• Journal of the Korean Chemical Society
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• v.57 no.4
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• pp.483-488
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• 2013

Copper oxide (CuO) was synthesized from $CuCl_2$ by solution method. Anatase $TiO_2$ particle was dispersed into the solution before preparing CuO, so that $TiO_2$/CuO heterojunction was created through the nucleation of CuO onto the $TiO_2$ surface. Some amount of CuO was reduced to $Cu_2O$ by treating glucose into the solution, thereby preparing $TiO_2/Cu_xO$ complex. The obtained $TiO_2/Cu_xO$ complex showed advanced phtocatalytic activity under the sun light compared with the P-25 sample. In addition, the the $TiO_2/Cu_xO$ complex showed excellent antipathogenic effect.

• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.560-564
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• 2009

ZnO and Mn-substituted $Zn_{0.95}Mn_{0.05}O$ were synthesized by using precipitation method. $Zn_{0.95}Mn_{0.05}O$ compound absorbed UV light as well as hole range of visible light ($400{\sim}800$ nm). Results obtained revealed that $Zn_{0.95}Mn_{0.05}O$ showed higher activity than P-25 for visible-photocatalytic degradation of 1,4- dichlorobenzene.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.83-86
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• 2007

가시광에서 활성을 보이는 $TiO_2$광촉매를 이용하여 대표적인 방향족 VOCs인 BTEX의 분해효과에 대한 실험을 실시하였다. 실험 결과 Xylene은 높은 전환율을 나타낸 반면, Benzene은 가장 낮은 전환율을 나타냈다. 이는 Benzene이 다른 물질에 비해 상대적으로 안정적인 분자 구조에 의해서 반응성이 매우 약하기 때문인 것으로 사료된다. 본 실험은 여러 가지 조건들 중에 농도와 유량만 변화 시킨 가운데 얻어진 결과이기 때문에 향후 연구에서 습도, 농도, 유량 및 빛의 강도 등 다양한 조건의 변화에 따라 최적의 조건을 찾아낼 수 있을 것으로 판단된다. S 가 도핑된 $TiO_2$ 광촉매는 가시광 하에서 방향족 VOCs를 제어하는 광촉매 기술 중에 비교적 최신의 기술이며, 향후의 연구 개발이 더욱 필요하다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1579-1582
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• 2007

The purpose of this study is to compare degrading performance of organic contaminants in aqueous solution using photocatalyst and find an optimal condition for decomposing non-degradable matters. The parameters of this research is light intensity and state of photocatalytic material within reactor. The results showed that Type 3 (terms of plastic beads : $500^{\circ}C$, 3hr) has the greatest reactivity.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.308-312
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• 2012

Nitrogen doped $TiO_2$ photocatalysts were prepared by ammonia for exploring the visible light photocatalytic activity. To explore the visible light photocatalytic activity of the nitrogen doped $TiO_2$ photocatalyst, the removal of methylene blue dye was investigated under the sunlight. SEM images showed that the flocculated particle sizes of N-doped $TiO_2$ decreased due to the reaction with ammonia. XRD patterns demonstrated that the samples calcined at temperatures up to $600^{\circ}C$ and doped with nitrogen using ammonia clearly showed rutile as well as anatase peaks. The XPS results showed that the nitrogen composition onto $TiO_2$ increased according to the reaction time with ammonia. Photocatalytic activity of the nitrogen doped $TiO_2$ was better than that of undoped $TiO_2$. Nitrogen doping onto the $TiO_2$ also affected the crystal type of $TiO_2$ photocatalyst.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3031-3038
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• 2009

Cobalt-loaded activated carbon fibers (ACFs) supported titanium dioxide ($TiO_2$) photocatalyst was developed by sol-gel method. The Co-ACFs/$TiO_2$ photocatalyst were characterized by scanning electron microscope (SEM), X.ray diffraction patterns (XRD), energy dispersive X.ray analysis (EDX) and UV-vis absorption spectroscopy. Decomposition efficiency of methylene blue (MB) solution by Co-ACFs/$TiO_2$ photocatalyst reached almost 100% under 300 min reaction. The MB molecules in the bulk solutions were supposed to be condensed around $TiO_2$ particles by adsorption of ACFs. Therefore, the photocatalyst possesses the combined effect of adsorption by activated carbon fibers and photocatalytic reactivity of $TiO_2$ on MB degradation. Due to the cobalt has electron transition effece, thus improved the photodegradation of MB solution.

• Applied Chemistry for Engineering
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• v.19 no.6
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• pp.674-679
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• 2008

$TiO_2$ impregnated stainless steel fiber photocatalysts ($TiO_2/SSF$) were fabricated to overcome inherent problems of powdery $TiO_2$ photocatalysts in water treatment. Adhesion strength of the impregnated $TiO_2$ was examined using an ultrasonic-cleaner. Photocatalytic activity was evaluated through decomposition experiment of methylene blue and formic acid. Bactericidal efficiency was evaluated through sterilization experiment of E. Coli and Vibrio Vulnificus. Adhesion strength of the impregnated $TiO_2$ was so high that more than 95% was left over even after the treatment in an ultrasonic-cleaner for 30 min. Methylene blue and formic acid were decomposed as much as 60% and 38% of the initial concentration and more than 99.9% of E. Coli and Vibrio Vulnificus were killed after 1 hour exposure to the prepared photocatalyst under UV irradiation. In the case of decomposition of formic acid, decomposition ratio increased if oxidants were added. Especially the decomposition ratio increased as high as 80% when hydrogen peroxide was added as an oxidant.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.195-202
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• 2013

$TiO_2$ powders were prepared from titanium (IV) sulfate ($Ti(SO_4)_2$) solution using ammonia solution at low reaction temperature ($80{\sim}100^{\circ}C$) and atmospheric pressure by hydrothermal precipitation method without calcination. The effect of reaction conditions, such as reaction temperature, initial concentration of titanium (IV) sulfate ($Ti(SO_4)_2$) solution, pH of mixture solution and the physical properties of the prepared $TiO_2$, such as crystallite structure, crystallite size were investigated. The photocatalytic activity of prepared $TiO_2$ was tested by the photolysis of brilliant blue FCF (BB-FCF) under the UV and the analysis of UV-VIS diffuse reflectance spectroscopy (DRS). The physical properties of prepared $TiO_2$ were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectrometer (PL), particle size distribution measurements. The crystallite size and crystallinity of prepared $TiO_2$ increased with increasing titanium (IV) sulfate ($Ti(SO_4)_2$) concentration, but photocatalytic activity decreased. The crystallite size decreased with increasing pH of mixture solution, but photocatalytic activity increased. The crystallinity and photocatalytic activity increased with increasing reaction temperature. The results showed that anatase type $TiO_2$ could be prepared by hydrothermal precipitation method using titanium (IV) sulfate ($Ti(SO_4)_2$) solution and ammonia solution at low reaction temperature and atmospheric pressure without calcination.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.56-61
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• 2005

Highly durable photocatalytic paper containing anatase $TiO_{2}$, active carbon and ceramic fiber, which can adsorb VOCs and decompose them by photo oxidation simultaneously, was manufactured and characterized. Optimum concentration of PDADMAC to let $TiO_{2}$ adhere on the surfaces of active carbon and ceramic fiber selectively was $10\~15$ ppm in a slurry mixture for making photocatalytic paper. The thickness and basis weight of the produced catalytic paper by paper-making method were 0.4 mm and 380 $g/m^{2}$, respectively. Adsorption reaction by active carbon and photocatalytic decomposition reaction by $TiO_{2}$ were proceeded simultaneously, by which the abatement rate was found to be greatly enhanced compared to the similar environment with single adsorption reaction or single photocatalytic reaction only. The selective attachment of $TiO_{2}$ on ceramic fiber and active carbon was found to be very effective in preventing decomposition of substrate by the $TiO_{2}$ attack during exposure to UV light.

• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.331-337
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• 2019

Titania has become the most applicable material for photocatalytic application. Nevertheless, titania has the weak point in its wide band gap energy that is mainly activated by UV irradiation. There have been vast research challenges in order to make the wide band gap energy of titania narrow that could be activated in the presence of visible light. Various modifications of titania surface were popular because titania needs to change its surface to respond in visible light. Among the methodological approaches, N-doping to titania can be the alternative candidate because it is facile process and eco-friendly. The activated electron from valence band in N-doped $TiO_2$ migrates to conduction band in the presence of visible light irradiation, which shows photocatalytic activity as well. In this study, focused on the evaluation of nitrogen state after N-doping through brief review. Arguments are still existed in nitrogen states and their different effects on photocatalytic activity. In particular, two nitrogen states are generally reported; substitutional and interstitial states. The research articles regarding N-doped $TiO_2$ are continuously appearing because the potential application of water split in visible light is still fascinate. The future of N-doped $TiO_2$ is also presented by referrals based on various literature.