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

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Novel Synthesis and Characterization of Pt-graphene/TiO2 Composite Designed for High Photonic Effect and Photocatalytic Activity under Visible Light

  • Ye, Shu;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제54권1호
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    • pp.28-32
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    • 2017
  • The degradation of methyl blue (MB) catalyzed by platinum (Pt)-graphene/$TiO_2$ in dark ambiance was studied. Pt-graphene/$TiO_2$ composites were prepared by simple hydrothermal method. Characterizations of composites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area (BET) analysis, and energy dispersive X-ray (EDX) analysis. UV-spectroscopic analysis of the dyes was performed by measuring the change in absorbance. The degradation of the organic dyes was calculated based on the decrease in concentration of the dyes with respect to regular time intervals. Rate coefficients for the catalytic process were successfully established and reusability tests were performed to test the stability of the used catalysts.

Photocatalytic Performance of CoS2-Graphene-TiO2 Ternary Composites for Reactive Black B (RBB) Degradation

  • Ali, Asghar;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제54권4호
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    • pp.308-313
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    • 2017
  • In this study we examined the photo-degradation efficiency of $CoS_2-G-TiO_2$ nanocomposites under visible light irritation using Reactive Black B (RBB) as standard dye, $CoS_2-G-TiO_2$ nanocomposites synthesized by facial microwave assist technique, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopic analysis. Our results show the efficiency of the $CoS_2-G-TiO_2$ ternary nanocomposite is better than $CoS_2-G$ and $TiO_2-G$ nanocomposite. The degradation efficiency of $CoS_2-G-TiO_2$ nanocomposite was found approximately 89% of Reactive Black B (RBB) degraded after 180 min. Our results will open new way for the development of a new ternary nanocomposite photocatalytic application.

Synthesis of SnO2 nanowires on one-dimensional carbonization cotton fabric

  • Khai, Tran Van;Shim, Kwang-Bo
    • 한국결정성장학회지
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    • 제22권1호
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    • pp.25-28
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    • 2012
  • Tin-oxide ($SnO_2$) nanowires have been synthesized on one-dimensional (1D) carbonization cotton fabric using chemical vapour deposition method. One-dimensional (1D) carbonization cotton fabric has been synthesized from cotton fabric using annealing process in nitrogen gas at $1000^{\circ}C$. The $SnO_2$ nanowires are single-crystalline rutile structures with 20 nm in diameter and 10 ${\mu}m$ in length. Scanning electron microscopy (SEM), x-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy and photoluminescence (PL) spectroscopy were utilized to characterize the as-synthesized products.

Te이 과량 포함된 $Sb_xTe_{1-x}$ 나노와이어 및 나노튜브의 합성 및 분석 (Synthesis and Characterization of Te-rich $Sb_xTe_{1-x}$ Nanowires and Nanotubes)

  • 이준석;노광수;정순원;윤성민;유병곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.423-423
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    • 2008
  • One dimensional (1D) nanostructures, including nanowires, nanorods, nanobelts, and nanotubes, have been the focus of current research on nanotechnology because of their fundamental significance in chemistry, physics, materials science and engineering, and potential applications in nanoelectronics. We have synthesized Te-rich $Sb_xTe_{1-x}$ nanowires and nanotubes via thermal evaporation method under vapor-solid mechanism. The physical morphology and chemical composition of the fabricated nanowires and nanotubes were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX).

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Thermal Evaporation법으로 제작한 ZnO 나노선의 온도와 산소유량에 따른 성장 특성 (Characteristics of ZnO Nanowire Fabricated by Thermal Evaporation Method Depending on Different Temperatures and Oxygen Pressure)

  • 오원석;장건익
    • 한국전기전자재료학회논문지
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    • 제21권8호
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    • pp.766-769
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    • 2008
  • Zinc oxide (ZnO) nanowires were prepared on Si substrates by a thermal evaporation method at different temperatures and $O_2$ pressure. Microstructural analysis of the obtained ZnO nanowires was performed by using transmission electron microscopy(TEM) and scanning electron microscopy(SEM). Phase analysis was done using X-ray diffraction(XRD). As the deposition temperature and oxygen pressure were increased, the diameter and length of ZnO nanowires had a tendency to increase. Based on TEM and XRD analyses, the nanowires are single crystalline in nature and consist of a single phase. According to the measurements, the ZnO nanowires grown at 1100$^{\circ}C$, Ar 50 sccm, $O_2$ 10 sccm have good properties.

Synthesis and Characterization of Metal (Pt, Pd and Fe)-graphene Composites

  • Chen, Ming-Liang;Park, Chong-Yeon;Choi, Jong-Geun;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제48권2호
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    • pp.147-151
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    • 2011
  • In this study, we prepared graphene by using the modified Hummers-Offeman method and then introduced the metals (Pt, Pd and Fe) for dispersion on the surface of the graphene for synthesis of metal-graphene composites. The characterization of the prepared graphene and metal-graphene composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). According to the results, it can be observed that the prepared graphene consists of thin stacked flakes of shapes having a well-defined multilayered structure at the edge. And the metal particles are dispersed uniformly on the surface of the graphene with an average particle size of 20 nm.

Ag-modified BiOX (X=Cl, Br and I) Plates for Photocatalytic Dye Removal

  • 이승원;최영인;이주헌;박요한;손영구
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.424.2-424.2
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    • 2014
  • Ag-modified BiOX (X=Cl, Br and I) nanoplates were synthesized by an ion-exchange reaction. We examined the fundamental properties by scanning electron microscopy (SEM), electron transmission microscopy (TEM), X-ray diffraction, UV-visible absorption, Fourier-transform infrared and photoluminescence spectroscopy. The adsorption and photocatalytic performances of the catalysts were tested with dyes under UV and visible light. A chemical scavenger method was employed to test the roles of active species (${\cdot}OH$, ${\cdot}O2-$ and h+) and understand photodegradation mechanism. Photoluminescence spectroscopy was used to examine ${\cdot}OH$ radical formation using terephthalic acid during photoirradiation.

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Electrochemical Properties and Structural Analysis of Carbon-Coated Silicon Anode for Lithium Secondary Batteries

  • Kim, Hyung-Sun;Chung, Kyung-Yoon;Cho, Byung-Won
    • 전기화학회지
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    • 제11권1호
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    • pp.37-41
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    • 2008
  • The effects of carbon-coated silicon anode on the electrochemical properties and structural change were investigated. The carbon-coated silicon powders have been prepared by thermal decomposition under argon/10wt% propylene mixed gas flow at $700^{\circ}C$. The surface and crystal structure of the synthesized materials were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Lithium cells with electrodes made from the uncoated and the carbon coated silicon anode were assembled and tested. The carbon-coated silicon particles merged together well after the insertion/extraction of lithium ions, and showed a relatively low irreversible capacity compared with the uncoated silicon particle.

Effect of Co-solvent Ratios and Solution Concentrations on Morphologies of Electrospun Zein Nanomaterials

  • Rabbani, Mohammad Mahbub;Kim, Young Hun;Yeum, Jeong Hyun
    • Current Research on Agriculture and Life Sciences
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    • 제31권1호
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    • pp.11-17
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    • 2013
  • To investigate the effects of co-solvents on the morphology of nano-scale zein materials, zein solutions were electrospun with different co-solvent ratios of EtOH/$H_2O$. Different zein solution concentrations were used to study the effects of the zein content on the electrospun materials. The resulting electrospun materials were all characterized using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The diameters of the electrospun nanoparticles and nanofibers were found to increase when increasing the EtOH ratio at certain zein concentrations. Furthermore, increasing the zein content changed the morphology of the electrospun materials from nanoparticles to nanofibers.

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첨가제에 함유된 미세한 구리합금입자의 마찰 및 마모 특성 (Friction and Wear Characteristics of Copper Alloy Fine Particles Contained in an Additive)

  • 안효석;이성철
    • Tribology and Lubricants
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    • 제12권2호
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    • pp.32-40
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    • 1996
  • The tribological role of copper alloy fine particles in an additive is not well known compared to solid lubricants such as $MoS_{2}$ and PTFE. In this experimental investigation, a series of friction and wear test was undertaken to gain a better understanding of an additive containing copper alloy fine particles and to identify the effectiveness of copper alloy particles in improving tribological performance of the lubricant. Friction and wear of specimens under lubricated contact condition were studied and the worn surfaces were characterized by AES (Auger Electron Spectroscopy), SEM (Scanning Electron Microscopy) and optical microscopy. It was revealed that a copper-contained layer was formed and this layer resulted in considerable reduction in both friction and wear due to its lubricity and anti-wear property. The analysis of worn surface revealed that copper of the fine alloy particles in the additive helps healing the worn surface by plating and filling wear pits.