• 제목/요약/키워드: SEM(Scanning Electron Microscopy)

검색결과 2,620건 처리시간 0.029초

Preparation and Characterization of Ordered Nanostructured Cobalt Films via Lyotropic Liquid Crystal Templated Electrodeposition Method

  • Al-Bishri, Hassan M.;El-Hallag, Ibrahim S.;El-Mossalamy, Elsayed H.
    • Bulletin of the Korean Chemical Society
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    • 제31권12호
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    • pp.3730-3734
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    • 2010
  • A simple, inexpensive and less time consuming electrochemical methods were carried out to prepare ordered mesoporous cobalt films. Ordered mesoporous cobalt films were successfully synthesized by templated electrodepostion of hexagonal $H_1$-e Co ion. The electrodeposited mesopores films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), low angle X-ray diffraction (XRD) and voltammetric methods. The applicability of thin films as high - performance super capacitors electrode materials is demonstrated electrochemically using cyclic voltammetry (CV) technique.

Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions

  • Zamani, Farzad;Rezapour, Mehdi;Kianpour, Sahar
    • Bulletin of the Korean Chemical Society
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    • 제34권8호
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    • pp.2367-2374
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    • 2013
  • Lysine (Lys) immobilized on zeolite 4A was prepared by a simple adsorption method. The physical and chemical properties of Lys/zeolite 4A were investigated by X-ray diffraction (XRD), FT-IR, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis. The obtained organic-inorganic composite was effectively employed as a heterogeneous basic catalyst for synthesis of ${\alpha},{\beta}$-unsaturated carbonyl compounds. No by-product formation, high yields, short reaction times, mild reaction conditions, operational simplicity with reusability of the catalyst are the salient features of the present catalyst.

Photocatalytic Degradation of Methylene Blue by Pd/MWCNT/TiO2 under UV and Visible Light Irradiation

  • Choi, Jong Geun;Park, Chong-Yeon;Zhu, Lei;Meng, Ze-Da;Ghosh, Trisha;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제49권6호
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    • pp.511-517
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    • 2012
  • Pd/MWCNT/$TiO_2$ composites were synthesized by a sol-gel technique using multi-walled carbon nanotubes (MWCNT), palladium (II) chlorite ($PdCl_2$) and titanium tetrachloride ($TiCl_4$) as the carbon, palladium and titanium precursors. The Pd/MWCNT/$TiO_2$ composites prepared were characterized by BET surface area measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic activity of the composites was evaluated using the degradation of methylene blue (MB) under UV and visible light irradiation as a model.

Ultrasonic Synthesis of CoSe2-Graphene-TiO2 Ternary Composites for High Photocatalytic Degradation Performance

  • Ali, Asghar;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제54권3호
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    • pp.205-210
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    • 2017
  • In this study, we examined the photo-degradation efficiency of $CoSe_2$-Graphene-$TiO_2$ ($CoSe_2-G-TiO_2$) nanocomposites under visible light irradiation using rhodamine B (RhB) as standard dye. $CoSe_2-G-TiO_2$ nanocomposites were synthesized by ultrasonication and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopic analysis and UV-Vis absorbance spectra analysis. Our results show that the $CoSe_2-G-TiO_2$ nanocomposite exhibited significant photo degradation efficiency compared to pure $TiO_2$ and $CoSe_2-G$, approximately 85.2% of the rhodamine (Rh B) degraded after 2.5 h. It is concluded that the $CoSe_2-G-TiO_2$ nanocomposite is a promising candidate for use in dye pollutants.

플라즈마 식각후 처리에 의한 Al alloy막의 부식 억제 효과 (Effects of anti-corrosion of the Al alloy film by the post-etch treatment)

  • 김환준;이철인;최현식;권광호;김창일;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.413-417
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    • 1997
  • In this study, chlorine(Cl)-based gas chemistry is generally used to etching for AlCu films metallization. The corrosion phenomena of AlCu films were examined with XPS (X-ray photoelectron spectroscopy), SEM (Scanning electron microscopy), and TEM (Transmission electron microscopy). SF$\sub$6/ plasma treatment subsequent to the etch process prevents the corrosion effectively in the pressure of 300 mTorr. It is found that the chlorine atoms on the etched surface are not substituted for fluorine atoms during SF$\sub$6/ treatment, but a passivation layer on the surface by fluorine-related compounds would be formed. The passivation layer prevents the moisture penetration on the SF$\sub$6/ treated surface and suppresses the corrosion successfully.

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초음파분무열분해법으로 제조한 ZnO:Pt막의 전기적 및 구조적 특성 (Electrical and Structural Properties of ZnO:Pt Films Prepared by Ultrasonic Spray Pyrolysis)

  • 마대영;박기철
    • 센서학회지
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    • 제13권1호
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    • pp.66-71
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    • 2004
  • Pt-doped zinc oxide (ZnO:Pt) films were deposited by ultrasonic spray pyrolysis. Resistivity variation with Pt concentration was measured. The Pt distribution in ZnO:Pt films was studied through Auger Electron Spectroscopy (AES). The ZnO:Pt films were annealed in the ambient of air, water vapor and ozone, respectively. The variation in crystallographic properties and surface morphologies with respect to the annealing condition was observed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The resistivity variation of the films with the annealing condition was measured. Finally, Atomic Force Microscopy (AFM) measurements were carried out to study the effects of the annealing on the roughness of ZnO:Pt films.

Effect of the flow rate of nitrogen sputter gas on the properties of thin zirconium oxynitride films

  • 박주연;조준모;강용철
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.384-384
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    • 2010
  • Zirconium oxynitride films were obtained by r.f. reactive magnetron sputtering of a zirconium target with nitrogen flow rate ranging from 0 to 60 sccm. The phases present in the films were determined by X-ray diffraction (XRD). Measurements of the oxidation state $ZrON_x$ films were investigated by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Thickness of these samples was estimated by spectroscopic ellipsometry (SE) and scanning electron microscopy (SEM). We found that the surface morphology of $ZrON_x$ films measured by atomic force microscopy (AFM) was also depended on the nitrogen gas flow.

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Vertically Aligned WO3-CuO Core-Shell Nanorod Arrays for Ultrasensitive NH3 Detection

  • Yan, Wenjun;Hu, Ming
    • Nano
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    • 제13권10호
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    • pp.1850122.1-1850122.6
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    • 2018
  • Vertically aligned $WO_3$-CuO core-shell nanorod arrays for $NH_3$ sensing are prepared. The sensor is fabricated by preparing $WO_3$-CuO nanorod arrays directly on silicon wafer with interdigital Pt electrodes. The $WO_3$-CuO nanorod arrays are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The sensor based on the vertically aligned $WO_3$-CuO nanorod arrays exhibits ultrasensitive $NH_3$ detection, indicating p-type behavior. The optimum sensing temperature is found to be about $150^{\circ}C$. Both response and recovery time to $NH_3$ ranging from 50 ppm to 500 ppm are around 10-15 s. A possible $NH_3$ sensing mechanism of the vertically aligned hybrid nanorod arrays is proposed.

Synthesis of Mesoporous Hollow Silica Sphere Using Water Glass: Filler for Weight Reduction of Rubber

  • Mun, Hanjun;Bae, Jae Young
    • Elastomers and Composites
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    • 제55권4호
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    • pp.277-280
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    • 2020
  • In this study, mesoporous hollow silica spheres were synthesized using a polystyrene core and cetyltriammonium chloride (CTACl) as a pore template, and a low-cost water glass instead of expensive tetraethyl orthosilicate (TEOS) as a precursor. In addition, the material was synthesized by varying the concentration of polystyrene. Later, the polystyrene core and CTACl were removed by firing in a high-temperature heat-treatment process. The synthesized product was analyzed by various methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and N2-sorption analysis. It was confirmed that the hollow silica sphere had a hexagonal structure with a Brunauer-Emmett-Teller (BET) specific area of 1623 ㎡/g.

Characterization of Burned Architectural Woods by Fire Using SEM-EDXS and Computerized Tomography

  • Lee, Hyun-Mi;Hwang, Won-Joung;Lee, Dong-Heub;Son, Dong-Won
    • Journal of the Korean Wood Science and Technology
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    • 제42권5호
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    • pp.516-522
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    • 2014
  • Old architectural wood materials damaged by a fire were evaluated on the basis of wood species and scanning electron microscopy (SEM) observation of wood tissues in combination with energy dispersive X-ray spectroscopy (EDXS) analysis. Results of SEM observation showed that tracheid wall thickness of burned parts was very thin compared with undamaged and sound wood, and tylosoid in the resin canals disappeared after the exposure to fire. SEM-EDXS analysis indicated that carbon and oxygen peaks occurred in the original energy band, and the carbon peak was higher than that of the oxygen in the burned part. A computerized tomography was also undertaken to investigate the carbonization layer formed by fire and possible internal defects.