• 한국재료학회지
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• 제11권7호
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• pp.537-544
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• 2001

$TiO_2$광촉매릉 반응성 스퍼터링법을 이웅하여 박막으로 제조하고 유기물 및 살균실험을 통하여 미세조직이 광촉매 효율에 미치는 영향을 조사하고자 하였다. 광촉매 효율측정을 위하여 페놀분해실험 및 E.coli 078을 이용한 살균실험을 행하였다. $TiO_2$박막에 의한 페놀분해실험 시, 전자수용체인 산소의 공급에 의하여 분해효율이 2배까지 증가하였다. E.coli 078분해실험의 경우, 광촉매 $TiO_2$박막을 사웅하여 살균하였을때 UV만 조사하여 살균하였을 경우 보다 분해효율이 최고 70% 이상 증가하였다. 페놀분해실험과 E.coli 078 살균실험 결과 저결정성 박막의 경우 분해능이 매우 미약하였으며, 표면조도가 높고 결정성이 우수한 박막의 경우에 높은 광촉매 효율을 나타내어$TiO_2$박막의 광촉매 효과는 표면형상과 결정성이 매우 중요한 인자로 작용하였다.

• 한국재료학회지
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• 제17권11호
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• pp.593-600
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• 2007

Aluminum was anodized in a $H_2SO_4$ solution, and titanium (IV) oxide ($TiO_2$) was electrodeposited into nanopores of anodic porous alumina in a mixed solution of $TiOSO_4$ and $(COOH)_2$. The photocatalytic activity of the prepared film was analyzed for photodegradation of methylene blue aqueous solution. Consequently, we found it was possible to electrodeposit $TiO_2$ onto anodic porous alumina, and synthesized it into the nanopores by hydrolysis of a titanium complex ion under AC 8-9 V when film thickness was about $15-20{\mu}m$. The photocatalytic activity of $TiO_2$-loaded anodic porous alumina ($TiO_2/Al_2O_3$) at an impressed voltage of 9 V was the highest in every condition, being about 12 times as high as sol-gel $TiO_2$ on anodic porous alumina. The results revealed that anodic porous alumina is effective as a substrate for photocatalytic film and that high-activity $TiO_2$ film can be prepared at low cost.

• Environmental Engineering Research
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• 제13권3호
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• pp.136-140
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• 2008

$TiO_2$ photocatalyst has been known to exhibit a notable disinfecting activity against a broad spectrum of microorganisms. A lot of commercial $TiO_2$ photocatalyst products have been developed for antimicrobial purposes. However, a standard method has not yet been proposed for use in testing antimicrobial activity. In this study, we developed a $TiO_2$ photocatalytic adhesion test method with film as the standard testing method for the evaluation of antimicrobial activity. This method was devised by modifying the previous antimicrobial products test method, which has been widely used, and considering the characteristics of $TiO_2$ photocatalytic reaction. The apparatus for testing the antimicrobial activity was composed of a Black Light Blue (BLB) lamp as UV-A light source, a Petri dish as the cover material, and a polypropylene film as the adhesion film. The standard $TiO_2$ photocatalyst sample, Degussa P25 $TiO_2$ - coated glass, could only be used once. The optimal initial concentration of the microorganism, proper light intensity, and light irradiation time were determined to be $10^6$ CFU/mL, 1.0 mW/$cm^2$, and 3 hr, respectively, for testing and evaluating antimicrobial activity on the $TiO_2$ surface.

• 멤브레인
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• 제27권4호
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• pp.328-335
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• 2017

메조포러스 공극구조를 갖는 광촉매 멤브레인은 다양한 환경기술에 적용될 수 있다. 본 연구에서는 $TiO_2$ 층을 형성시킨 광촉매 반응기용 세라믹 멤브레인을 개발하고 이를 염색용액 처리에 적용하였다. 높은 공극률과 균질성을 지닌 $TiO_2$ 광촉매층을 그라프트 공중합체를 사용하여 제조하였다. 멤브레인은 광촉매 반응기와 멤브레인 여과를 결합시킨 하이브리드 광촉매 반응기에 성공적으로 적용하였다. 실험결과 정렬된 구조의 $TiO_2$ 층이 $Al_2O_3$ 지지체에 형성되었다. $TiO_2$ 층 형성 후 제조된 세라믹 분리막의 순수 투과도는 형성된 광촉매 층 저항으로 감소하였다. 정렬된 구조의 $TiO_2$ 층은 UV 결합 시 5시간 안에 완벽한 염색용액 분해를 달성시킬 수 있었다. 광촉매 멤브레인의 염색용액 분해는 Langmuir-Hinshelwood 흡착 모델로 잘 설명할 수 있었다. 또한 $TiO_2$ 층이 고정화된 세라믹 멤브레인의 model Congo Red에 대한 1차 속도상수는 $Al_2O_3$ 지지체 단독인 경우에 비해 약 6배 정도 큰 값을 나타내었다(0.0081 vs. $0.0013min^{-1}$).

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권2호
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• pp.8-14
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• 2016

We compared the plausible reaction mechanism and quantitative efficiency of highly self-organized TiO₂ nanotube (ntTiO₂) film with TiO₂ powder. Film was fabricated by electrochemical potentiostatic anodization of titanium thin film in an ethylene-glycol electrolyte solution containing 0.3 wt% NH₄F and 2 vol% deionized water. Nanotubes with a pore size of 80-100 nm were formed by anodization at 60 V for 3 h. Humic acid (HA) was degraded through photocatalytic degradation using the ntTiO₂ film. Pseudo first-order rate constants for 0.3 g of ntTiO₂, 0.3 g TiO₂ powder, and 1 g TiO₂ powder were 0.081 min⁻¹, 0.003 min⁻¹, and 0.044 min⁻¹, respectively. HA adsorption on the ntTiO₂ film was minimal while adsorption on the TiO₂ powder was about 20% based on thermogravimetric analysis. Approximately five-fold more normalized OH radicals were generated by the ntTiO₂ film than the TiO₂ powder. These quantitative findings explain why ntTiO₂ film showed superior photocatalytic performance to TiO₂ powder.

• 청정기술
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• 제27권3호
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• pp.217-222
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• 2021

Although monolayer black phosphorus (BP) and few-layer BP nanosheets (NSs) have been extensively studied as promising alternatives to graphene, research has focused primarily on atomically thin-layered BP in an isolated form. In order to realize the practical applications of BP-related devices, a BP film based on continuous networking of few-layer BP NSs should be developed. In this study, a transparent BP film with high quality was fabricated via a vacuum filtration method. An oxygen-free water solvent was used as an exfoliation medium to avoid significant oxidation of the few-layer BP NSs in liquid-phase exfoliation. The exfoliation efficiency from bulk BP to the few-layer BP NSs was estimated at 22%, which is highly efficient for the production of continuous BP film. The characteristics of the high-quality BP film were determined as 98% transparency, minimum oxidation of 18%, structural stability, and an appropriate bandgap of about 1.8 eV as a semiconductor layer. In order to demonstrate the potential of the BP film for photocatalytic activity, we performed photoelectrochemical water oxidation of the transparent BP film. Although its performance should be improved for practical applications, the BP film could function as a photoanode, which offers a new potential semiconductor in water oxidation. We believe that if the BP film is adequately engineered with other catalysts the photocatalytic activity of the BP film will be improved.

• 산업기술연구
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• 제17권
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• pp.249-254
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• 1997

Photocatalytic reaction using $TiO_2$ thin film was applied for the inactivation of coliform bacteria and the degradation of formic acid. UV processes coupled with and without $TiO_2$ were tested for the river water samples. It took 5 and 15 minutes, respectively, to obtain 99% destruction of coliform bacteria in the total coliform test, which demonstrated the effectiveness of the photocatalytic reaction. Complete degradation of formic acid determined by TOC analysis was observed in 20 minutes by ozone/photocatalysis, while formic acid was degraded as little as about 20% during the first 100 minutes by ozone treatment alone. When ozone was supplied to the $TiO_2/UV$ system, however, it provided a synergetic effect for the degradation of formic acid.

• Environmental Engineering Research
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• 제7권4호
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• pp.227-237
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• 2002

Chemical vapor deposition (CVD), ion beam sputtering (IBS) and sol-gel method were used to prepare TiO$_2$ thin films for degradation of hazardous organic compounds exemplified by 2-chlorophenol (2-CP). The influence of supporting materials and coating methods on the photocatalytic activity of the TiO$_2$ thin films were also studied. TiO$_2$ thin films were coated onto various supporting materials including steel cloth (SS), copper cloth, quartz glass tube (QGT), and silica gel (SG). Results indicate that SS (37 μm)- TiO$_2$ thin film prepared by IBS method improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 μm) is found to be the best support.

• 한국태양에너지학회 논문집
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• 제22권3호
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• pp.57-65
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• 2002

The photocatalytic degradation of TCE using solar energy in POFR was studied. The use of solar energy was investigated in plastic optica fiber photocatalytic reactor (POFR). In POFR, the main parameters of photocatalytic degradation of TCE were lihgt intensity, thickness of $TiO_2$-coated film on plastic fiber core, the same of total $TiO_2$-coated surface area with changed length. We studied the apparent photonic efficiency and photocatalytic degradation rate of TCE in POFR. The apparent photonic efficiency of various light intensities was decreased by an incresed intensities. The photocatalytic activities of $TiO_2$-coated optical fiber reactor system depended on the coating thickness, and total clad-stripped surface area of POF. Photocatalytic degradation of trichloroethylene ($C_2HCl_3$, TCE) in the gas-phase was elucidated by using $TiO_2$-coated plastic optical fiber reactor. In TCE degradation, in-situ FTIR measurement resulted in mineralization into $CO_2$.

• 한국재료학회지
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• 제27권11호
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• pp.577-582
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• 2017

Self-cleaning and photocatalytic $TiO_2$ thin films were prepared by a facile sol-gel method followed by spin coating using peroxo titanic acid as a precursor. The as-prepared thin films were heated at low temperature($110^{\circ}C$) and high temperature ($400^{\circ}C$). Thin films were characterized by X-ray diffraction(XRD), Field-emission scanning electron microscopy(FESEM), UV-Visible spectroscopy and water contact angle measurement. XRD analysis confirms the low crystallinity of thin films prepared at low temperature, while crystalline anatase phase was found the for high temperature thin film. The photocatalytic activity of thin films was studied by the photocatalytic degradation of methylene blue dye solution. Self-cleaning and photocatalytic performance of both low and high temperature thin films were compared.