• Title/Summary/Keyword: titanium dioxides

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Preparation of $TiO_2$ Powder by Sol-Gel Method and Their Photocatalytic Decomposition Effect of Synthetic Detergents for Kitchen Use (졸-겔법에 의한 $TiO_2$ 분체 합성 및 주방용 합성세제의 광분해 효과)

  • Chung, Young-Joon;Roo, Wan-Ho;Yang, Chun-Hoe
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.2
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    • pp.140-147
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    • 2004
  • An aqueous solution of a commercial liquid synthetic detergent for kitchen use was photodecomposed in the presence of titanium dioxides powder under an atmosphere of air at room temperature. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R ratio($H_2O$/titanium iso-propoxide) and calcined at $500^{\circ}C$. All titanium dioxides were characterized by XRD, BET surface area analyzer and UV-VIS spectrometer. The surface area of titanium dioxides prepared at R ratio=6 appeared higher volume about 20% than commercial $TiO_2$ catalysts. XRD patterns of titania particles were observed mixing phase together with rutile and anatase type. Titanium dioxides prepared by sol-gel method show higher activity about 6% than commercial $TiO_2$ catalysts on the photocatalytic degradation of a commercial liquid synthetic detergent for kitchen. The concentration of the detergent decreased to about 90% of its initial value at illumination times of 2 hour. Illumination for 30 minutes decreased the concentration of oxygen to about one-fifth of the initial value.

A Photocatalytic Degradation of Synthetic Detergent over $TiO_2$ Catalysts Prepared by Sol-Gel Method (졸-겔법으로 제조된 $TiO_2$촉매에 의한 합성세제의 광분해)

  • 양천회;홍필선
    • Journal of the Korean Society of Safety
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    • v.16 no.3
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    • pp.76-82
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    • 2001
  • An aqueous solution of a commercial liquid synthetic detergent for kitchen use was photodecomposed in the presence of titanium dioxides ponder under an atmosphere of air at room temperature. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R R ratio($H_2O$/titanium iso-propoxide) and calcined at $500^{\circ}C$. All titanium dioxides m characterized by XRD, BET surface area analyzer and UV-VIS spectrometer. The surface mea of titanium dioxides prepared at R ratio=6 appeared higher volume about 20% than commercial $TiO_2$ catalyses. XRD patterns of titania particles were observed mixing phase together with rutile and anatase type. Titanium dioxides prepared by sol-gel method show higher activity about 6% than commercial $TiO_2$ catalysts on the Photocatalytic foundation of a commercial liquid synthetic detergent for kitchen. The concentration of the detergent decreased to about 90%, of its initial value at illumination times of 2 hour. illumination for 30 minutes decreased the concentration of oxygen to about one-fifth of the initial value.

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Synergy Effect of Sun Protection Factor Using Method of Forming Self-Assembly of Hybrid Titanium Dioxide (하이브리드 이산화티탄의 자기조직체 형성공법을 이용하여 제조된 하이브리드 이산화티탄의 자외선차단 상승효과)

  • Cho, Hyun Dae;Park, Soo Nam
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.4
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    • pp.748-758
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    • 2014
  • The purpose of this study is to find the optimum conditions for manufacturing titanium dioxide using a hybrid self-assembly forming method, to confirm the shape, properties and synergy effect of UV protection for hybrid titanium dioxide. Hybrid titanium dioxide, manufactured by forming self-assembly of different sizes consisting of two kinds of titanium dioxides, has micro titanium dioxide (250nm~300nm) for support material, Nano titanium dioxide (20~30nm) for surface material, coating support material. Adjustment experiments of $AlCl_3$ concentration and both titanium dioxide ratio were conducted to find the optimized conditions for the surface coating of titanium dioxide striking a negative charge, a sample made of the optimized process was confirmed through an optical analysis, particle size analysis, and potentiometric analysis. The SPF in-vitro value of the cosmetics samples containing hybrid titanium dioxide showed 15~30% higher levels than the cosmetics samples containing both titanium dioxides mixture.

하이브리드 이산화티탄의 자기조직체 형성공법을 이용하여 제조된 하이브리드 이산화티탄의 자외선차단 상승효과

  • Jo, Hyeon-Dae
    • Ceramist
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    • v.19 no.3
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    • pp.26-35
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    • 2016
  • The purpose of this study is to find the optimum conditions for manufacturing titanium dioxide using a hybrid self-assembly forming method, to confirm the shape, properties and synergy effect of UV protection for hybrid titanium dioxide. Hybrid titanium dioxide, manufactured by forming self-assembly of different sizes consisting of two kinds of titanium dioxides, has micro titanium dioxide (250nm~300nm) for support material, Nano titanium dioxide (20~30nm) for surface material, coating support material. Adjustment experiments of $AlCl_3$ concentration and both titanium dioxide ratio were conducted to find the optimized conditions for the surface coating of titanium dioxide striking a negative charge, a sample made of the optimized process was confirmed through an optical analysis, particle size analysis, and potentiometric analysis. The SPF in-vitro value of the cosmetics samples containing hybrid titanium dioxide showed 15~30% higher levels than the cosmetics samples containing both titanium dioxides mixture.

Adsorption Kinetic Study of Ruthenium Complex Dyes onto TiO2 Anodes for Dye-sensitized Solar Cells (DSSCs) (염료감응 태양전지용 루테늄 금속착체 염료의 이산화티타늄 전극에 대한 동적 흡착 연구)

  • An, Byeong-Kwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.11
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    • pp.929-934
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    • 2011
  • The adsorption kinetic study of ruthenium complex, N3, onto nanoporous titanium dioxide ($TiO_2$) photoanodes has been carried out by measuring dye uptake in-situ. Three simplified kinetic models including a pseudo first-order equation, pseudo second-order equation and intraparticle diffusion equation were chosen to follow the adsorption process. Kinetic parameters, rate constant, equilibrium adsorption capacities and related coefficient coefficients for each kinetic model were calculated and discussed. It was shown that the adsorption kinetics of N3 dye molecules onto porous $TiO_2$ obeys pseudo second-order kinetics with chemisorption being the rate determining step. Additionally the heterogeneous surface and the pore size distribution of porous $TiO_2$ adsorbents were also discussed.

Improving the Photo-stability of p-aramid Fiber by TiO2 Nanosol (TiO2 sol-gel 합성에 의한 파라 아라미드 섬유의 내광성 증진 연구)

  • Park, Sung-Min;Kwon, Il-Jun;Sim, Ji-Hyun;Lee, Jae-Ho;Kim, Sam-Soo;Lee, Mun-Cheul;Choi, Jong-Seok
    • Textile Coloration and Finishing
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    • v.25 no.2
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    • pp.126-133
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    • 2013
  • Although para-aramid fibers poss higher mechanical properties, they show very low resistance to sunlight exposure. This paper studied on the effect of nano-sol coated $TiO_2$ to improve the photo-stability of p-aramid fibers. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R ratio ($H_2O$/titanium iso-propoxide). All samples were characterized by XRD, TEM and UV-vis spectrometer. The mechanical properties of p-aramid fabrics by $TiO_2$ nano-sol coating before and after sunlight irradiation were measured with tensile tester. XRD pattern of titanium dioxide particles was observed by mixing phase together with rutile and anatase type. The results showed, after sunlight irradiation, the decreased mechanical properties of the fiber. Furthermore, the sunlight irradiation obviously deteriorated the surface and defected areas of the fiber severely by photo-induced chain scission and end group oxidation in air.

Dye-sensitized Solar Cells Based on Fluoran Leuco Sensitizers (플루오란 로이코 염료를 이용한 염료감응형 태양전지)

  • Jung, Hye-In;An, Byeong-Kwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.3
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    • pp.240-245
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    • 2013
  • The utilization of a fluoran leuco sensitizer, 2-anilino-6-dibutyl amino-3-methylfluoran (ODB-2), for dye-sensitized solar cells (DSSCs) was investigated through the examination of the adsorption of ODB-2 molecules onto the surfaces of porous titanium dioxide (titania, $TiO_2$) films and the photovoltaic properties of ODB-2-based DSSCs. Despite of the absence of the specific anchoring groups with titania, ODB-2 dye molecules were spontaneously adsorbed onto the titania surfaces because the lactone ring in ODB-2 was opened and changed into the carboxylic acid (-COOH) by releasing protons from the surfaces ($TiOH_2{^+}$) of titania, which consequently leads to the chemisorption reaction of ODB-2 molecules to the active sites of titania. DSSCs based on ODB-2 exhibited typical photovoltaic properties with an open-circuit voltage ($V_{OC}$) of 0.19 V, a short-circuit current ($J_{SC}$) of $0.30\;mA{\cdot}cm^{-2}$, a fill factor (FF) of 37%, and a conversion efficiency (PCE) of 0.02%.

Effect of deposition pressure on the morphology of TiO2 nanoparticles deposited on Al2O3 powders by pulsed laser deposition (펄스레이저 증착법에 의한 Al2O3 입자 표면 위 TiO2 나노입자의 코팅)

  • Choi, Bong Geun;Kim, So Yeon;Park, Cheol Woo;Park, Jae Hwa;Hong, Yoon Pyo;Shim, Kwang Bo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.4
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    • pp.167-172
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    • 2013
  • Titanium dioxides nanoparticles coated aluminum oxide powders were fabricated by pulsed laser deposition (PLD) with Nd : YAG laser at 266 nm. The Pulse laser energy is 100 mJ/pulse. During the irradiation of the focused laser on the $TiO_2$ target, Ar gas is supplied into the chamber. The gas pressure is varied in a range of $1{\times}10^{-2}$ to 100 Pa. Titanium dioxides nanoparticles deposited aluminum oxide powders were characterized by using energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HR-TEM), in order to understand the effect of Ar background gas on surface morphology and properties of the powders. The coated $TiO_2$ nanoparticles had nanosized spherical shape and the crystallite sizes of 10~30 nm. The morphology of coated $TiO_2$ nanoparticles is not affected by gas pressure. However, the particle size and crystallinity slightly increased with the increase of gas pressure. According to this technique, the size and crystallinity of nanoparticles can be easily controlled by controlling pressure during the laser irradiation.

Fabrication and Characterization of Dye-Sensitized Solar Cells Based on Rhodamine Dyes (로다민 기반 염료감응형 태양전지의 제조 및 특성 분석)

  • Choi, Kang-Hoon;Jung, Hye-In;An, Byeong-Kwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.11
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    • pp.731-736
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    • 2015
  • Rhodamine B (RhB) was utilized as a dye sensitizer for dye-sensitized solar cells (DSSCs) and its photovoltaic property was examined under the illumination of AM 1.5 G, $100mWcm^{-2}$. DSSCs based on RhB exhibited typical photovoltaic properties with an open-circuit voltage ($V_{OC}$) of 0.34 V, a short-circuit current ($J_{SC}$) of $1.55mA{\cdot}cm^{-2}$, a fill factor (FF) of 50%, and a conversion efficiency (PCE) of 0.26%. In order to further improve the photovoltaic properties of RhB-based DSSCs, the effect of (i) incorporating a strong electron-donating NCS unit into the RhB molecular backbone, (ii) combining a bis-negatively charged zinc complex anion ($Zn-dmit_2$, dmit=di-mercapto-dithiol-thione) with the amine cation of RhB, (iii) co-adsorbing RhB dyes with chenodeoxycholic acid (CDCA) molecules onto porous $TiO_2$ electrodes, was investigated and discussed.

Synthesis and Characterization of an Organometallic Ruthenium Complex Bearing 4-Picolinic Acid Ligands for Dye-Sensitized Solar Cells (DSSCs) (피콜리닉산 리간드를 갖는 염료감응형 태양전지용 루테늄 염료 합성과 특성분석)

  • Jung, Hye-In;An, Byeong-Kwan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.3
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    • pp.192-197
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    • 2016
  • A novel heteroleptic ruthenium(II) complex bearing a 4-picolinic acid unit as anchoring ligands (trans-dithiocyanato bis(4-picolinic acid)ruthenium(II) (trans-H1)) was synthesized and its chemical structure was identified by $^1H$-NMR, FT-IR and mass spectroscopy. The optical, thermal, electrochemical and dye adsorption properties of trans-H1 dye were investigated and compared with those of the gold standard ruthenium complex, Ru(4,4'-dicarboxy-2,2'-bipyridine)$_2cis(NCS)_2$ (N3). DSSCs based on trans-H1 dyes were examined under the illumination of AM 1.5 G, $100mWcm^{-2}$ and exhibited typical photovoltaic properties with an open-circuit voltage ($V_{OC}$) of 0.46 V, a short-circuit current ($J_{SC}$) of $4.10mA{\cdot}cm^{-2}$, a fill factor (FF) of 60.4%, and a conversion efficiency (PCE) of 1.14%.