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EFFECT OF VOLTAGE AND TEMPERATURE ON THE GROWTH OF
TIO2 NANOTUBES
Djumagulov Sh.KX.
Khamidov A.M.
Nurmanov S.E.
Rozimuradov O.N.
National University of Uzbekistan, Uzbekistan
Turin Polytechnic University in Tashkent
https://doi.org/10.5281/zenodo.15672705
Abstract:
Since TiO
2
based nanotubes are widely used in industry, the
anodic growth of nanotubes was studied in an organic electrolyte consisting of
NH4F and ethylene glycol at different temperatures for a period of 3 hours from
40 to 60 V. The dependence of the length and diameter of the formed nanotube
on temperature was consistent with the Arrhenius equation. It can be seen that
the activation energy for nanotube growth is much larger than that for diameter
growth and is linearly proportional to the anodizing voltage.
Keywords:
Electrochemical anodizing, voltage and temperature, electronic
and ionic conductivity.
Introduction
Titanium dioxide has attracted great interest due to its non-toxicity and
chemical inertness for applications in various fields, including paints,
sunscreens, water separation methods [1], and lithium-ion batteries [2]. It is
known that two chemical processes occur in the formation of TiO2 nanotubes:
the first is the chemical dissolution of TiO2. The second is the formation of an
oxide layer under the influence of an electromagnetic field [3]. Ruixia and her
students studied the dependence of both mechanisms on the anodizing voltage,
temperature, and time. They found that this electrochemical process is due to
the dissolution of the oxide layer before the formation of nanotubes at high
temperatures [4-5].
Experimental part
Titanium foil (thickness 100 mm, purity 99.5%, (Shuangmu Technology
Co.LTD) was used as the anode and platinum was used as the counter electrode.
In the anodizing process, the ratio of the anode to the cathode surface is (4:52).
Since the cathode surface is much larger than the anode surface, the current
density is evenly distributed on it. To clean the surface of the foil from various
roughnesses and impurities, it was cleaned in a solution of HF:NNO3:H2O =
1:1:2 for 15 minutes (GT Sonic-D6, AC-220-240V). Then it was washed in
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
20
distilled water for another 15 minutes and dried in the open air for one hour.
After that, an electrolyte consisting of 2% water, 98% ethylene glycol solution
and up to 0.3% NH4F was prepared for it. The distance between the electrodes
was set at intervals of 0.5, 1.0 and 1.5 cm, respectively. During the anodizing
process, the current-time curves were recorded by a computerized calculation
system (potentiostat: (Model-SS-350M, S/N 21121062)
Below are diagrams of the dependence of nanotube length on temperature
at different voltages of 40, 50, and 60 V (Figure 1).Bunda 40 V kuchlanishda, 12
sekda boshlangan oksidlanish jarayoni 5 µmdan boshlanib, 60 ºC da 14 µmgacha
It can be seen that the length of the oxide layer is 4.7 µm to 10 µm starting at 50
ºC, 12 sec, 2.8 µm to 6.8 µm starting at 40 ºC, and 12 sec, 1.9 µm to 2.6 µm
starting at 30 ºC (Figure 1 (b)). This shows that the highest oxide layer is formed
at 60 ºC.
Figure 1.
Temperature dependence diagrams of nanotube length obtained at
three different voltages: (a) 40, (b) 50, and (c) 60 V.
The length of the oxide layer formed at different temperatures at 50 V is
shown (Figure 1 (b)). At 60 ºC, it can be seen that it started at 12 seconds and
formed from 5.3 µm to 18.3 µm. This proves that the highest oxide layer is
formed at 60 ºC. At 60 V, it can be seen that the longest oxide layer is formed at
60 ºC (Figure 1 (c)). This is due to the higher mobility of ions in the solution and
the higher diffusion constant at higher temperatures.
Referanse:
1.
Shankar, K., Basham, J. I., Allam, N. K., Varghese, O. K., Mor, G. K., Feng, X., &
Grimes, C. A. Recent advances in the use of TiO2 nanotube and nanowire arrays
for oxidative photoelectrochemistry. (2009). The Journal of Physical Chemistry
C, 113(16), 6327-6359.
2.
Allam N. K., Shankar K., Grimes C. A. Photoelectrochemical and water
photoelectrolysis properties of ordered TiO2 nanotubes fabricated by Ti
anodization in fluoride-free HCl electrolytes //Journal of Materials Chemistry. –
2008. – Т. 18. – №. 20. – С. 2341-2348.
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
21
3.
Yu, J., Fan, J., & Lv, K. (2010). Anatase TiO2 nanosheets with exposed
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Jennings, J. R., Ghicov, A., Peter, L. M., Schmuki, P., & Walker, A. B. (2008).
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130(40), 13364-13372.
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