• 제목/요약/키워드: photocatalytic $TiO_2$

검색결과 795건 처리시간 0.024초

Synthesis and characterization Au doped TiO2 film for photocatalytic function

  • Son, Jeong-Hun;Bae, Byung-Seo;Bae, Dong-Sik
    • 한국결정성장학회지
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    • 제25권6호
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    • pp.280-284
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    • 2015
  • Au doped $TiO_2$ nanoparticles have been synthesized using a reverse micelle technique combined with metal alkoxide hydrolysis and condensation. Au doped $TiO_2$ was coated with glass substrate. The size of the particles and thickness of the coating can be controlled by manipulating the relative rates of the hydrolysis and condensation reaction of TTIP within the micro-emulsion. The average size of synthesized Au doped $TiO_2$ nanoparticle was about in the size range of 15 to 25 nm and the Au particles formed mainly the range of 2 to 10 nm in diameter. The effect of synthesis parameters, such as the molar ratio of water to TTIP and the molar ratio of water to surfactant, are discussed. The synthesized nanopaticles were coated on glass substrate by a spin coating process. The thickness of thin film was about 80 nm. The degradation of MB on a $TiO_2$ thin film was enhanced over 20 % efficiency by the incorporation of Au.

Tunable Nanostructure of TiO2/Reduced Graphene Oxide Composite for High Photocatalysis

  • He, Di;Li, Yongli;Wang, Jinshu;Yang, Yilong;An, Qier
    • Applied Microscopy
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    • 제46권1호
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    • pp.37-44
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    • 2016
  • In this study $TiO_2$/reduced graphene oxide ($TiO_2/rGO$) bipyramid with tunable nanostructure was fabricated by two-step solvothermal process and subsequent heat-treatment in air. The as-synthesized anatase $TiO_2$ nanocrystals possessed morphological bipyramid with exposed dominantly by (101) facets. Polyethylenimine was utilized during the combination of $TiO_2$ and graphene oxide (GO) to tune the surface charge, hindering the restack of graphene during solvothermal process and resulting in 1 to 5 layers of rGO wrapped on $TiO_2$ surface. After a further calcination, a portion of carbon quantum dots (CQDs) with a diameter about 2 nm were produced owing to the oxidizing and cutting of rGO on $TiO_2$. The as-prepared $TiO_2/rGO$ hybrid showed a highly photocatalytic activity, which is about 3.2 and 7.7 times enhancement for photodegradation of methyl orange with compared to pure $TiO_2$ and P25, respectively. We assume that the improvement of photocatalysis is attributed to the chemical bonding between rGO/CQDs and $TiO_2$ that accelerates photogenerated electron-hole pair separation, as well as enhances light harvest.

광촉매 공정에 따른 이부프로펜의 분해 특성 (Degradation Properties of Ibuprofen Using Photocatalytic Process)

  • 채금화;나승민;안윤경;이세반;김지형
    • 한국환경과학회지
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    • 제21권4호
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    • pp.411-419
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    • 2012
  • In this study, Ibuprofen (IBP) degradation by the photo catalytic process was investigated under various parameters, such as UV intensity, optimum dosage of $TiO_2$, alkalinity, temperature and pH of bulk solution. The pseudo-first order degradation rate constants were in the order of $10^{-1}$ to $10^{-4}min^{-1}$ depending on each condition. The Photocatalytic IBP degradation rate increased with an increase in the applied UV power. At high UV intensity a high rate of tri-iodide ($I_3{^-}$) ion formation was also observed. Moreover, in order to avoid the use of an excess catalyst, the optimum dosage of catalyst under the various UV intensities (30 and 40 W/L) was examined and ranged from approximately 0.1 $gL^{-1}$. The photo catalytic IBP degradation rate was changed depending on the alkalinity and temperature and pH in the aqueous solution. This study demonstrated the potential of photo catalytic IBP degradation under different conditions.

항생제 분해용 광촉매막: 리뷰 (Photocatalytic Membrane for Degradation of Antibiotics: A Review)

  • 라비아 카갛니;라즈쿠마 파텔
    • 멤브레인
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    • 제32권5호
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    • pp.304-313
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    • 2022
  • 활성 의약품 성분(APIs)의 존재가 수생 생태계와 인간의 건강에 위험하다는 증거가 있다. 물에 항생물질인 테트라사이클린과 같은 API가 존재하면 미생물에 항균제 내성(AMR)이 발생해 개인과 사회에 막대한 비용이 발생한다. TiO2 또는 비스무트 기반 촉매와 같은 촉매가 내장된 막은 유기 유출물을 분해하고 폐수로부터 분리한다. 촉매의 광촉매 활성은 귀금속 도핑 및 탄소성 물질의 첨가 및 다른 반도체와의 헤테로 접합 형성으로 향상될 수 있다. 광촉매의 회수는 고분자 막에서 광촉매의 고정화를 통해 가능하다. 이 검토에서는 물 속 항생제의 분해가 논의된다.

암모니아수를 이용한 N-doped TiO2 제조 및 부식산의 광촉매 분해 (Synthesis of N-doped Titania using Ammonium Hydroxide and Photocatalytic Degradation of Humic Acid)

  • 조아영;남윤선;이동석
    • 산업기술연구
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    • 제32권A호
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    • pp.95-102
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    • 2012
  • To advance luminance efficiency of Titania at visible range, N-doped $TiO_2$ was prepared by using ammonium hydroxide as a source of nitrogen. The photoactivities of the synthesized $TiO_2$ were evaluated on the basis of degradation of humic acid in aqueous solutions with different light sources, UV-C, UV-A and fluorescent lamp. As a result, at UV-C is high efficiency $UV_{254}$ decrease and TOC removal. In this study, the best synthetic conditions of N-doped $TiO_2$ were 5.0 M of ammonium hydroxide concentration and calcination temperature of $550^{\circ}C$. The degradation rate of humic acid as an evaluation of photoactivities of the catalysts were conducted with pH variation, decrease rate of molecular absorption, removal rate of total organic carbon and fluorescece evolution for humic acid solution. XRD and SEM were applied for analysis of surface analysis of the catalysts.

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광전기촉매 공정과 전기/UV 공정을 이용한 Rhodamine B의 색 제거 (Decolorization of a Rhodamine B Using Photoelectrocatalytic and Electrolytic/UV Process)

  • 김동석;박영식
    • 한국환경과학회지
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    • 제17권9호
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    • pp.1023-1032
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    • 2008
  • The feasibility study of the application of the photoelectrocatalytic and electrolytic/UV decolorization of Rhodamine B (RhB) was investigated in the photoelectrocatalytic and electrolytic/UV process with $TiO_2$ photoelectrode and DSA (dimensionally stable anode) electrode. Three types of $TiO_2$ photoelectrode were used. Thermal oxidation electrode (Th-$TiO_2$) was made by oxidation of titanium metal sheet; sol-gel electrode (5G-$TiO_2$) and powder electrode (P-$TiO_2$) were made by coating and then heating a layer of titania sol-gel and slurry $TiO_2$ on titanium sheet. DSA electrodes were Ti and Ru/Ti electrode. The relative performance for RhB decolorization of each of the photoelecoodes and DSA electrodes is: Ru/Ti > Ti > SG-$TiO_2$ > Th-$TiO_2$. It was observed that photoelectrocatalytic decolorization of RhB is similar to the sum of the photocatalytic and electrolytic decolorization. Therefore the synergetic effect was not showed in pthotoelectrocatalytic reaction. $Na_{2}SO_{4}$ and NaCl showed different decolorization effect between pthotoelectrocatalytic and electrolytic/UV reaction. In the presence of the NaCl, RhB decolorization of Ru/Ti DSA electrode was higher than that of the other photoelectrode and Ti electrode. Optimum current, NaCl dosage and UV lamp power of the electrolytic/UV process (using Ru/Ti electrode) were 0.75 A, 0.5 g/L and 16 W, respectively.