• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2343-2347
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• 2015

This paper reports the effect of Titanium dioxide (TiO₂) nanoparticles on a TiO₂ sol-gel Schottky diode. TiO₂ nanoparticles were blended with TiO₂ sol-gel to fabricate the Schottky diode. TiO₂ nanoparticles showed strong anatase and rutile X-ray diffraction peaks. However, the mixture of TiO₂ sol-gel and TiO₂ nanoparticles exhibited no anatase and rutile peaks. The forward current of the Schottky diode drastically increased as the concentration of TiO₂ nanoparticles increased up to 10 wt. % and decreased after that. The possible conduction mechanism is more likely space charge limited conduction.

• Korean Journal of Metals and Materials
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• v.47 no.3
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• pp.182-187
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• 2009

The molten salt electrolysis is applied to reduce titanium dioxide to titanium metal using calcium chloride as an electrolyte and the reaction mechanism of the reduction process is examined by analyzing the reaction products. The process conditions to obtain titanium metal for $900^{\circ}C$ correspond to 2.9~3.2 V and 24 hours. The reaction products for 2.9 V at $900^{\circ}C$ include irregular-shaped titanium oxides such as $Ti_4O_7$, $Ti_3O_5$ and $Ti_2O_3$ and polyhedral $CaTiO_3$. Using these microstructure analysis, the sequential reaction mechanism for the electrochemical reduction of titanium dioxide to titanium is proposed.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.690-696
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• 2001

$TiO_2$ coated coal fly ash has been prepared in order to develop the low price $TiO_2$ photocatalyst and spread out its utilizing field. $TiO_2$ particles is coated on the surface of coal fly ash by precipitation method. In this method, $TiCl_4$ aqueous solution was used as a titanium stock solution and $NH_4HCO_3$ was used as a precipitant. The titanium hydroxide precipitated on the surface of coal fly ash in these neutralizing reaction process was oxidized by heat treatment in temperature ranges of $300~700^{\circ}C$. The crystal structure of the generated titanium dioxide showed anatase type. The crystal size of titanium dioxide increased with raising the temperature of heat treatment, but the removal ability of NO gas decreased. When the titanium dioxide was heated at temperature ranges of $300~ 400^{\circ}C$ for 2 hours, the crystal size of titanium dioxide appeared about 9nm, and the removal rate of NO gas showed 85~ 92%. The whiteness of $TiO_2$ coated coal fly ash increased with raising the coating rate of titanium dioxide and the temperature of heat treatment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.323-324
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• 2023

The properties of cement mortar mixed with manganese-doped titanium dioxide nanowires (TiO₂(Mn)-NWs) were investigated in this study. The TiO₂(Mn)-NWs were synthesized using solvo-thermal synthesis and electro-spinning techniques. The TiO₂(Mn)-NWs at weights of 1%, ₂%, and 3% of the cement were respectively mixed into the cement mortar. The results showed that as the amount of TiO₂(Mn)-NWs increased, the flow value of the cement mortar was decreased and the setting time of cement mortar was accelerated. Moreover, as the amount of TiO₂(Mn)-NWs increased, the compressive strength of cement mortar was increased and the efficiency of acetaldehyde removal was improved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.230-231
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• 2006

In this paper, we examined effects by the binder in manufacturing titanium dioxide film for dye sensitized solar cell. Binder(PEG and PEO) was added the amount of 10-40wt% to commercial $TiO_2$ (P25), Respectively. All of $TiO_2$ film was showed porous structure owing to the addition of binders. But the difference of film's porosity could not be confirmed. The transmittance of $TiO_2$ film was decreased with the increase of binder's amount, generally. In case of 20wt%, however. The transmittance of $TiO_2$ films was showed the highest value.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.353-353
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• 2011

Titanium dioxide is a suitable material for industrial use at present and in the future because titanium dioxide has efficient photoactivity, good stability and low cost [1]. Among the three phases (anatase, rutile, brookite) of titanium dioxide, the anatase form is particularly photocatalytically active under ultraviolet (UV) light. In fabrication of photocatalytic devices based on catalytic nanodiodes [2], it is challenging to obtain a photocatalytically active TiO2 thin film that can be prepared at low temperature (< 200$^{\circ}C$). Here, we present the synthesis of a titanium dioxide film using TiO2 nanoparticles and sol-gel methods. Titanium tetra-isopropoxide was used as the precursor and alcohol as the solvent. Titanium dioxide thin films were made using spin coating. The change of atomic structure was monitored after heating the thin film at 200$^{\circ}C$ and at 350$^{\circ}C$. The prepared samples have been characterized by X-ray diffraction (XRD), scanning electron microcopy, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy (UV-vis), and ellipsometry. XRD spectra show an anatase phase at low temperature, 200$^{\circ}C$. UV-vis confirms the anatase phase band gap energy (3.2 eV) when using the photocatalyst. TEM images reveal crystallization of the titanium dioxide at 200$^{\circ}C$. We will discuss the switching behavior of the Pt /sol-gel TiO2 /Pt layers that can be a new type of resistive random-access memory.

• Journal of the Korean Ceramic Society
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• v.28 no.9
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• pp.721-729
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• 1991

SnO2-TiO2(Pt or Pd), as raw material for hydrocarbon gas sensors, was prepared by a coprecipitation method. The SnO2-TiO2-based thick film gas sensors were made by screen printing technique. The titanium dioxide synthesized was shown to be anatase structure from XRD peaks and was transformed to rutile structure between 700$^{\circ}C$ and 1000$^{\circ}C$. Titanium dioxide in SnO2-TiO2 thick films devices plays a very important role in the enhancement of the sensitivity to CH4 and C4H10. In the case of SnO2-TiO2(Pt) sensors, titanium dioxide that was rutile structure enhanced the sensitivity of the thick film to CH4. Platinum added to the raw powder at coprecipitation (as chloroplatinic acid VI hydrate) improved the gas sensitivity to hydrocarbon gases. Therefore, it is expected that the SnO2-TiO2(Pt) thick film sensors fabricated in this experiment could be put into practical use as LPG (primary component : C4H10 and C3H8) and LNG (primary component : CH4) sensors.

• Environmental Engineering Research
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• v.13 no.2
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• pp.85-92
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• 2008

In this present study, we have synthesized Fe-containing AC(activated carbon)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as a titanium source to Fe treated AC through an impregnation method. The result of the textural surface properties demonstrates that there is a slight decrease in the BET surface area of composite samples with an increase of the amount of Fe treated. The surface properties of scanning electron microscope (SEM) presented a characterization of a porous texture on the Fe-containing AC/$TiO_2$ composites and homogenous compositions for Fe and titanium dioxide distributed on the sample surfaces. Fe compound peaks and a titanium dioxide structure were observed in the X-ray diffraction patterns for the Fe-containing AC/$TiO_2$ composites. The results of chemical elemental composition for the Fe-containing AC/$TiO_2$ composites showed that most of the spectra for these samples gave stronger peaks for C, O, treated Fe components and Ti metal than that of any other elements. From the photo degradation results for the piggery waste, the Fe-containing AC/$TiO_2$ composites showed an excellent degradation activity for the chemical oxygen demand (COD) due to a photocatalysis of the supported $TiO_2$, radical reaction by Fe species and the adsorptivity and absorptivity of porous carbon.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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• pp.688-693
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• 2008

This paper presents a study on the photocatalytic reaction about the composite particles of $TiO_2$-coated phosphors under visible light irradiation. Nanocrystalline titanium dioxide layers were directly coated on the alkaline earth aluminate phosphor, $CaAl_2O_4:Eu^{2+},\;Nd^{3+}$ particles by an sol-gel processing method. The photocatalytic reaction was analyzed with the degradation of methylene blue (MB) aqueous solution under UV and visible light irradiations. $TiO_2$-coated phosphor powders showed different photocatalytic mechanism, compared with pure $TiO_2$ (P-25, Degussa). Under UV-irradiation, $TiO_2$-coated phosphor powders showed slow photocatalytic reactivity in the early stage and fast in the latter, compared with that of pure $TiO_2$. However, $TiO_2$-coated phosphor powders showed much faster photocatalytic reactivity than that of pure $TiO_2$ under visible irradiation. In addition, the characterizations of the $TiO_2$-coated phosphor powders were conducted by a X-ray diffractometer (XRD), transmission electron microscope (TEM), and energy dispersive spectroscopy (EDS).

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.25-33
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• 2015

This study aims to synthesis the self-cleaning fibers. The nano-titanium dioxide ($TiO_2$) were blend with the polypropylene (grade 561R) at 1wt%, 3wt%, 5wt%, 10wt%, 15wt% and 20wt%. The $TiO_2$-fibers were obtained from single screw extruder. The mechanical, thermal, rheology and self-cleaning properties were also investigated. The results showed that the tensile strength of the $nTiO_2$-PP fibers decreased with increasing of the amount of $TiO_2$. The presents of the $TiO_2$ in the PP fibers significantly showed the improving of the self-cleaning properties under sunlight and 20 watt of UV radiation. The $TiO_2$-PP fibers in presents of $TiO_2$ 20wt% showed the best results of self-cleaning under 5 hours of the sunlight which the similar results were found under 5 hours of 20 watts of UV radiation.