• Title/Summary/Keyword: $V_2O_5$

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Electrical Properties of $V_2O_5$ Thin Films for the uncooled Infrared Detector (비냉각 적외선 감지소자 응용을 위한 $V_2O_5$ 박막의 전기적 특성)

  • Nam, Sung-Pill;Lee, Sung-Gap;Bea, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.116-117
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    • 2007
  • The $V_2O_5$ thin films deposited on Pt/Ti/$SiO_2$/Si substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_2O_5$ thin films annealed at $300^{\circ}C$ were 37.7, with a dielectric loss of 2.535, respectively. Also, the TCR values of the $V_2O_5$ thin films annealed at $300^{\circ}C$ were about -2.65%/K.

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Effect of Vanadium Oxide Loading on SCR Activity and $SO_2$ Resistance over $TiO_2$-Supported $V_2O_5/TiO_2$ Commercial De-NOx Catalysts (상용 $V_2O_5/TiO_2$ 촉매의 바나듐 함량이 SCR 반응성과 $SO_2$ 내구성에 미치는 영향)

  • Park, Kwang Hee;Cha, Wang Seog
    • Applied Chemistry for Engineering
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    • v.23 no.5
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    • pp.485-489
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    • 2012
  • We investigated vanadium (V) loading effects on selective catalytic reduction (SCR) activity and $SO_2$ resistance using commercial SCR catalysts applied on a power plant and incinerator with different amounts of V loading. These catalysts were characterized using XRD, Raman, ICP, BET analysis and found to contain $TiO_2$ (anatase) supported $V_2O_5$ added $WO_3$ and $SiO_2$. The SCR activity of the catalysts increased by increasing either the $V_2O_5$ or the $WO_3$ loading amounts; the SCR activity of the catalysts added $WO_3$ is higher than that of $WO_3$-free catalysts. As the V loading amount in the catalyst increased, the $SO_2$ durability decreased. The $V_2O_5$ supported $TiO_2$ catalyst added $WO_3$ and $SiO_2$ inhibits the deactivation process by $SO_2$. The $SO_2$ resistance of catalysts added $SiO_2$ is higher than that of catalysts added $WO_3$.

Catalytic Conversion of 1,2-Dichlorobenzene Using V2O5/TiO2 Catalysts by a Thermal Decomposition Process (기상고온합성 V2O5/TiO2 촉매에 의한 1,2-Dichlorobenzene 제거 특성)

  • Chin, Sung-Min;Jurng, Jong-Soo;Lee, Jae-Heon
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1273-1279
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    • 2008
  • This study examined the catalytic destruction of 1,2-dichlorobenzene on ${V_2}{O_5}/TiO_2$ nanoparticles. The ${V_2}{O_5}/TiO_2$ nanoparticles were synthesized by the thermal decomposition of vanadium oxytripropoxide and titanium. The effects of the synthesis conditions, such as the synthesis temperature and precursor heating temperature, were investigated. The specific surface areas of ${V_2}{O_5}/TiO_2$ nanoparticles increased with increasing synthesis temperature and decreasing precursor heating temperature. In addition, the removal efficiency of 1,2-dichlorobenzene was promoted by a decrease in heating temperature. However, the removal efficiency of 1,2-dichlorobenzene was decreased by an anatase to rutile phase transformation at temperatures $1,300^{\circ}C$.

Titanium Isopropoxide (TTIP) Treatment Strategy for V2O5-WO3/TiO2 SCR Catalysts with a Wide Operating Temperature (넓은 작동 온도범위를 가지는 V2O5-WO3/TiO2 SCR 촉매 개발을 위한 티타늄 이소프로폭사이드(TTIP) 활용 전략)

  • Jaeho Lee;Gwang-hun Cho;Geumyeon Lee;Changyong Yim;Young-Sei Lee;Taewook Kim
    • Applied Chemistry for Engineering
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    • v.34 no.4
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    • pp.357-364
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    • 2023
  • Selective catalytic reduction (SCR) is the most effective method for reducing nitrogen oxide emissions, but the operating temperature range of V2O5-WO3/TiO2 catalysts is narrow (300~400℃). In this study, a new catalyst with an operating temperature range of 200~450℃ was developed. The catalyst poison, ammonium bisulfate, generated during the SCR process can be removed by heating above 350℃. To increase the number of active sites and promote the dispersion of active materials, titanium isopropoxide (TTIP) treatment was performed on the TiO2 support with various TTIP/TiO2 mass ratios. Among them, the 5 wt% TTIP loaded catalyst showed improved performance due to higher thermal stability caused by high W dispersion and the formation of V5+. In addition, the 5 wt% TTIP-loaded catalyst prepared by a one-step co-precipitation method showed greater V-OH and W-OH dispersion and enhanced interactions in contrast to conventional methods, resulting in higher catalytic activity at lower temperatures. This review article aims to provide an accessible explanation for researchers investigating how to improve the surface properties of TiO2 catalysts using TTIP.

Charge/discharge Properties of $V_2O_5$-AC Composite for Supercapacitor (Supercapacitor용 $V_2O_5$-AC Composite의 충방전 특성)

  • 김명산;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.366-369
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    • 1999
  • The purpose of this study is to research and develop V2Os-AC(activated carbon) composite electrode for supercapacitor. Supaercapacitor cell of V2Os-AC composite electrode with 25P70FLiCIO$_{4}$/PC$_{10}$/EC$_{10}$ polymer electrolyte bring out good capacitor Performance below 3V. The discharge capacitance of V2Os-AC(30:70) composite with 70wt.% AC in 1st and 200th cycles was 9.6 and 8.2 F/g at current density of 1m7/cm2. The capacitance of V$_2$O$_{5}$-AC composite with 70wt.% AC capacitor was larger than that of others. The coulombic efficiency of supercapacitor at discharge process of 1 and 200 cycles were 96 and 100%, respectively. V$_2$O$_{5}$-AC composite supercapacitor with 70wt.% AC content showed good capacitance and stability with cycling.ing.ing.

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Ag and Cu Precipitation in Multi-Layer Chip Inductors Prepared with V2O5 Doped NiCuZn Ferrites (V2O5 도핑된 NiCuZn 페라이트로 제조된 칩인덕터에서의 Ag/cu 석출)

  • Je, Hae-June;Kim, Byung-Kook
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.503-508
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    • 2003
  • The purpose of this study is to investigate the effect of $V_2$$O_{5}$ addition on the Ag and Cu precipitation in the NiCuZn ferrite layers of 7.7${\times}$4.5${\times}$1.0 mm sized multi-layer chip inductors prepared by the screen printing method using 0∼0.5 wt% $V_2$$O_{5}$ -doped ferrite pastes. With increasing the $V_2$$O_{5}$ content and sintering temperature, Ag and Cu oxide coprecipitated more and more at the polished surface of ferrite layers during re-annealing at $840^{\circ}C$. It was thought that during the sintering process, V dissolved in the NiCuZn ferrite lattice and the Ag-Cu liquid phase of low melting point was formed in the ferrite layers due to the Cu segregation from the ferrite lattice and Ag diffusion from the internal electrode. During re-annealing at $840^{\circ}C$, the Ag-Cu liquid phase came out the polished surface of ferrite layers, and was decomposed into the isolated Ag particles and the Cu oxide phase during the cooling process.

Large-Scale Assembly of Aligned Graphene Nanoribbons with Sub 30-nm Width

  • Kim, Taekyeong
    • Journal of the Korean Chemical Society
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    • v.58 no.6
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    • pp.524-527
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    • 2014
  • We report a simple yet efficient method to assemble large-scale aligned graphene nanoribbons (GNRs) with a width as small as 30 nm. The $V_2O_5$ nanowires (NWs) were aligned on a graphene surface via spraying a solution of the $V_2O_5$ NWs, and the graphene was selectively etched by the reactive ion etching method using the $V_2O_5$ NWs as a shadow mask. This process allowed us to prepare large scale patterns of the aligned GNRs on a $SiO_2$ substrate. The orientation of the aligned and randomly oriented GNRs was compared by the atomic force microscope (AFM) images. We achieved the highly aligned GNRs along the flow direction of the $V_2O_5$ NWs solution. Furthermore, we successfully fabricated a field effect-transistor with the aligned GNRs and measured its electrical properties. Since our method enable to prepare the aligned GNRs over a large area, it should open up new way for the various applications.

Electrochemical Properties of LiCoO2 Prepared by Mechanochemical Process (Mechanochemical Process로 제조된 LiCoO2의 전기화학적 특성)

  • Cho, Byung-Won;Lee, Joong Kee;Lee, Jae-Ryong;Kim, Su-Jin;Lee, Kwan-Young;Na, Byung-Ki
    • Korean Chemical Engineering Research
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    • v.46 no.1
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    • pp.69-75
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    • 2008
  • Discharge capacity of $LiCoO_2$ in preparation by mechanochemical process decreased remarkably over 4.3V. However, Zr coating of $LiCoO_2$ showed very stable electrochemical properties up to 4.5V. Zr coating of $LiCoO_2$ in this experiment showed the discharge capacity of 197 mAh/g at 3.0-4.5V, and it maintained 96% of the initial discharge capacity after 50 cycle of charge/discharge.

Synthesis of P2O5-V2O5-ZnO Glass Frit for Laser Sealing of OLED by the Addition of Filler (필러 첨가에 의한 OLED의 레이저 실링용 P2O5-V2O5-ZnO 유리프릿의 제조)

  • Bang, Jae-Chul
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.9
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    • pp.571-576
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    • 2015
  • In this study, we developed a lead-free $P_2O_5-V_2O_5-ZnO$ glass frit for sealing OLED using laser irradiation. The frit satisfied the characteristics required for laser sealing such as low glass transition temperature, low coefficient of thermal expansion (CTE), high water-resistance, and high absorption at the wavelength of the laser beam. Ceramic fillers were added to the glass frit in order to further reduce and match its CTE with that of the commercial glass substrate. The addition of Zirconium Tungsten Phosphate (ZWP) to the frit yielded the most desirable results, reducing the CTE to $45.4{\times}10^{-7}/^{\circ}C$, which is very close to that of the glass substrate ($44.0{\times}10^{-7}/^{\circ}C$). Successful formation of a solid sealing layer was observed by optical and scanning electron microscopy.