• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.415-422
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• 2005

The photocatalytic decolorization of Reactive Red 2B(RR2B) was studied using immobilized photocatalyst/UV System. Two pairs of 20 W UV-B and UV-C lamps were employed as the light source. Immobilization of $TiO_2$ was carried out using sponge (as the photocatalyst body) and silicone sealant(as the binder). The effects of parameters such as the thickness, pore size of sponge photocatalyst and attached material on the reactor bottom were investigated. The results showed that the optimum thickness of sponge photocatalyst was 1 cm. Decolorization of reactor which had the bottom coated $TiO_2$ was higher than that of reactor attached aluminum plate. Decolorization of photocatalyst with large pore size(mean pore size, 3.8 mm) was higher than that of the small(mean pore size, 1.75 mm). Initial decolorization of RR2B could be descrived using the Langmuir-Hinshelwood(L-H) model and gave constant values of $0.55mg/l{\cdot}min(k)\;and\;2.65{\times}10^{-2}l/mg(K)$, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.160-160
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• 2011

In the present work, $TiO_2$ fiilms supported by porous silica gel with high surface area synthesized by atomic layer deposition(ALD). Porous structure of silica substrate could be maintained even after deposit large amount of $TiO_2$ (500 cycles of ALD process), suggesting the differential growth mode of $TiO_2$ on top surface and inside the pore. All the $TiO_2$-covered silica samples showed improved MB adsorption abilities, comparing to bare one. In addition, when silica surface was covered with $TiO_2$ films, MB adsorption capacity was almost fully recovered by re-annealing process (500$^{\circ}C$, for 1 hr, in ambient pressure), whereas MB adsorption capacity of bare silica was decreased after re-heaing process. FT-IR study demonstrated that $TiO_2$ film could prevent deposition of surface-bound intermediate species during thermal decomposition of adsorbed MB molecules. Photocatalytic activity of $TiO_2$/silica sample was also investigated.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.274-276
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• 2005

본 논문에서는 유동층 화학기상증착법(FB CVB; Fluidized Bed Chemical Vapor Deposition)으로 광촉매가 박막증착된 비드를 제조하였고 제조된 광촉매코팅비드의 광반응성을 연속식 반응기에서 아세트알데히드의 분해능력을 측정하여 분석하였다. 광촉매가 박막증착된 비드의 FE-SEM 분석 결과 글라스 비드 위의 티타니아는 비교적 매끄럽게 증착되었고, 실리카 위의 티타니아는 입자의 형태로 증착되었으며 알루미나 위의 티타니아는 결정상을 이루며 증착됨을 확인 할 수 있었다. Acetaldehyde 기체의 광촉매에 의한 분해 실험을 진행하기 위해 연속식 반응기를 설계 제작하였고, 이 반응기를 사용하여 제조된 광촉매 코팅입자의 광반응성을 살펴보았다. 반응기는 가스 주입구와 출구를 갖고 있으며, 중심부에 UV 램프가 설치되었다. 반응기는 내열유리(pyrex)로 제작하였으며, 체적은 100 ml이다. 반응기 내부의 중심부에 UV 램프가 설치되고 UV 램프와 반응기 외부사이에 유동층 화학기상증착법에 의해 티타니아가 박막증착된 광촉매입자가 위치하여 광반응성을 평가하였다. 유량변화에 따른 광반응성을 측정하였으며, 알루미나에 광촉매를 증착시킨 제품의 경우 가스유량 100cc/min에서는 acetaldehyde가 $100\%$ 분해되고, 가스유량 500cc/min에서는 $50\%$정도 분해되는 것을 알 수 있었다.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.40-45
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• 2007

Methylene blue(MB) was photocatalytically degraded with one-body photoanode and solar simulator to investigate the possible application to both environmental purification and photoelectrochemical cell for hydrogen production. Photoactive titanium dioxide was formed on both sides of Ti plate following steps such as rinsing-annealing-calcination or anodizing(20 V, 30 V)-annealing($350^{\circ}C$, $450^{\circ}C)$ after etching. The prepared titania plate($2cm{\times}2\;cm$, ca 1.6 mg $TiO_2$ on the basis of $1\;{\mu}m$ thickness) was used to degrade MB(10 ppm in 200 mL solution). The reaction tended to follow the Langmuir-Hinshelwood kinetics with zero order. Comparative experiments with Degussa P25 showed the same zero order kinetics when 2 mg of P25 had been used, while the first order kinetics when 200 mg used. This concludes the feasibility of the prepared titania plate as a material for the purification of low-level harmful organics and an electrode or a membrane for photoelectrochemical system for hydrogen production.

• Journal of Ocean Engineering and Technology
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• v.17 no.3 s.52
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• pp.52-56
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• 2003

This study investigates the photoelectrochemical behavior of STS304 steel with TiO2 thin films coating, applied by sol-gel mehod, for the purpose of cathodic photoprotection of the steel corrosion. One time TiO2-coated STS304 steel, adapted with two kinds of TiO2 sol solution, has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40 W fluorescent lamp, respectively. That had yielded more negative values than the corrosion potential of the bare metal(-130mv vs.SCE). The bleaching of TCE was confirmed on TiO2-coated STS304 steel under UV-illumination with 20W Black-light. This Study concluded that Ti02-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and a photocatalytic self-cleaning effect.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.153-154
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• 2018

As the air pollution progresses, the pollution degree of the indoor air quality is increased, and when the pollution degree of the indoor air quality is increased, it causes respiratory diseases and skin diseases. In addition, volatile organic compounds are released from the materials used for architectural interior decoration, and volatile organic compounds are the main cause of polluting indoor air quality. In order to improve indoor air quality, we tried to secure indoor air quality pollution by using photocatalyst which has the function of decomposing harmful substances. photocatalyst is a material that promotes chemical reaction by absorbing light. The photocatalyst used in the experiment was TiO₂, In this study, an adsorption type hardener for reducing volatile organic compounds was prepared by photocatalytic reaction. the formaldehyde and CO₂ concentrations of the cured products were analyzed according to the TiO₂ content.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.307-311
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• 2002

This study was investigated the photoelectrochemical behavior of STS304 steel with $TiO_2$ thin films coating, applied by sol-gel method, for the purpose of cathodic photoprotection of the steel corrosion. One time $TiO_2$-coated STS304 steel adopted two kinds of $TiO_2$ sol solution has the most dominant photopotential abilities, which was -200mV vs. SCE and -500mV vs. SCE under illumination with 40W fluorescent lamp, respectively. That was more negative than the corrosion potential of the bare metal(-150 mV). The bleaching of TCE was confirmed on $TiO_2$-coated STS304 under UV-illumination with 20 W Black-light. This Study was concluded that $TiO_2$-coated STS304 exhibited both a cathodic photoprotection effect against corrosion and photocatalytic self-cleaning effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.284-284
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• 2010

Currently, hydrogen has been produced by Steam Reforming or partial oxidation reforming processes mainly from oil, coal, and natural gas and results in the production of $CO_2$. However, these are influenced greatly on the green house effect of the earth. so it is important to find the new way to produce hydrogen utilizing water without producing any environmentally harmful by-products. In our research, we use microwave water plasma and photocatalyst to improve dissociation rate of water. At low pressure plasma, electron have high energy but density is low, so temperature of reactor is low. This may cause of recombination in the generated hydrogen and oxygen from splitting water. If it want to high dissociation rate of water, it is necessary to control of recombination of the hydrogen and oxygen using photocatalyst. We utilize the photocatalytic material($TiO_2$, ZnO) coated plasma reactor to use UV in the plasma. The quantity of hydrogen generated was measured by a Residual Gas Analyzer.

• Advances in nano research
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• v.10 no.3
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• pp.211-219
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• 2021

The evaluation of the corrosion resistance of titanium with a TiO2 nanotubes top layer was carried out (TiO2 NT). These nanostructures were evolved into anatase nanoparticles without heat treatment in an aqueous medium, which is a novel phenomenon. This work analyzes the layer between the nanotube bottom and the substrate, which is thin and still susceptible to corrosion. The bottom of TiO2 nanotubes having Fluor resulting from the synthesis process changed between amorphous to crystalline anatase with a crystallite size of about 4 nm, which influenced the corrosion rates. Four kinds of samples were evaluated. A) NT by Ti anodizing; B) NTSB for Ti plates, either modifying its surface or anodizing the modified surface; C) NT-480 for anodized Ti and heat-treated (480℃) for reaching the anatase phase; D) NTSB-480 for Ti plates, first, modifying its surface using sandblast, after that, anodizing the modified surface, and finally, heat-treated to 480℃ to compare with samples having induced crystallization and passivation. Four electrochemical techniques were used to evaluate the corrosion rates. The surfaces having TiO2 nanotubes with a sandblast pre-treatment had the highest resistance to corrosion.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.424-424
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• 2008

Dye-sensitized Solar Cell (DSC) is a new type of solar cell by using photocatalytic properties of $TiO_2$. The electric potential distribution in DSCs has played a major role in the operation of such cells. Models based on a built-in electric field which sets the upper limit for the open circuit voltage(Voc) and/or the possibility of a Schottky barrier at the interface between the mesoporous wide band gap semiconductor and the transparent conducting substrate have been presented. $TiO_2$ thin films were deposited on the FTO substrate by Nd:YAG Pulsed Laser Deposition(PLD) at room temperature and post-deposition annealing at $500^{\circ}C$ in flowing $O_2$ atmosphere for 1 hour. The structural properties of $TiO_2$ thin films have investigated by X-ray diffraction(XRD) and atomic force microscope(AFM). Thickness of $TiO_2$ thin films were controlled deference deposition time and measurement by scanning electron microscope(SEM). Then we manufactured a DSC unit cells and I-V and efficiency were tested using solar simulator.