• 한국세라믹학회지
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• 제40권9호
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• pp.902-908
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• 2003

Au/TiO$_2$ core-shell 구조 나노 미립자가 졸-겔법에 의해서 제조되었고, TiO$_2$ shell의 형상과 결정성이 TEM과 UV-Vis. absorption spectrometer에 의해서 조사되었다. Au/TiO$_2$ core-shell 나노 미립자는 Au 콜로이드 에탄올 수용액 중에서 TOAA(Titanium Oxide Acethylacetonate)의 가수분해에 의해 합성될 수 있었다. Au 나노 미립자의 표면에 형성된 TiO$_2$ shell의 두께는 약 1 nm이었다. TiO$_2$ shell의 결정성을 조사하기 위하여. TiO$_2$가 피복된 Au 콜로이드 에탄올 용액에 254 nm의 자외선과 $^{60}$Co의 방사선을 조사하였다. Au 나노 미립자의 surface plasmon 현상은 방사선이 조사되었을 때만 나타났고, 이 결과로부터 TiO$_2$ shell은 비정질 상태임을 알 수 있었으며, Au의 분산성 향상을 위해 표면에 처리된 MUA(Mercaptoundecanoic Acid)층은 전자의 이동을 방해하는 장애물로 작용하지 않음을 확인할 수 있었다.

• 한국결정성장학회지
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• 제12권2호
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• pp.110-114
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• 2002

HBPCA를 유기질 공해물질의 모델로서 선정하고 $TiO_2$에 흡착시켜서 흡착된 분자의 배향성과 광분해 생성물의 관계에 대하여 조사하였다. 용액의 pH를 변화시켜서 UV광을 조사한 뒤 생성된 광분해 생성물을 UIF와 Raman 분광기로 스펙트럼을 얻어 분석 비교하였다. 용액의 pH는 흡착된 분자의 배향에 영향을 미쳐서 광분해 생성물이 달라지며, 흡착된 분자의 배향과 광분해 생성물과의 관계는 아주 밀접하게 관련되어 있음을 확인하였다.

• 한국환경보건학회지
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• 제28권5호
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• pp.59-64
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• 2002

The photocatalytic decolorization of the Rhodamine B (RhB) was studied using a UV/TiO$_2$ reactor. Yakuri titanium dioxide(anatase) was used as the suspended photocatalyst and proved to be effective for decolorization irradiated with UV light (254 mm). The photocatalyzed dioxide concentrations, light intensity and air flow rates. In 0.01 mM RhB, color could be completely photodegraded after 3 hours. Absorption spectrum of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the solution bulk : concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the break up of the chromopore. The optimum loaded titanium dioxide for the decolorization was 0.75 g/(equation omitted). The light intensity showed exponential decay with distance. The decay of light intensity of RhB solution showed different tendency from TiO$_2$. These results suggested that the photocatalytic decolorization of dyes may be available method for decolorizing in wastewater.

• 한국환경보건학회지
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• 제29권1호
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• pp.51-61
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• 2003

Pollution purification using titanium dioxide (TiO$_2$) photocatalyst has attracted a great deal of attention with increasing number of relent environmental problems. Currently, the application of TiO$_2$ photocatalyst has been focused on purification and treatment of waste water. However. the use of conventional TiO$_2$ powder photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we herein studied the pilot-scale design to aid in optimization of the energy-saving process for more through development and reactor design by solar light/UV lamp/ TiO$_2$system. In this study, we manufactured the TiO$_2$sol by sol-gel method. According to analysis by XRD, SEM and TEM, characterization of TiO$_2$ sol were nano-size (5-6 nm) and anatase type. Inorganic binder (SiO$_2$) was added to TiO$_2$ lot to be coated for support strongly, and support of ceramic bead was used to lower separation rate that of glass bead The influences were studied of various experimental parameters such as TiO$_2$ quantity, pH, flow rate. additives, pollutants concentration, climate condition and reflection plate by means of reaction time of the main chararteristics of the obtained materials. In water treatment system, variable realtor as solar light/ or UV lamp according to climate condition such as sunny and cloudy days treated the phenol and E-coli(Escherichia coli) effectively.

• 공업화학
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• 제24권3호
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• pp.231-238
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• 2013

본 연구에서 제조한 나노구형체 $TiO_2$는 자외선 차단 효과가 우수하면서도 노폐물 흡착을 하는 기능을 부여하기 위해 Sol-gel 방법으로 합성하였다. 다공성의 특성으로 높은 표면적에 의한 우수한 자외선 차단효과 및 흡착능력을 얻기 위해 pH를 조절하였다. 염기 처리한 $TiO_2$의 경우 가장 우수한 특성을 나타내었다. TGA로 글리세린을 흡착한 결과 1.16 mg의 높은 흡착 결과를 얻을 수 있었다. 또한 UV-A 영역에서 높은 반사율을 가지는 것을 확인하였다. 무기분체의 최적의 분산제를 찾기 위해 ester oil과 silicon oil를 사용하여 입도크기를 측정하였으며 180 nm정도의 입자로 약 6개월간 유지되었다. 이 결과를 통해, UV-A영역에서 우수한 능력을 가진 자외선 차단제로서 노폐물 흡착능력을 가진 $TiO_2$를 제조했으며 이로 인한 다양한 응용이 가능할 것으로 기대된다.

• 한국응용과학기술학회지
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• 제23권2호
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• pp.153-159
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• 2006

The photocatalytic degradation of methylene blue(MB) was investigated using $TiO_2$ as photocatalyst and UV radiation. $TiO_2$ supported with activated carbon(AC) was prepared by SOL-GEL method and depended on several parameters such as the mass ratio of $TiO_2/AC$, pH and experimental time. The presence of the anatase and rutile crystal phase was determined by XRD analyses of the prepared $TiO_2$. The degradation of MB with $TiO_2/AC$ was about 20% higher than that of AC alone. A variation of photodegradation was negligible under UV radiation conditions ( ${\geq}$ 40W). It was experimentally showed that the photodegradation rate was increased with increasing the amount of photocatalyst. The optimal catalyst was prepared by impregmation of $5wt%-TiO_2$ with AC and was calcined at $300^{\circ}C$, and showed about 99% removal efficiency for 3hrs.

• 한국물환경학회지
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• 제16권4호
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• pp.445-457
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• 2000

This study was carried out comparing with ozone oxidation and photocatalytic degradation for removal of geosmin. In the change of pH, Ozonation, UV-Germicidal lamp and Halogen lamp irradiation and Halogen $lamp/TiO_2$ Powder was very slowly changing, but UV-Germicidal $lamp/TiO_2$ Powder was rapidly changed from 7.0 to 7.7 until 300min of irradiation time, and varied a little after. Geosmin degradation ratio was as following, UV-Germicidal $lamp/TiO_2$ $Powder(200mg/L){\geq}O_3$ > UV-Germicidal $lamp/TiO_2$ $Pw(100mg/L)$ > UV-Germicidal lamp > Halogen lamp. The result of investigation of generated by-products were 3-Heptanone, two sort of aldehydes and three sort of alcohols by ozonation. But It was not generated by photocatalytic degradation.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.925-928
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• 2010

Nitrogen-doped $TiO_2$ ($TiO_2$:N) nano-particles with a pure anatase crystalline structure were successfully synthesized through the hydrolysis of $TiCl_4$ in an ammonia aqueous solution. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), $N_2$-sorption, and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. The absorption edge of nitrogen-doped $TiO_2$ shifted into the visible wavelength region. The photoelectrochemical (PEC) performances were investigated for the $TiO_2$ mesoporous electrodes doped with different nitrogen concentrations. The $TiO_2$:N electrodes exhibited much higher PEC responses compared to the pure $TiO_2$ electrode because of the significantly enhanced visible-photoresponsibility of the $TiO_2$:N electrodes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.511-511
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• 2007

Low-emissivity (low-e) coatings with visible transparency have attracted increased interest m reducing heat radiation loss through window panes from ecological and sustainable aspects. $TiO_2$-silver transparent thin films for low-e have good properties for UV and IR blocking as well as photocatalyst compared to that with commercial UV blocking films such as fluorine doped oxide (FTO), antimony doped tin oxide (ATO), etc. In this study, transparent $TiO_2$-silver thin films were prepared by successive ink-jet printing of commercial nano silver and $TiO_2$ sol. The $TiO_2$ sol, as ink for ink-jet printing, were synthesized by hydrothermal process in the autoclave externally pressurized with $N_2$ gas of 200 bar at $120^{\circ}C$ for 10 hrs. The synthesized $TiO_2$ sols were all formed with brookite phase and their particle size was several to 30 nm. At first nano sized silver sol was coated on glass substrate, after that $TiO_2$ sol was coated by ink-jet printing. With increasing coating thickness of $TiO_2$-silver multilayer by repeated ink-jet coating, the absorbance of UV region (under 400nm) and IR region (over 700nm) also increase reasonably, compared to that with commercial UV blocking films.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2001년도 가을 학술발표회 발표논문집
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• pp.82-83
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• 2001

LAS(Linear Alkylbenzene sulfonate)를 $TiO_2$ 광촉매를 사용하여 분해시켰을 때 실험조건에 변화를 주어 반응시간에 따른 제거효율을 비교하는 실험을 수행하였다. pH 변화에 의해서는 산성과 중성 영역이 알카리성 영역에 비해 제거효율이 우수하였으며, 파장영역은 254nm > 312nm > 365nm의 순서로 나타났다. UV/$TiO_2$ 공정과 UV/$TiO_2$$H_2O_2$공정을 비교해보면 $H_2O_2$의 첨가에 의한 제거효율이 다소 우수함을 알 수 있었다.