• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.243-252
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• 2021

With increasingly strict requirements for advanced energy storage devices in electric vehicles (EVs) and stationary energy storage systems (EES), the development of lithium-ion batteries (LIBs) with high power density and safety has become an urgent task. Because the performance of LIBs is determined primarily by the physicochemical characteristics of its electrode material, TiO₂, owing to its excellent stability, high safety levels, and environmentally friendly properties, has received significant attention as an alternative material for the replacement of commercial carbon-based anode materials. In particular, self-organized TiO₂ micro and nanostructures prepared by anodization have been intensively investigated as promising anode materials. In this review, the mechanism for the formation of anodic TiO₂ nanotubes and microcones and the parameters that influence their morphology are described. Furthermore, recent developments in anodic TiO₂-based composites as anode electrodes for LIBs to overcome the limitations of low conductivity and specific capacity are summarized.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.30-30
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.38-38
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• 2001

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.133-133
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• 2003

• Journal of the Korean institute of surface engineering
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• v.51 no.3
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• pp.157-163
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• 2018

The anodic $TiO_2$ layers which are prepared in various anodization conditions exhibit their specific color depending on the thickness of $TiO_2$. In this study, the relationship between the color of $TiO_2$ layer, which is grown by PEO (Plasma electrolytic oxidation), and the thickness of the $TiO_2$ layer is investigated. To evaluate the color change of the $TiO_2$ layer, the value of color ($dE^*ab$) is measured and calculated by spectrophotometer and chromameter. As a result, it is found that $dE^*ab$ values and thickness of $TiO_2$ layers form a linear relationship with meaningful formular. This formula can be helpful to quantify the thickness of the $TiO_2$ layer by the numerical $dE^*ab$ values. In this process, the spectrophotometer shows more precise results than the chromameter dose. If fluoride ions ($F^-$) are included in the electrolyte, it will affect the $dE^*ab$ values of the $TiO_2$. layer. This is against the propensity, which is analyzed by XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy). It is important that the formular suggested in this study provides other metals which can be also anodized with the possibility of quantifying the thickness of the $TiO_2$ layer by the $dE^*ab$ values.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.266-267
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• 2014

$TiO_2$ 기반의 DSA 전극에 촉매제를 동시에 도핑할 수 있는 양극산화 단일 공정을 연구하였다. 에틸렌 글리콜 용매하에 $KRuO_4$와 $NH_4F$를 전해질로 사용하여 타이타늄을 양극산화 할 때 도핑과 나노구조 제어를 동시에 수행할 수 있었다. TEM과 XPS 분석 결과, 균일한 Ru 산화물이 $TiO_2$ 구조 내에 분포함을 확인할 수 있었다.

• Journal of the Korean Ceramic Society
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• v.20 no.1
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• pp.31-36
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• 1983

The photoelectrochemical conversion by polycrystalline $TiO_2$ electrodes is effected by applied voltage oxidized $TiO_2$ thickness temperature and concentration of a, P. E. C cell. Anodic current starts at -0.8V in 1N-NaOH solu-tion and photocurrent appears around 420nm frequency. And the emf of the cell drops with the rate of 58.5mV/PH.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.282-283
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• 2003

TiO$_2$ 박막은 높은 굴절률과 유전 상수를 가지며, 가시광선과 근적외선 영역에서 우수한 투과성을 나타낸다. 따라서, 전기적, 광학적 특성이 우수한 광학코팅에 응용되고 있다. 또한 화학적으로 안정하고 비교적 큰 에너지 밴드 갭을 지닌 반도체 물질로서 유전체 다층 박막을 제작하는데 있어서 중요한 물질로 사용되고 있다. TiO$_2$ 박막을 제작하기 위한 물리적인 방법으로는 sputtering, anodic 또는 thermal, e-beam evaporation 등이 이용되고 있으며, sol-gel법, CVD 등과 같은 화학적인 방법도 이용되고 있다. (중략)

• Corrosion Science and Technology
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• v.6 no.6
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• pp.311-315
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• 2007

The anodic polarization behavior of equiatomic TiNi shape memory alloy with pure titanium as a reference material was investigated by means of open circuit potential measurement and potentiodynamic polarization technique. And the structure of passive films on TiNi intermetallic compounds was also conducted using AES and ESCA. While the dissolved Ni(II) ion did not affect the dissolution rate and passivation of TiNi alloy, the dissolved Ti(III) ion was oxidated to Ti(IV) ion on passivated TiNi surface at passivation potential. It has also been found that the Ti(IV) ion increases the steady state potential, and passivates TiNi alloy at a limited concentration of Ti(IV) ion. The analysis by AES showed that passive film of TiNi alloy was composed of titanium oxide and nickel oxide, and the content of titanium was three times higher than that of nickel in outer side of passive film. According to the ESCA analysis, the passive film was composed of $TiO_2$ and NiO. It seems reasonable to suppose that NiO could act as unstabilizer to the oxide film and could be dissolved preferentially. Therefore, nickel oxide contained in the passive film may promote the dissolution of the film, and it could be explained the reason of higher pitting susceptibility of TiNi alloy than pure Ti.

• Journal of the Korean institute of surface engineering
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• v.51 no.1
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• pp.27-33
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• 2018

In the present work, we demonstrate the feasibility to form large inner diameter $TiO_2$ nanotubes by anodization of Ti in a HF/ethylene glycol electrolyte. In order to achieve the large inner diameter $TiO_2$ nanotubes, optimization of the anodization condition is required. We discover the key factors in the formation of large inner diameter $TiO_2$ nanotubes are concentration of water in the electrolyte, anodization temperatures, and high-applied potential. Under optimum conditions, the inner diameters of $TiO_2$ nanotubes are 379 nm. The results are approximately 3 folders larger than the general case.