• 제목/요약/키워드: photocatalytic properties

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Characterization of CNT/TiO2 Electrode Prepared Through Impregnation with TNB and Their Photoelectrocatalytic Properties

  • Zhang, Feng-Jun;Chen, Ming-Liang;Oh, Won-Chun
    • Environmental Engineering Research
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    • 제14권1호
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    • pp.32-40
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    • 2009
  • In this study, we have prepared three kinds of carbon nanometer tube $CNT/TiO_{2}$ electrodes through impregnation with different concentration titanium n-butoxide (TNB) solution. The prepared electrodes were characterized with surface properties, structural crystallinity, elemental identification and photoelectrocatalytic activity. The $N_2$ adsorption data showed that the composites had decreased surface area compared with the pristine CNT. This indicated the blocking of micropores on the surface of CNT, which was further supported by observation via SEM. XRD results showed patterns for the composites and a typical single and clear anatase crystal structure. The main elements such as C, O and Ti were existed for all samples from the EDX data. The catalytic efficiency of the developed electrode was evaluated by the photoelectrodegradation of methylene blue (MB). The positive potential applied in photoelectrocatalytic (PEC) oxidation was studied. It was found that photoelectrocatalytic (PEC) decomposition of MB solution could be attributed to combination effects between $TiO_2$ photocatalytic and CNT electro-assisted. Through the comparison between photocatalytic (PC) oxidation and photoelectrocatalytic (PEC) oxidation, it was found that the PEC oxidation efficiency for MB is higher than that of PC oxidation.

Synthesis of Spherical Carbons Containing Titania and Their Physicochemical and Photochemical Properties

  • Oh, Won-Chun;Kim, Jong-Gyu;Kim, Hyuk;Chen, Ming-Liang;Zhang, Feng-Jun;Meng, Ze-Da;Choi, Jong-Geun;Zhang, Kan
    • Journal of the Korean Ceramic Society
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    • 제48권1호
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    • pp.6-13
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    • 2011
  • In this study, we used activated carbon (AC) and charcoal (CH) as carbon sources with $TiO_2$ powder to prepare spherical carbons containing titania (SCCT) by using phenolic resin (PR) as a bonding agent. The physicochemical characteristics of the SCCT samples were examined by BET, XRD, SEM, EDX, iodine adsorption and compressive strength. The photocatalytic activity was evaluated by measuring the removal efficiency of three kinds of organic dyes: methylene blue (MB), methyl orange (MO) and rhodamine B (Rh.B) under a UV/SCCT system. In addition, evaluation of chemical oxygen demand (COD) of piggery waste was done at regular intervals and gave a good idea about the mineralization of wastewater.

Structure and chemical properties of TiO2 surfaces on C fiber

  • Kim, Myoung-Joo;Kim, Kwang-Dae;Dey, Nilay Kumar;Seo, Hyun-Ook;Kim, Dong-Wun;Jeong, Myoung-Geun;Kim, Young-Dok
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.81-81
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    • 2010
  • Growth of TiO2 films prepared by atomic layer deposition (ALD) was studied on C fiber. Moreover, adsorption and photocatalytic decomposition of methylene blue on TiO2 thin films were studied. Preferential growth of TiO2 on steps of C surfaces could be identified by scanning electron microscopy (SEM). X-ray Photoelectron Spectroscopy (XPS) showed thickness-dependent positive core level shift of Ti, which can be interpreted in terms of enhanced final state charging for thicker films. Adsorption and photocatalytic behaviors of TiO2 thin films will be discussed in this poster.

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Ag-modified BiOX (X=Cl, Br and I) Plates for Photocatalytic Dye Removal

  • Lee, Seung-Won;Choe, Yeong-In;Lee, Ju-Heon;Park, Yo-Han;Son, Yeong-Gu
    • Proceedings of the Korean Vacuum Society Conference
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.424.2-424.2
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    • 2014
  • Ag-modified BiOX (X=Cl, Br and I) nanoplates were synthesized by an ion-exchange reaction. We examined the fundamental properties by scanning electron microscopy (SEM), electron transmission microscopy (TEM), X-ray diffraction, UV-visible absorption, Fourier-transform infrared and photoluminescence spectroscopy. The adsorption and photocatalytic performances of the catalysts were tested with dyes under UV and visible light. A chemical scavenger method was employed to test the roles of active species (${\cdot}OH$, ${\cdot}O2-$ and h+) and understand photodegradation mechanism. Photoluminescence spectroscopy was used to examine ${\cdot}OH$ radical formation using terephthalic acid during photoirradiation.

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Structure Related Photocatalytic Properties of TiO2

  • Park, Ju-Young;Lee, Chang-Hoon;Jung, Kwang-Woo;Jung, Dong-Woon
    • Bulletin of the Korean Chemical Society
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    • 제30권2호
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    • pp.402-404
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    • 2009
  • The band structures and the densities of states at the Fermi energy for rutile, anatase and brookite phases are investigated along with the structure-photocatlaytic relationship by using DFT method. Bands are less dispersive in anatase phase than in rutile phase, and they are almost flat in brookite phase. As a result, the DOS value near the Fermi energy for brookite is highest among three types of $TiO_{2}$, which means that the numbers of electrons near the Fermi energy are largest in brookite. The calculation shows that brookite phase may exhibit highest photocatalytic efficiency among three types of $TiO_{2}$.

Evaluation of Photocatalysis-Fixed Using Titanium for Advanced Wastewater Treatment (고도처리를 위한 금속티타늄 고정화광촉매기술평가)

  • Jang, Jun-Won;Min, Jee-Eun;Park, Jae-Woo
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.815-818
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    • 2008
  • 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.

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The structural, optical and photocatalytic properties of $TiO_2$ thin films fabricated by do magnetron sputtering (직류 마그네트론 스퍼터링법으로 제조된 $TiO_2$ 박막의 구조적, 광학적 특성 및 광촉매 효과)

  • Lim, J.M.;Yang, H.H.;Kim, Y.J.;Park, J.Y.;Jeong, W.J.;Park, G.C.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.420-423
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    • 2003
  • [ $TiO_2$ ] thin films were fabricated by DC magnetron sputtering system at by controlling deposition times, ratios of $Ar:O_2$ partial presser ratio and substrate conditions. And the surface, cross-section morphology, microstructure, and composition ratio of the films were analyzed by FE-SEM, TEM and XPS. Besides, the optical absorption and transmittance of the $TiO_2$ films were measured by a UV-VIS-NIR Spectrophotometer, and photocatalytic properties were studied by G C Analyzer & Data Analysis system. As the result, when $TiO_2$ thin film was made at deposition time of 120[min] and $Ar:O_2$ ratio of 60:40, the best structural and optical properties among many thin films could be accepted. The best results of properties were as follows: thickness; $360{\sim}370[nm]$, grain size; 40[m], gap between two peak binding energy, $5.8{\pm}0.05[eV]$ ($2p_{3/2}$ peak and $2p_{1/2}$ peak of Ti was show at $458.3{\pm}0.05[eV]$ and $464.1{\pm}0.05[eV]$ respectively), binding energy; $530{\pm}0.05\;[eV]$, opticalenergy band gap; 3.4[eV].

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Visible Light Induced Photocatalytic Activity of N-doped TiO2 (질소 도핑된 이산화티타늄의 가시광 광촉매 활성 연구)

  • Lee, Seo Hee;Lee, Chang-Yong
    • Applied Chemistry for Engineering
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    • 제29권3호
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    • pp.298-302
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    • 2018
  • Photocatalytic properties of nitrogen doped titanium dioxide were investigated. Photocatalytic degradation of methylene blue under UV and visible light was carried out to characterize N-doped $TiO_2$. The result of XPS indicated that nitrogen atoms substitute for oxygen sites within the crystal structure of $TiO_2$. In the UV-Vis DRS spectra, N-doped amorphous $TiO_2$ absorbed UV light with little absorption of visible light, while the absorption of visible light of amorphous/anatase $TiO_2$ remarkably increased. Methylene blue photocatalytic degradation appeared by the irradiation of UV or visible light onto the N-doped anatase phase of $TiO_2$. However, the degradation rate of visible light was lower than that of UV light. The photocatalytic degradation rate of the amorphous/anatase $TiO_2$ sample was higher than that of the anatase $TiO_2$. These results indicate that the high surface area of amorphous/anatase $TiO_2$ sample, which was about three times larger than those of the anatase $TiO_2$ sample, may be related to small particles of N-doped anatase $TiO_2$.