• 공업화학
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• 제23권4호
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• pp.405-408
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• 2012

이성분계 이온성액체를 사용하여 다양한 모양의 이산화티타늄 입자를 수정된 졸-겔법을 이용하여 제조하였다. 합성에 사용된 이온성액체의 종류에 따라 이산화티타늄 입자는 다양한 형태를 가지고 있었다. 이는 이온성액체와 유기용매계면 사이에서 형성되는 이산화티타늄이 두 물질 사이의 상호작용에 영향을 받아 입자의 모양이 형성되기 때문이다. 제조된 입자의 광촉매 성능을 측정하기 위하여 4-chlorophenol 분해반응을 실시하였다. 그 결과 1-Octyl-3-methylimidazolium tetrafluoroborate과 1-Octyl-3-methylimidazolium tetrafluoroborate를 이용하여 합성한 $TiO_2$ 입자가 가장 우수한 광촉매 활성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.815-820
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• 2011

Three kinds of organometallic compounds (chromium acetylacetonate, magnesium acetate and vanadyl acetylacetonate) were used as transition metal precursor, titanium n-butoxide and multi-walled carbon nanotube as titanium and carbon precursor to prepare metal oxide-CNT/$TiO^2$ composites. The surface properties and morphology of metal oxide-CNT/$TiO^2$ composites were by Brauer-Emett-Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The photocatalytic activity of prepared metal oxide-CNT/$TiO^2$ composites was determined by the degradation effect of methylene blue in an aqueous solution under irradiation of visible light.

• Korean Chemical Engineering Research
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• 제56권2호
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• pp.156-161
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• 2018

염소법과 졸-겔법으로 $TiO_2$ 광촉매 분말을 제조하였다. 제조방법 및 조건에 따라 촉매의 결정상 형태(아나타제와 루타일)와 비표면적이 변화하는 것을 알 수 있었다. TTIP-sol로 제조한 광촉매가 염소법이나 TBOT-sol로 제조한 광촉매에 비해 methylene blue (MB) 분해 특성이 더 높았으며, 수용액상의 90% 이상의 MB를 제거할 수 있었다. 실험 결과를 통해 $TiO_2$ 광촉매는 단일 아나타제상와 큰 비표면적을 가지면 유기물 분해 특성을 향상될 수 있는 것을 확인하였다.

• 한국재료학회지
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• 제28권11호
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• pp.620-626
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• 2018

Highly self-cleaning thin films of $TiO_2-SiO_2$ co-doped with Ag and F are prepared by the sol-gel method. The asprepared thin films consist of bottom $SiO_2$ and top $TiO_2$ layers which are modified by doping with F, Ag and F-Ag elements. XRD analysis confirms that the prepared thin film is a crystalline anatase phase. UV-vis spectra show that the light absorption of $Ag-F-TiO_2/SiO_2$ thin films is tuned in the visible region. The self-cleaning properties of the prepared films are evaluated by a water contact angle measurement under UV light irradiation. The photocatalytic performances of the thin films are studied using methylene blue dye under both UV and visible light irradiation. The $Ag-F-TiO_2/SiO_2$ thin films exhibit higher photocatalytic activity under both UV and visible light compared with other samples of pure $TiO_2$, Ag-doped $TiO_2$, and F-doped $TiO_2$ films.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.174-175
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• 2019

Recently, due to air pollution caused by fine dust, it is considered as a social problem. Increasing fine dust has intensified air pollution, causing many diseases and damages. This year, Seoul, South Korea, reached a severe level of fine dust pollution worldwide. The Ministry of Environment has strengthened the environmental standard for fine dust (PM2.5) from $50{\mu}g/m^3$ to $35{\mu}g/m^3$ since March 2018. When fine dust enters the human body, it causes bronchial or skin elongation such as respiratory allergies, irritable pneumonia, asthma and atopy. In this study, $TiO_2$ rutile with photocatalytic activity was used, and materials prepared by rutile sulfuric acid method were used. The photocatalytic activity rate is 95% or more and the density is $4.1g/cm^3$. The matrix was based on cement, and the substitution rate of $TiO_2$ was 0, 5, 10, 15, 20 (%). The test item is flexural strength and compressive strength.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.370.1-370.1
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• 2016

Volatile organic compounds (VOCs) are considered hazardous air pollutants and these are emitted from building materials and household products. VOCs can cause global warming as well as human sickness, and even cancer. Photocatalysis provides a way of converting VOCs into harmless materials. Various researches have shown that $TiO_2$ is the most efficient photocatalysts due to its excellent activity. In this study, metal/non-metal doped $TiO_2$ particles are synthesized for the enhancement of the photocatalytic properties of pure $TiO_2$. By metal/non-metal doping, band gap energies of prepared samples were analyzed by UV/Visible spectrophotometer. The physical and chemical properties of synthesized powder were characterized by field emission scanning electron microscope, by BET for measuring their specific surface area, and by XRD for phase identification and particle size determination. Degradation ability for p-xylene was evaluated through monitoring the concentration in a closed chamber. Relation between their properties and decomposition abilities for VOC were evaluated based on the experimental results.

• 한국전기전자재료학회논문지
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• 제34권1호
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• pp.63-67
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• 2021

In this paper, we investigated the surface properties of polymer insulators to improve electrical insulation performance. First, after washing the polymer insulator in various ways, its contact angle was increased, thereby improving the hydrophobic properties and electrical insulation properties. In addition, TiO2 thin films, which have been used as a photocatalytic material and have been applied to the polymer insulator surface of to enhance the surface and electrical insulating properties. For the sputtering method, the contact angle after coating the TiO2 thin film increased with increasing RF power, but it was lower compared to that before coating, indicating that the hydrophobic properties of the surface were slightly deteriorated. Consequently, the electrical properties of the polymer-insulating material were maintained or improved after the TiO2 thin-film coating.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6952-6957
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• 2014

광촉매 반응에서 $TiO_2$에 금속물질을 첨가하면 촉매표면이 변화되며, 이러한 금속물질은 광분해반응의 속도를 증가시킨다. 본 연구에서는 $TiO_2$ 광촉매의 광분해능력을 향상시키기 위해 다양한 방법을 이용하여 개질하였으며, 개질된 광촉매의 광분해특성은 회분식 광반응기를 이용하여 조사하였다. 우수한 $TiO_2$ 광촉매용액을 얻기 위해 여러 종류의 분산제와 안정제를 조사하였으며, 분산제로는 isoproply alcohol, 안정제로는 sodium silicate가 적합하였다. 톨루엔 분해반응을 향상시키기 위해 다양한 금속물질을 $TiO_2$ 광촉매에 첨가하여 광분해효율을 조사한 결과 Pd가 가장 우수하였으며, Cu와 W도 우수하였다. Pd를 첨가한 경우 25%의 제거효율 향상이 있었다. 그러나 Fe의 경우 광촉매분해반응을 상당히 저해하는 것으로 나타났다. $Pd/TiO_2$ 광촉매에 Cu 또는 W를 부가적으로 첨가하여도 촉매의 광분해효율에는 증가가 없었다.

• 한국분말재료학회지
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• 제24권6호
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• pp.477-482
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• 2017

Nitrogen-doped titanium dioxide (N-doped $TiO_2$) is attracting continuously increasing attention as a material for environmental photocatalysis. The N-atoms can occupy both interstitial and substitutional positions in the solid, with some evidence of a preference for interstitial sites. In this study, N-doped $TiO_2$ is prepared by the sol-gel method using $NH_4OH$ and $NH_4Cl$ as N ion doping agents, and the physical and photocatalytic properties with changes in the synthesis temperature and amount of agent are analyzed. The photocatalytic activities of the N-doped $TiO_2$ samples are evaluated based on the decomposition of methylene blue (MB) under visible-light irradiation. The addition of 5 wt% $NH_4Cl$ produces the best physical properties. As per the UV-vis analysis results, the N-doped $TiO_2$ exhibits a higher visible-light activity than the undoped $TiO_2$. The wavelength of the N-doped $TiO_2$ shifts to the visible-light region up to 412 nm. In addition, this sample shows MB removal of approximately 81%, with the whiteness increasing to +97 when the synthesis temperature is $600^{\circ}C$. The coloration and phase structure of the N-doped $TiO_2$ are characterized in detail using UV-vis, CIE Lab color parameter measurements, and powder X-ray diffraction (XRD).

• 한국재료학회지
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• 제27권6호
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• pp.325-330
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• 2017

Photoelectron-hole separation efficiency plays an important role in the enhancement of the photocatalytic activity of photocatalysts towards the degradation of organic molecules. In this study, $TiO_2/TiOF_2$ heterostructured composite powders with suitable band structures, which structures are able to separate photoelectron-hole pairs, have been synthesized using a simple and versatile ultrasonic spray pyrolysis process. In addition, their phase volume fractions have been controlled by varying the pyrolysis temperature from $400^{\circ}C$ to $800^{\circ}C$. The structural and optical properties of the synthesized powders have been characterized by X-ray diffraction, scanning electronic microscopy and UV-vis spectroscopy. The powder with a phase volume ratio close to 1, compared with single $TiOF_2$ and other composite powders with different phase volume fractions, was found to have superior photocatalytic activity for the degradation of rhodamine B. This result shows that the $TiO_2/TiOF_2$ heterostructure promotes the separation of the photoinduced electrons and holes and that this powder can be applicable to environmental cleaning applications.