• 제목/요약/키워드: titanium n-butoxide

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Titanium n-Butoxide의 가수분해에 의한 $TiO_2$ 분말 합성과 반응 메커니즘 (Synthesis of $TiO_2$ Powders by the Hydrolysis of Titanium n-Butoxide and Reaction Mechanism)

  • 박진구;명중재;정용선;경진범;김호건
    • 대한화학회지
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    • 제43권5호
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    • pp.505-510
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    • 1999
  • n-butanol 용매 내에서 titanium n-butoxide의 가수분해 반응에 의하여 $TiO_2$ 분말을 합성하였고, 가수분해 반응 메카니즘은 UV-Vis 분광법에 의하여 조사하였다. 가수분해 반응시 물의 농도를 과량으로 하여 반응이 유사일차반응으로 진행하도록 하였다. 이러한 농도 조건에서 얻어진 분말의 상(phase)을 XRD에 의하여 확인하였으며 반응속도는 Guggenheim method를 이용하여 계산하였다. 합성 결과 얻어진 분말은 생성 초기 비결정 상태에서 열처리 과정을 거치면서 rutile 구조로 상전이 하였다. 속도상수로부터 얻어진 물분자수(n-value)와 열역학적 파라미터로부터 titanium n-butoxide의 가수분해 반응은 Interchange-Associative(Ia)메카니즘으로 진행하는 것으로 추정되었다.

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Preparation and photocatalytic activity of ACF/$TiO_2$ composites by using titanium n-butoxide and acid modified activated carbon fiber

  • Oh, Won-Chun;Kwon, Ho-Joug;Chen, Ming-Liang;Zhang, Feng-Jun;Ko, Weon-Bae
    • 한국결정성장학회지
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    • 제19권3호
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    • pp.144-151
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    • 2009
  • Photocatalytic degradation of methylene blue (MB) in aqueous solution was investigated using $TiO_2$ coated on various acid modified activated carbon fiber (ACF). The ACFs/$TiO_2$ composites were prepared from titanium n-butoxide (TNB) as titanium precursor and various acid modified ACFs. The prepared samples are heat treated at 973 K. Then the ACF/$TiO_2$ composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX). Moreover, photocatalytic degradation of MB by the ACF/$TiO_2$ composites was determined under UV irradiation. The results shows that the photocatalytic activity of ACF/$TiO_2$ composites ($AT1{\sim}AT4$) prepared with TNB and various acid modified ACF was much better than that of ACF/$TiO_2$ composite (AT) prepared with TNB and non-acid modified ACF, and the effects improved with order of sample AT3 > AT4 > AT1 > AT2.

여러 가지 탄소 전구체와 TNB를 이용하여 탄소-$TiO_2$ 복합체를 제조 및 그들의 광촉매 특성 (Preparation of Carbon-$TiO_2$ Composites by Using Different Carbon Sources with Titanium n-Butoxide and Their Photocatalytic Activity)

  • 진명량;장봉군;장간;맹칙달;오원춘
    • Elastomers and Composites
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    • 제45권1호
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    • pp.25-31
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    • 2010
  • 우리는 탄소 전구체로 활성탄 (AC), 활성탄 섬유 (ACF)와 탄소나노튜브 (MWCNT)와 티타늄 전구체로써 TNB를 사용하여 탄소-$TiO_2$ 복합체를 제조하였으며, 이들의 특성을 SEM, TEM, BET, XRD와 EDX를 이용하여 분석하였다. 그리고 이들의 광촉매 활성은 UV 램프 조사에서 일정한 농도의 MB 용액을 이용하여 측정하였다. UV 조사한 후에 MB의 농도는 UV-vis 분광광도기를 이용하여 측정하였다.

Synthesis and Characterization of Fe-containing AC/TiO2 Composites and Their Photodegradation Effect for the Piggery Waste

  • Oh, Won-Chun
    • Environmental Engineering Research
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    • 제13권2호
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    • pp.85-92
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    • 2008
  • In this present study, we have synthesized Fe-containing AC(activated carbon)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as a titanium source to Fe treated AC through an impregnation method. The result of the textural surface properties demonstrates that there is a slight decrease in the BET surface area of composite samples with an increase of the amount of Fe treated. The surface properties of scanning electron microscope (SEM) presented a characterization of a porous texture on the Fe-containing AC/$TiO_2$ composites and homogenous compositions for Fe and titanium dioxide distributed on the sample surfaces. Fe compound peaks and a titanium dioxide structure were observed in the X-ray diffraction patterns for the Fe-containing AC/$TiO_2$ composites. The results of chemical elemental composition for the Fe-containing AC/$TiO_2$ composites showed that most of the spectra for these samples gave stronger peaks for C, O, treated Fe components and Ti metal than that of any other elements. From the photo degradation results for the piggery waste, the Fe-containing AC/$TiO_2$ composites showed an excellent degradation activity for the chemical oxygen demand (COD) due to a photocatalysis of the supported $TiO_2$, radical reaction by Fe species and the adsorptivity and absorptivity of porous carbon.

Synthesis of Expanded Graphite-Titanium Oxide Composite and its Photocatalytic Performance

  • Oh, Won-Chun;Choi, Jong-Geun;Zhang, Feng-Jun;Go, Yu-Gyoung;Chen, Ming-Liang
    • 한국세라믹학회지
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    • 제47권3호
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    • pp.210-215
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    • 2010
  • In this study, an expanded graphite-titanium oxide composite is developed from expanded graphite (EG) and titanium n-butoxide (TNB). EG is synthesized by chemical intercalation of natural graphite (NG) and rapid expansion at high temperature. TNB is used as the titanium source. The performances of the prepared EG-$TiO_2$ composite are characterized by BET surface area measurements, scan electron microscope (SEM), X-ray diffraction patterns (XRD) and energy dispersive X-ray analysis (EDX). The catalytic activities of the EG-$TiO_2$ composite are investigated by analysis of the degradation of methylene blue (MB) in aqueous solution under irradiation of UV light. Compared with the pristine $TiO_2$ and activity carbon-$TiO_2$ (AC-$TiO_2$) composite, the EG-$TiO_2$ composite shows very high efficiency against MB solution, and the EG could improve the photocatalytic effect of $TiO_2$ in the MB degradation reaction under the irradiation of UV light.

Highly donor-doped $Ba_{1-x}$$La_x$Ti$O_3$ ceramics

  • Korobova N.;Wha, Soh-Dea
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2003년도 춘계종합학술대회
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    • pp.374-377
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    • 2003
  • Sol-gel processing of BaTiO$_3$ ceramics doped with La(0.01-1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum isopropoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results suggested that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of BaTiO$_3$ powders and sintering conditions used.

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Highly Donor-doped $Ba_{1-x}La_{x}TiO_{3}$ Semiconductive Ceramics

  • Soh, Dea-Wha;Korobova N.
    • Journal of information and communication convergence engineering
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    • 제1권1호
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    • pp.31-34
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    • 2003
  • Sol-gel processing of $BaTiO_{3}$ ceramics doped with La (0.01∼1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum isopropoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results suggested that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of $BaTiO_{3}$ powders and sintering conditions used.

Comparative Analysis of the Physical Properties and Photocatalytic Effects for C/TiO2 Complexes Derived from Titanium n-butoxide

  • Oh, Won-Chun;Park, Tong-So
    • Environmental Engineering Research
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    • 제12권5호
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    • pp.218-223
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    • 2007
  • The hybrid $C/TiO_2$ complexes were prepared by a method involving the penetration of titanium n-butoxide (TNB) solution with porous carbons. The photocatalysts were investigated for their surface textural properties and SEM morphology, structural crystallinity and elemental identification between porous carbon and $TiO_2$, and dye decomposition performance. For all the $C/TiO_2$ complexes prepared by TNB solution methods, the excellent photocatalytic effect for dye degradation should be attributed to the synergitic effects between photo-decomposition of the supported $TiO_2$ and adsorptivity of the porous carbons.

Synthesis and Characterization of CNT/TiO2 Composites Thermally Derived from MWCNT and Titanium(IV) n-Butoxide

  • Oh, Won-Chun;Chen, Ming-Liang
    • Bulletin of the Korean Chemical Society
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    • 제29권1호
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    • pp.159-164
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    • 2008
  • Two kinds of CNT/TiO2 composite photocatalysts were synthesized with multi-walled carbon nanotubes (MWCNTs) and titanium(IV) n-butoxide (TNB) by a MCPBA oxidation method. Since MWCNTs had charge transfer and semiconducting, the CNT/TiO2 composite shows a good photo-degradation activity. The XRD patterns reveal that only anatase phase can be identified for MCT composite, but the HMCT composite synthesized with HCl treatment was observed the mixed phase of anatase and rutile. The EDX spectra were shown the presence as major elements of Ti with strong peaks. From the SEM results, the sample MCT and HMCT synthesized by the thermal decomposition with TNB show a homogenous sample with only individual MWCNTs covered with TiO2 without any jam-like aggregates between CNTs and TiO2. From the photocatalytic results, we could be suggested that the excellent activity of the CNT/TiO2 composites for organic dye and UV irradiation time could be attributed to combination effects between TiO2 and MWCNTs with plausible photodegradation mechanism.

Photocatalytic Activity of EG-TiO2 Composite for Various Dye Solutions Under UV Light and Visible Light

  • Go, Yu-Gyoung;Kwon, Ho-Joung;Chen, Ming-Liang;Zhang, Feng-Jun;Oh, Won-Chun
    • 한국재료학회지
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    • 제19권10호
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    • pp.555-561
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    • 2009
  • Expanded graphite (EG) is synthesized by chemical intercalation of natural graphite (NG) and rapid expansion at high temperature, with titanium n-butoxide (TNB) used as titanium source by a sol-gel method to prepare EG-TiO$_2$ composite. The performances of the prepared EG-TiO$_2$ composite are characterized by BET surface area measurement, scanning electron microscopy (SEM), X-ray diffraction patterns (XRD) and energy dispersive X-ray analysis (EDX). To compare the photocatalytic activities of the EG-TiO$_2$ composite, three kinds of dye solutions, methylene blue (MB), methylene orange (MO) and rhodamine B (RhB), and two kinds of light source, UV light and visible light (VL), are used. Comparing the results, it can be clearly seen that the degradation of all of the dye solutions under irradiation by UV light is much better than that under irradiation by visible light, and the decomposition of MB solution was better than that of both of MO and RhB solution.