in spite of
the large difference in ionic radius, Ce ions
can replace Ti4+ ions in the anatase lattice to
form (≡ Ti–O–Ce–O–Ti≡) bonds. In this
case, all TiO2 can be saturated with a rela-
tively small amount of Ce (because of the
large difference between the radii of Ti4+ and
Ce4+ ions); the rest of Ce is probably present
on the surface as CeO2. The authors of [6]
also observed an expansion of the anatase
unit cell for Ce-doped samples compared
with pure TiO2, which is an evidence of pos-
sible replacement of Ti4+ in the anatase lat-
tice by Ce4+ ions.
In our case, increasing the Ce content
(from 0,5 to 2 % mol.) in TiO2 also led to an
expansion of anatase lattice volume (table 1,
fig 3). The increase in anatase lattice volume
for the samples with a Ce content of up to
2 % mol. corresponds to the fact that Ce4+
ions are incorporated into the anatase lattice.
At a Ce content of about 2% mol., the TiO2
lattice is already saturated with Ce4+ ions,
and CeO2 is formed as an amorphous phase
or very small nuclei, which agrees with the
data of the authors of [4].
Photoelectrochemical properties of Ce-
TiO2 films. It has been found that the investi-
gated electrodes based on Ce-TiO2 films (ta-
ble 2, samples 1–6) were photosensitive in a
wavelength range of 250–400 nm, and that
the quantum yield η depended largely upon
the Ce content (table 2, fig 3) and was a
maximum for 1% Ce–TiO2 films.
Fig.3. The spectral dependences of photocurrent
quantum yield for TiO2 and Ce–TiO2 films with
cerium content, % mol.: 1–0; 2–0.5; 3–1; 4–2;
5–3; 6–5.
The flat-band potential Efb and band gap
energy Eg for indirect photo-transitions in
the forbidden band of TiO2 have been de-
termined from the photoelectrochemical cur-
rent quantum yield spectra of electrodes
based on obtained TiO2 and Ce–TiO2 films
(table 2). The value of the flat-band potential
Efb was determined from plots of photocur-
rent I vs potential E by extrapolating the lin-
ear portions of these plots to intersection
with the abscissa axis [9]. The value of Efb
allows one to estimate the change in the po-
sition of the conduction-band bottom of the
obtained electrodes and the energy of elec-
trons involved in reduction processes, in-
cluding the oxygen electroreduction process
[9]. To determine the band gap energy Eg,
the photoelectrochemical current quantum
yield spectra were reconstructed in the (hv
V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko, I.A.Rusetskyi
68 ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11
Т а b l e 2
Photoelectrochemical (η, Еg and Еfb) and electrocatalytic (Е1/2 and ΔЕ) properties of Ce–TiO2
electrodes depending on cerium content
№ Composition
Photocurrent
quantum yield
η, a.u.
Band
gap
Eg,еV
Flat band
potential
Еfb, V
Oxygen
half-wave
potential
Е1/2, V
Oxygen
reduction
range
ΔЕ,V
1 TiO2 0.37 3.0 -0.30 -0.70 0,10
2 0.5%Ce/TiO2 0.52 3.0 -0.32 -0.62 0,18
3 1%Ce/TiO2 0.76 3.0 -0.35 -0.55 0,24
4 2%Ce/TiO2 0.43 3.0 -0.30 -0.60 0,20
5 3%Ce/TiO2 0.31 3.0 -0.28 -0.63 0,20
6
5%Ce/TiO2 0.24 3.0 -0.25 -0.65 0,16
η)0.5~hv coordinates for indirect allowed
transitions in TiO2, where η is quantum yield,
and hv is quantum energy of light [9].
The value of quantum yield (η) for TiO2
and Ce–TiO2 samples was 0.24–0.76 (table
2). It should be noted that for the samples
with Ce content of 0.5, 1 and 2% mol. , a
significant increase in their photosensitivity
relative to unmodified TiO2, which mani-
fests itself by an increase in the quantum
yield of photoelectrochemical current, η (ta-
ble 2, samples 2– 4), and a shift of the spec-
tra to the long-wavelenth region (fig 3,
curves 2– 4) are observed. For the films with
a Ce content of >2%, the values of the quan-
tum yield of photocurrent were smaller
compared with unmodified TiO2 films (ta-
ble2, fig 3, curves 5, 6). In this case, the
band gap energy Eg of the investigated elec-
trodes did not change greatly (table 2). Ta
king this into consideration, we can consider
that modification with Ce ions leads to the
formation of photoactive defects in the for-
bidden band of TiO2, whose activity may
decrease with the formation of an amor-
phous phase (fig 3, curves 3, 5). The
explanation of why the value of Eg does not
change at different contents of Ce lies in its
usually much lower sensitivity with respect
to progressing structural changes [2].
Electrocatalytic properties of films. The
electrocatalytic properties of the obtained
films of cerium-modified titanium were
studied during oxygen electroreduction. This
process is the basis of the operation of elec-
trochemical O2 sensors, which are designed
for the determination of oxygen concentra-
tion in liquid media [8].
The polarization curves for electrodes
based on Ce–TiO2 films in physiologic solu-
Synthesis, photo- and electrocatalytic properties of nanostructured Ce–TiO2 films
ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11 69
tion 0.9%NaCl (pH 6.8) exhibited one
polarographic wave of current at potentials
of -0.5 to -1.0 V (vs silver-chloride elec-
trode) with limiting current corresponding to
oxygen reduction current (fig 4). At poten-
tials of E< - 1.0 V, a hydrogen evolution re-
action proceeded at the electrodes.
Fig 4. Polarization curves of oxygen
electroreduction on Ce–TiO2 electrodes: 1 –
5%Се–TiO2; 2 – 1%Се–TiO2. Potential scan
rate 10 mV·s-1. Potentials are given relative to
Ag/AgCl reference electrode.
Important characteristics of electrodes
for the analysis of dissolved oxygen concen-
tration are oxygen reduction potential or ox-
ygen reduction half-wave potential E1/2 on
the cathodic polarization curve and the width
of “electrochemical window”, ΔE (dynamic
potential range in which the oxygen content
of the solution can be analyzed). The value
of E1/2 should be minimal to eliminate possi-
ble electrochemical side reactions, and the
value of ΔE should be maximal to achieve
high electrode sensitivity and measurement
accuracy. From fig 4 it follows that in physi-
ologic NaCl solution (pH 6.8), the value of
E1/2 at the electrodes with cerium content of
1% is – 0.55 V and is minimal among the
obtained Ce–TiO2 electrodes. The dynamic
potential range of O2 reduction on these elec-
trodes was 0.24 V. The values of E1/2 and ΔE
for other electrodes are listed in table 2.
From table 2 it follows that modification
of TiO2 films with cerium increases the cata-
lytic activity of electrodes based on them in
the oxygen electroreduction reaction com-
pared with unmodified TiO2, which mani-
fests itself by a decrease in oxygen reduction
half-wave potential and an increase in the
dynamic range of O2 electroreduction. The
electrodes with cerium content of 1% (E1/2 =
-0.55V, ΔE = 0.24V) showed the maximum
electrocatalytic activity. At higher cerium
content of films (>2%), the electrocatalytic
activity of electrodes decreased (table 2). For
samples with 5% cerium content, the values
of E1/2 = -0.65V, ΔE = 0.16V were obtained.
The values of stationary potentials for
samples with 1% and 5% cerium content are
equal respectively to 0.17 V and 0.2 V. The
decrease in catalytic activity with increasing
cerium content may be due to, as in the case
of photosensitivity, to the formation of cata-
lytically active centers (crystalline defects),
whose activity decreases during the for-
mation of amorphous phase.
With repeated cycling of the potential,
the polarization characteristics of the Ce –
TiO2 electrodes remained almost unchanged
after the 3rd cycle, which indicates the high
stability of the obtained electrodes and the
possibility of using them to determine the
concentration of dissolved oxygen.
Thus, electrodes based on Ce–TiO2
films are distinguished by high electro-
catalytic activity and stability in the process
of oxygen reduction and are promising for
use in electrochemical oxygen sensors.
V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko, I.A.Rusetskyi
70 ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11
The variation of the electrocatalytic
(E1/2) and photoelectrochemical (η and Efb)
properties of the Ce–TiO2 films studied in
this work as a function of cerium content is
shown in fig 5.
Fig 5. Dependence of the electrocatalytic (E1/2)
and photoelectrochemical (η and Efb) properties
of Ce–TiO2 films on cerium content.
Thus, a correlation between photo- and
electrocatalytic properties and structural
changes occurring in Ce-TiO2 films on in-
creasing the cerium content is observed.
CONCLUSION. Powders and films of
TiO2 modified with Ce ions have been syn-
thesized by sol-gel method. The Ce–TiO2
powders with cerium content of 0.5–10% %
mol. (tannealing = 500 ºC) had an anatase crys-
tal structure with a crystallite size of up to
11nm.
Electrodes based on Ce–TiO2 films were
photosensitive in a wavelength range of
250–400 nm. For samples with Ce content of
0.5, 1 and 2 % mol., an increase in the val-
ues of photocurrent quantum yield and a
shift of spectra to the long-wavelength re-
gion compared with unmodified TiO2 were
observed. The subsequent increase of the ce-
rium content led to a decrease in the
photoactivity of samples.
The Ce–TiO2 films were distin-
guished by an increased catalytic activity in
the process of oxygen electroreduction,
which manifested itself by a decrease in ox-
ygen reduction half-wave potential and an
increase in the dynamic range of O2
electroreduction compared with unmodified
titanium dioxide films. An increase in
electrocatalytic activity was observed for ce-
rium ion concentrations of up to 1%; the
subsequent increase of the dopant content
led to decrease in the activity of samples
probably because of the formation of an
amorphous phase. Ce–TiO2 electrodes
showed high stability and reproducibility of
characteristics in the process of O2
electroreduction. Synthesized electrode
materials are most promising for use in elec-
trochemical sensors for the determination of
O2 in liquid media.
СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІ-
ТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУ-
РОВАНИХ ПЛІВОК Ce–TiO2
В.С. Воробець*, Г.Я. Колбасов, С.Я. Обло-
ватна, O.O. Саламаха, С.В. Карпенко,
I.A. Русецький
Інститут загальної та неорганічної хімії ім.
В.І. Вернадського НАН України, просп. Ака-
деміка Палладіна, 32/34, Київ, 03142, Україна
*е-mail:vorobetsvs@i.ua
Електрокаталітичні плівки на основі
нанодисперсного діоксиду титану, модифіко-
ваного Ce(III), синтезовані золь-гель методом
і охарактеризовані методами рентгенівської
дифракції (XRD) та спектроскопії
Synthesis, photo- and electrocatalytic properties of nanostructured Ce–TiO2 films
ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11 71
фотоелектрохімічного струму. Середній роз-
мір наночастинок не перевищу-вав 11 нм.
Результати XRD показали, що TiO2 і Ce–TiO2
порошки з концентраціями Ce до 5%,
прожарені при 500 °C, мали кристалічну
структуру анатазу. На спектрах фотоструму
Ce–TiO2 електродів (концентрація 0 ≤ Ce ≤
2% мол.) спостерігався більш сильний струм
в УФ-діапазоні і зсув потенціалу плоских зон
(Еfb) до більш нега-тивних значень, у
порівнянні з TiO2 – електродами. Електро-
каталітичні властивості електродів TiO2 і Ce–
TiO2 досліджувалися в процесі електро-
відновлення кисню. За допомогою I–E-
кривих було виявлено, що потенціал
електровідновлення кисню залежав від скла-
ду плівок. Модифікування плівок TiO2 за до-
помогою Ce (III) покращує каталітичну
активність електродів Ce–TiO2 (концентрація
Ce до 2 %мол.) у реакції електровідновлення
кисню, що проявляється у зменшенні потен-
ціалу відновлення кисню EO2 і збільшенні
динамічного діапазону потенціалів електро-
відновлення O2. Висока електрокаталітична
активність електродів Ce–TiO2 у процесі від-
новлення кисню , ймовірно, може бути обу-
мовлена утворенням каталітично активних
центрів, активність яких може зменшуватися
в присутності аморфної фази. Спостерігаєть-
ся взаємозв'язок між фото- та електрокаталі-
тичними властивостями та структурними
змінами, що відбуваються в плівках Ce–TiO2
при збільшенні вмісту церію. Досліджувані
електроди відрізнялися високою чутливістю
до розчиненого кисню (4–5)∙10-6 г•л-1) і ви-
сокою відтворюваністю характеристик при
тривалому циклюванні. Синтезовані елект-
родні матеріали можуть бути використані в
електрохімічних сенсорах для визначення O2
у рідких середовищах.
К л ю ч о в і с л о в а: діоксид титану, церій,
електровідновлення кисню, каталітична ак-
тивність, фоточутливість.
СИНТЕЗ, ФОТО- И ЭЛЕКТРОКАТАЛИТИ-
ЧЕСКИЕ СВОЙСТВА НАНОСТРУКТУРИ-
РОВАННЫХ ПЛЕНОК Cе–TiO2
В.С. Воробец*, Г.Я. Колбасов, С.Я. Облова-
тная, O.O. Саламаха, С.В. Карпенко,
И.A. Русецкий
Институт общей и неорганической химии
им. В.И. Вернадского НАН Украины, просп.
Академика Палладина, 32/34, Киев, 03142,
Украина
* е-mail:vorobetsvs@i.ua
Электрокаталитические пленки на осно-
ве нанодисперсного диоксида титана, моди-
фицированного Ce(ІІІ), синтезированы золь-
гель методом и охарактеризованы методами
рентгеновской дифракции (XRD) и спектро-
скопии фотоэлектрохимического тока. Ре-
зультаты XRD показали, что TiO2 и Ce–TiO2
порошки с концентрациями Ce до 5%, ото-
жженные при 500 °C, имели кристалличе-
скую структуру анатаза. На спектрах фотото-
ка Ce–TiO2 электродов (концентрация 0 ≤ Ce
≤ 2 % мол.) наблюдался более сильный ток в
УФ-диапазоне и смещение потенциала пло-
ских зон (Еfb) в сторону более отрицательных
значений, по сравнению с TiO2-электродами.
Повышение электокаталитической активно-
сти Ce-TiO2 электродов в процессе электро-
восстановления кислорода по сравнению с
немодифицированным TiO2 наблюдается для
пленок с концентрациями Ce до 5%. Синте-
зированные пленки могут быть использова-
ны в электрохимических сенсорах для опре-
деления O2 в жидких средах.
К л ю ч е в ы е с л о в а: диоксид титана, це-
рий, электровосстановление кислорода, ката-
литическая активность, фоточувствитель-
ность.
REFERENCES
V.S.Vorobets, G.Ya.Kolbasov, S.Ya.Oblovatna, O.O.Salamakha, S.V.Karpenko, I.A.Rusetskyi
72 ISSN 0041-6045. УКР . ХІМ . ЖУРН ., 2019, т . 85, № 11
1. ̌ Stengl V., Bakardjieva S., Murafa N. Prepa-
ration and photocatalytic activity of rare
earth doped TiO2 nanoparticles . Ma-
ter.Chem. Phys.2009. 114: 217.
2. Stathatos E., Lianos P., Tsakiroglou C.
Highly efficient nanocrystalline titania films
made from organic/inorganic nanocom-
posite gels. Micropor. Mesopor. Mat. 2004.
75: 255.
3. Matějová Lenka, Kočí Kamila, Reli Martin,
Čapek Libor, Hospodková Alice, Peikertová
Pavlína, Matěj Zdeněk, Obalová Lucie,
Wach Anna, Kuśtrowski Piotr, Kotarba
Andrzej. Preparation, characterization and
photocatalytic properties of cerium doped
TiO2: On the effect of Ce loading on the
photocatalytic reduction of carbon dioxide.
Appl. Catal., B. 2014. 152–153: 172.
4. Lin Jun, Yu Jimmy C. An investigation on
photocatalytic activities of mixed TiO2-rare
earth oxides for the oxidation of acetone in
air. J.Photochem. Photobiology A. 1998.
116(1): 63.
5. Fang J, Bi X, Si D, Jiang Z, Huang W.
Spectroscopic studies of interfacial struc-
tures of CeO2 –TiO2 mixed oxides. Appl
Surf Sci. 2007. 253: 8952.
6. Matejova L., Vales V., Fajgar R., Matej, Z.,
Holy V; Solcova O. Reverse micelles di-
rected synthesis of TiO2-CeO2 mixed oxides
and investigation of their crystal structure
and morphology. J. Solid State
Chem. 2013. 198: 485.
7. López T., Rojas F., Alexander-Katz R.,
Galindo F., Balankin A. S., Buljan A. Po-
rosity, structural and fractal study of sol–ge l
TiO2–CeO2 mixed oxides. J. Solid State
Chem. 2004. 177: 1873.
8. Pavasupree S., Suzuki Y., Pivsa-Art S.,
Yoshikawa S. Preparation and characteriza-
tion of mesoporous TiO2–
CeO2 nanopowders respond to visible wave-
length. J. Solid State Chem. 2005. 178: 128.
9. Kolbasov G.Ya., Vorobets V. S., Korduban
A. M., Shpak A. P., Medvedskii M. M.,
Kolbasova I. G., Linyucheva O. V. Elec-
trodes Based on Nanodispersed Titanium
and Tungsten Oxides for a Sensor of Dis-
solved Oxygen. Russ. J. Appl. Chem. 2006.
79(4): 596.
Надійшла 11.07.2019
https://www.sciencedirect.com/science/article/pii/S0926337314000216#!
https://www.sciencedirect.com/science/article/pii/S0926337314000216#!
https://www.sciencedirect.com/science/article/pii/S0926337314000216#!
https://www.sciencedirect.com/science/journal/09263373/152/supp/C
https://www.sciencedirect.com/science/article/abs/pii/S1010603098002895#!
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| id | oai:ojs2.1444248.nisspano.web.hosting-test.net:article-104 |
| institution | Ukrainian Chemistry Journal |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2026-07-23T01:00:56Z |
| publishDate | 2019 |
| publisher | V.I.Vernadsky Institute of General and Inorganic Chemistry |
| record_format | ojs |
| resource_txt_mv | ucjorgua/df/7783ee1d6bba4151dfa5db2f67e2cedf.pdf |
| spelling | oai:ojs2.1444248.nisspano.web.hosting-test.net:article-1042026-07-22T08:23:41Z SYNTHESIS, PHOTO- AND ELECTROCATALYTIC PROPERTIES OF NANOSTRUCTURED Ce–TiO2 FILMS СИНТЕЗ, ФОТО- И ЭЛЕКТРОКАТАЛИТИЧЕСКИЕ СВОЙСТВА НАНОСТРУКТУРИРОВАННЫХ ПЛЕНОК Cе–TiO2 СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 Vorobets , Vera Kolbasov, Gennadii Oblovatna , Svitlana Salamakha, Oleg Karpenko, Sergii Rusetskyi, Ihor titanium dioxide, cerium, oxygen electroreduction, catalytic activity, photosensitivity. Electrocatalytic films based on nanodispersed titanium dioxide modified by Ce(III) were synthesized by sol-gel method and characterized by X-ray diffraction and ultraviolet-visible photocurrent spectra. The average size of nanoparticles was no more thаn 11 nm. The XRD results indicated that TiO2 and Ce–TiO2 electrodes with Ce concentrations up to 5 % calcined at 500°C consisted of anatase as the unique phase. &nbsp;The photocurrent spectra of the Ce–TiO2 electrodes (0 ≤ Ce concentration ≤ 2% mol.)&nbsp; showed a stronger current in the UV range and a shift in the flat-band potential (Еfb) towards more negative values than that of&nbsp; TiO2 electrodes. Electrocatalytic properties of TiO2 and Ce–TiO2 electrodes were investigated in the process of oxygen electroreduction. It has been found by I–E curves measurements that the potential of oxygen reduction changes with the film composition. Modifying of TiO2 films by Ce(III) &nbsp;improves catalytic activity of Ce–TiO2 electrodes ( Ce concentration up to 2% mol.) &nbsp;in the reaction of oxygen electroreduction, that appears in decreasing of oxygen reduction potential EO2 and increasing of dynamic range of O2 electroreduction potentials.&nbsp; The high electrocatalytic activity of Ce–TiO2 electrodes in the oxygen reduction process may be due to the formation of catalytically active centers which activity may decrease in the presence of an amorphous phase. The correlation between photo- and electrocatalytic properties and structural changes occurring in Ce–TiO2 films on increasing the cerium content is observed. &nbsp;The electrodes investigated were distinguished by a high sensitivity to dissolved oxygen ((4-5)∙10-6 g·l-1) and high reproducibility of characteristics in long-time cycling. These electrodes promise much as reusable electrode materials in electrochemical sensors for the determination of oxygen in liquids. V.I.Vernadsky Institute of General and Inorganic Chemistry 2019-12-16 Article Article Physical chemistry Физическая xимия Фізична xімія application/pdf https://ucj.org.ua/index.php/journal/article/view/104 10.33609/0041-6045.85.11.2019.63-72 Ukrainian Chemistry Journal; Vol. 85 No. 11 (2019): Ukrainian Chemistry Journal; 63-72 Украинский химический журнал; ##issue.vol## 85 ##issue.no## 11 (2019): Украинский химический журнал; 63-72 Український хімічний журнал; Том 85 № 11 (2019): Український хімічний журнал; 63-72 2708-129X 2708-1281 en https://ucj.org.ua/index.php/journal/article/view/104/68 Copyright (c) 2019 Vera Vorobets , Gennadii Kolbasov, Svitlana Oblovatna , Oleg Salamakha, Sergii Karpenko, Ihor Rusetskyi https://creativecommons.org/licenses/by-nc/4.0 |
| spellingShingle | Vorobets , Vera Kolbasov, Gennadii Oblovatna , Svitlana Salamakha, Oleg Karpenko, Sergii Rusetskyi, Ihor СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title | СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title_alt | SYNTHESIS, PHOTO- AND ELECTROCATALYTIC PROPERTIES OF NANOSTRUCTURED Ce–TiO2 FILMS СИНТЕЗ, ФОТО- И ЭЛЕКТРОКАТАЛИТИЧЕСКИЕ СВОЙСТВА НАНОСТРУКТУРИРОВАННЫХ ПЛЕНОК Cе–TiO2 |
| title_full | СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title_fullStr | СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title_full_unstemmed | СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title_short | СИНТЕЗ, ФОТО- ТА ЕЛЕКТРОКАТАЛІТИЧНІ ВЛАСТИВОСТІ НАНОСТРУКТУРОВАНИХ ПЛІВОК Ce–TiO2 |
| title_sort | синтез, фото- та електрокаталітичні властивості наноструктурованих плівок ce–tio2 |
| topic_facet | titanium dioxide cerium oxygen electroreduction catalytic activity photosensitivity. |
| url | https://ucj.org.ua/index.php/journal/article/view/104 |
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