• Title/Summary/Keyword: Photocatalytic

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Removal of Humic Acid Using Titania Film with Oxygen Plasma and Rapid Thermal Annealing (산소플라즈마와 급속열처리에 의해 제조된 티타니아 박막의 휴믹산 제거)

  • Jang, Jun-Won;Park, Jae-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.3
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    • pp.29-35
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    • 2007
  • Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition (PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

Low Temperature Preparation and Photocatalytic Activity of TiO{2-x}Nx (TiO{2-x}Nx의 저온제조 및 광화학적 특성)

  • Jung, Dong-Woon
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.120-124
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    • 2010
  • $TiO_2$ and N-substituted $TiO_{2-x}N_x$ were synthesized by using precipitation method. $TiO_{2-x}N_x$ compound absorbed whole UV light as well as long wavelength of visible light (400 - 700 nm) because of the change of band gap from 3.2 eV to 1.77 eV. Results obtained revealed that $TiO_{2-x}N_x$ showed higher activity than pure $TiO_2$ or P-25 for visible-photocatalytic degradation of 1,4-dichlorobenzene.

A facile chemical synthesis of a novel photo catalyst: SWCNT/titania nanocomposite

  • Paul, Rima;Kumbhakar, Pathik;Mitra, Apurba K.
    • Advances in nano research
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    • v.1 no.2
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    • pp.71-82
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    • 2013
  • A simple chemical precipitation technique is reported for the synthesis of a hybrid nanostructure of single-wall carbon nanotubes (SWCNT) and titania ($TiO_2$) nanocrystals of average size 5 nm, which may be useful as a prominent photocatalytic material with improved functionality. The synthesized hybrid structure has been characterized by transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDAX), powder X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. It is clearly revealed that nearly monodispersed titania nanocrystals (anatase phase) of average size 5 nm decorate the surfaces of SWCNT bundles. The UV-vis absorption study shows a blue shift of 16 nm in the absorbance peak position of the composite material compared to the unmodified SWCNTs. The photoluminescence study shows a violet-blue emission in the range of 325-500 nm with a peak emission at 400 nm. The low temperature electrical transport property of the synthesized nanomaterial has been studied between 77-300 K. The DC conductivity shows semiconductor-like characteristics with conductivity increasing sharply with temperature in the range of 175-300 K. Such nanocomposites may find wide applications as improved photocatalyst due to transfer of photo-ejected electrons from $TiO_2$ to SWCNT, thus reducing recombination, with the SWCNT scaffold providing a firm and better positioning of the catalytic material.

An Experimental Study on the Removal of Chlorophenol by TiO2/H2O2/UV Using Continuous flow Reactor (연속흐름식 반응기를 이용한 TiO2/H2O2/UV에 의한 클로로페놀 제거(除去)에 관한 실험적(實驗的) 연구(硏究))

  • Lee, Sang-Hyup;Park, Joo-Suk;Park, Chung-Hyun;Kim, Dong Ha
    • Journal of Korean Society of Water and Wastewater
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    • v.12 no.3
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    • pp.55-64
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    • 1998
  • The degradation efficiency of chlorophenolic compounds in $TiO_2/H_2O_2$ combined system was compared with that of in $TiO_2$ sole system. As a result, the addition of hydrogen peroxide in photocatalytic oxidation reaction greatly enhanced the degradation efficiency of chlorophenolic compounds due to the availability of the hydroxyl radical formed on the $TiO_2$ surface. The hydrogen peroxide under UV illumination produces hydroxyl radicals that appear to be another source of hydroxyl radical formation. These results indicated the $TiO_2/H_2O_2$ combined system shows higher degradation efficiency than the $TiO_2$ sole system. Compared to another oxidation reaction, hydrogen peroxide assisted photocatalytic oxidation is more promising in practical aspect.

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The Photocatalytic Decompositions of 2-Chlorophenol on the Sn-impregnated Titania Nanoparticles and Nanotube (Sn 함침-티타니아 나노입자와 나노튜브에 놓인 2-Chlorophenol 광 분해 성능)

  • Kim, Hyun Soo;Lee, Gayoung;Park, Sun-Min;Kang, Misook
    • Journal of the Korean Ceramic Society
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    • v.49 no.5
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    • pp.461-468
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    • 2012
  • This study focuses on the difference of photocatalytic activity depending on crystal structure type of nanoparticles ($TiO_2$) and nanotubes (TNT). The photodecomposition of 2-chlorophenol on the synthesized $TiO_2$, Sn-impregnated $TiO_2$, TNT, and Snimpregnated TNT were evaluated. The characteristics of the synthesized photocatalyts, TNT, Sn/TNT, $TiO_2$, and Sn/$TiO_2$ were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis), and cyclic voltammeter (CV). The water-suspended 2-chlorophenol photodegradation over $TiO_2$ (anatase structure) catalyst was better than that over pure TNT. Particularly, the water-suspended 2-chlorophenol of 10 ppm was perfectly decomposed within 4 h over Sn/$TiO_2$ photocatalyst.