• Title/Summary/Keyword: $Ag/TiO_2$

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Effect of Sputter Parameters on Crystal Structure and Optical Properties of $TiO_2$/Ag Films (스퍼터 조건에 따라 $TiO_2$/Ag 계 박막의 결정구조 및 광학특성)

  • Cha, Yeong-Won;Lee, Gyeong-Jun;Kim, Yeong-Hwan
    • Korean Journal of Materials Research
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    • v.6 no.1
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    • pp.49-56
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    • 1996
  • TiO2/Ag 계 적층형 투명 열절연 박막의 최적 제작조건 설정을 위한 기초 연구로써, 스퍼터조건에 따른 결정구조 및 광학특성 변화거동을 관찰하였다. 반응성 스퍼터링에 의한 TiO2박막 제작조건에 따른 결정구조 및 광학특성 변화거동을 관찰하였다. 반응성 스퍼터링에 의한 TiO2 박막 제작시 Po2/PAr$\leq$0.2에서는 $\alpha$-TiO2 의 결정구조였으나, Po2/PAr$\leq$0.2에서는 기판 온도(RT-37$0^{\circ}C$) 및 열처리 온도(100-80$0^{\circ}C$)에 관계없이 non-stoichiometric 화합물로 판명되어, 산소 분압비가 TiO2 의 조성제어에 가장 중요한 변수로 나타났다. TiO2 박막은 열처리 온도의 증가(100-80$0^{\circ}C$)에 따라 굴절률이 증가(2.19-2.37)하는 경향이었는데, 이는 박막의 밀도증가에서 기인하는 것으로 판단된다. Ag 박막은(111)면과 (200)면이 우세한 결정립으로, 기판 온도(RT-37$0^{\circ}C$) 및 열처리(100-80$0^{\circ}C$)에 따라 등축상의 결정립 성장을 관찰할 수 있었다.

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Preparation of Ag/TiO2 Particle for Aerobic Benzyl Alcohol Oxidation (Aerobic Benzyl Alcohol Oxidation 반응용 Ag/TiO2 제조)

  • Kim, Chang-Soo;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.24 no.6
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    • pp.663-667
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    • 2013
  • $Ag/TiO_2$ particle was prepared using various ionic liquids by wet impregnation. The properties of the particles were significantly affected by the composition of ionic liquids. This is mainly attributed to different abilities of an ionic liquid to coordinate with the silver particle, leading to various coagulation of silver particles. The catalytic activity of the prepared samples was examined for the aerobic benzyl alcohol oxidation. Among the particles, $Ag/TiO_2$ prepared with 1-octyl-3-methylimidazolium tetrafluoroborate showed the best catalytic performance.

Preparation and characterization of silver N-TiO2 co-doped PbMoO4 photocatalytic reduction of under visible light (가시광 응답형 질소 도핑된 TiO2 및 PbMoO4의 제조 및 특성평가)

  • Jo, Yong-Hyeon;Kim, Tae-Ho;Lee, Su-Wan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.258-259
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    • 2014
  • 이산화티타늄($TiO_2$)의 띠 간격 (Band-Gap) 에너지를, 자외선 영역에서 질소와 $Ag-PbMoO_4$를 이용하여 가시광 응답형 광촉매를 제조하기 위하여 실험하였다. 이와 함께 제조한 "$AgPbMoO_4+N-TiO_2$"가 $TiO_2$, $N-TiO_2$, $PbMoO_4$, $AgPbMoO_4$에 비해 에너지 흡수 파장대의 향상을 확인하고 XRD, XPS, FE-SEM, UV-vis-DRS diffuse reflectance spectroscopy 분석을 통해 특성평가 및 분말의 광촉매 활성을 염료의 광촉매 분해반응으로 규명하였다.

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Anti-bacterial effects of the Na2O-TiO2-P2O5 glass-ceramics added Ag+ ion (은이온을 함유한 Na2O-TiO2-P2O5 glass-ceramic의 항균 특성)

  • Park, No-Hyung;Yoo, Eun-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.21 no.5
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    • pp.210-213
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    • 2011
  • Glass-ceramics composed of $5Na_2O-36CaO-10TiO_2-xP_2O_5$ could be obtained with $P_2O_5$ content as following procedure: 1) leaching out $Ca_3(PO_4)_2$ crystals between $Ca_3(PO_4)_2$ and $NaTi_2(PO_4)_3$ selectively in 1 N HCl solution for 2 days, and 2) exchanging $Na^+$ ion to $Ag^+$ ion in Ag($NO_3$) solution for 1 day. Scanning electron microscope (SEM) and X-rat diffractometer (XRD) were measured to verify the proper synthesis of glass-ceramics. And anti-bacteria test was accomplished using Staphylococus aureus bacteria. In the results of anti-bacteria test, the bacteria were died perfectly after 3 hours.

Ag2Se-Graphene/TiO2 Nanocomposites, Sonochemical Synthesis and Enhanced Photocatalytic Properties Under Visible Light

  • Meng, Ze-Da;Zhu, Lei;Ghosh, Trisha;Park, Chong-Yeon;Ullah, Kefayat;Nikam, Vikram;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3761-3766
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    • 2012
  • $Ag_2Se$-Graphene/$TiO_2$ composite was synthesized by a facile sonochemical method. The as-prepared products were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectrophotometer. During the reaction, both of the reduction of graphene oxide and loading of $Ag_2Se$ and $TiO_2$ particles were achieved. The as-prepared $Ag_2Se$-Graphene/$TiO_2$ composites possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously. Hence, in the photodegradation of rhodamine B (Rh.B), a significant enhancement in the reaction rate was observed with $Ag_2Se$-Graphene/$TiO_2$ composites, compared to the pure $TiO_2$. The high activity can be attributed to the synergetic effects of high charge mobility, and red shift in absorption edge of $Ag_2Se$-Graphene/$TiO_2$ composites.

Characterization of Ag/TiO2 Nanoparticles Synthesis (Ag/TiO2미세입자 합성물의 특성 분석)

  • Kyungho Kang;Yonggi Jo;Sun-Geum Kim
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.2
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    • pp.202-207
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    • 2024
  • This study examines a manufacturing process for the photoelectrode material of dye-sensitized solar cell (DSSC) intending to increase efficiency through the surface plasmon resonance phenomenon of nanoparticles with a composite structure made of Ag and TiO2. This invention involves the use of Ag and TiO2 nanoparticles in the solar cell. These nanoparticles cause surface plasmon resonance, which amplifies and scatters incident solar energy, enhancing the dye's rate of light absorption. It also makes it possible to absorb energy in wavelength ranges that were previously difficult to do, which increases efficiency. Centrifugal separation and heat synthesis are used to create the composite metal structures, and certain combinations are used to decide the particle morphologies. To increase the efficiency of organic solar cells and DSSC, the Ag/TiO2 composite structure is therefore quite likely to be used.

Antibacterial Effect of Phosphate System as Ag$_2$O Addition ($Ag_2O$함량에 따른 Phosphate계의 항균 특성에 관한 연구)

  • 윤영진;이용수;권면주;강원호
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.2 no.2
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    • pp.91-94
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    • 2001
  • Glass ceramics composed of (5-X)$Li_2O$$XAg_2O$ㆍ36CaOㆍ$20TiO_2$.27$P_2O_5$(X=1 to 5) were prepared by melting process and 2 step heat treatment for nucleation at$610^{\circ}C$ and crystallization at $730^{\circ}C$, Fabricated crystal phases were $LiTi_2(PO_4)_3$(LTP),$AgTi_2(PO_4)_3$(AgTP)와 $\beta-Ca_3(PO_4)$. Antibacterial effects and characterizations of the glass ceramics as $Ag_2$O content were investigated. Staphylococcus aureus and Salmonella typhi were used in this study. Staphylococcus aureus and Salmonella typhi bacteria were removed 5 hours added after glass ceramics.

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Aggregation Behavior of Silver and TiO2 Nanoparticles in Aqueous Environment (수환경 특성에 따른 은과 이산화티탄 나노입자의 응집 특성 연구)

  • Lim, Myunghee;Bae, Sujin;Lee, Yong-Ju;Lee, Sung-Kyu;Hwang, Yu Sik
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.5
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    • pp.571-579
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    • 2013
  • The aggregation behaviors of silver nanoparticles (AgNPs) and titanium dioxide ($TiO_2$) nanoparticles were investigated. Time-resolved dynamic light scattering (DLS) was used to study the initial aggregation of AgNPs and $TiO_2$ over a range of mono (NaCl) and divalent ($CaCl_2$) electrolyte concentrations. The effects of pH, initial concentration of NPs and natural organic matters (NOM) on the aggregation of NPs were also investigated. The aggregation of both nanoparticles showed classical Derjaguin-Landau-Verwey-Overbeek (DLVO) type behavior. Divalent electrolyte was more efficient in destabilize the AgNPs and $TiO_2$ than monovalent electrolyte. The effect of pH on the aggregation of AgNPs was not significant. But the aggregation rate of $TiO_2$ was much higher with increasing pH. Higher NPs concentration leads to faster aggregation. Natural organic matter (NOM) was found to substantially hinder the aggregation of both AgNPs and $TiO_2$. This study found that the aggregation behavior of AgNPs and $TiO_2$ are closely associated with environmental factors such as ionic strength, pH, initial concentration of NPs and NOM.

Chacterization and Preparation of SiO2-TiO2-AgO thin Films by the Chemical Solution Process (용액법에 의한 SiO2-TiO2-AgO계 박막의 제조 및 특성에 관한 연구)

  • Kim, Sangmoon;Shim, Moon-Sik;Lim, Yongmu;Hwang, Kyuseog
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.217-222
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    • 1998
  • Coating films of $SiO_2-TiO_2-AgO$ have been prepared on soda-lime-silica slide glasses and single crystal silicon wafer by the sol-gel method using a spin-coating technique. Commercially available tetraethyl orthosilicate, titanium trichloride, and silver-nitrates were used as starting materials. The heat treatment temperature of this coating films was $500^{\circ}C$ properly, obtained from TG-DTA result. The films with thickness of 310 nm were prepared by 5 times coating. In the case of l0 mol% AgO, the film showed a crack-free and smooth surface, but the higher Ago content exhibited the more pin hole and the segregated cluster of AgO. The IR absorbance of the films decreased in the range of 400 nm to 700 nm with the increase of annealing temperature. And the reflectance of the coating films decreased and the color was changed light yellow to white yellow with the increase of Ago content.

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