• 제목/요약/키워드: XRD (X-ray diffraction)

검색결과 2,646건 처리시간 0.031초

Synthesis of Cobalt-Iron Prussian Blue Analogues Nanotubes by CTAB Soft-Template Method

  • Liu, Peng;Liang, Chuanghui;Xu, Jianfeng;Fang, Jian;Zhao, Jihua;Shen, Weiguo
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1336-1338
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    • 2010
  • Three cobalt-iron Prussian Blue Analogues (PBAs) nanotubes contained with different alkali metal cations of K, Rb or Cs, respectively, were prepared by using cetyltrimethylammonium bromide (CTAB)/ethanol-water micelles as soft templates. The products were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron micrograph (SEM), which confirmed the composition of the substances and their unique nanotube structures. Furthermore, the formation mechanism of the PBAs nanotubes was discussed and provided useful insight for further synthesis of nanotubes of other Prussian blue analogues.

Synthesis of CdSe-TiO2 Photocatalyst and Their Enhanced Photocatalytic Activities under UV and Visible Light

  • Lim, Chang-Sung;Chen, Ming-Liang;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
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    • 제32권5호
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    • pp.1657-1661
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    • 2011
  • In this study, CdSe-$TiO_2$ photocatalyst were synthesized by a facile solvothermal method and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and UV-vis diffuse reflectance spectrophotometer. The photocatalytic activity was investigated by degrading methylene blue (MB) in aqueous solution under irradiation of UV light as well as visible light. The absorbance of degraded MB solution was determined by UV-vis spectrophotometer. The results revealed that the CdSe-$TiO_2$ photocatalyst exhibited much higher photocatalytic activity than $TiO_2$ both under irradiation of UV light as well as visible light.

Green Synthesis of Silver and Gold Nanoparticles Using Lonicera Japonica Flower Extract

  • Nagajyothi, P.C.;Lee, Seong-Eon;An, Minh;Lee, Kap-Duk
    • Bulletin of the Korean Chemical Society
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    • 제33권8호
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    • pp.2609-2612
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    • 2012
  • A simple green method was developed for rapid synthesis of silver and gold nanoparticles (AgNPs and AuNPs) has been reported using Lonicera japonica flower extract as a reducing and a capping agent. AgNPs and AuNPs were carried out at $70^{\circ}C$. The successful formation of AgNPs and AuNPs have been confirmed by UV-Vis spectro photometer, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray Analysis (EDAX), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). To our knowledge, this is the first report where Lonicera japonica flower was found to be a suitable plant source for the green synthesis of AgNPs and AuNPs.

A Facile Approach to Fabrication of Hollow ZnO Nanoparticles

  • Cho, Gwang-Rae;Kim, Dong-Hyeon;Lee, Dong-Hoon
    • Composites Research
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    • 제31권3호
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    • pp.94-98
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    • 2018
  • Well-defined, monodispersed hollow ZnO nanoparticles were successfully synthesized by a facile one-pot solution method at room temperature. Hollow ZnO nanoparticles were fabricated using polystyrene nanoparticles as seed particles. The removal of core particles via solvent extraction yields hollow nanoparticles. The structures and morphologies of the obtained products were characterized with Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction pattern (XRD) and Scanning electron microscopy (SEM). The formation mechanism of the hollow structure of the ZnO nanoparticles was also investigated. The technique developed here is expected to be useful in the preparation other metal oxides and hollow architectures.

직접 메탄올 연료전지에서 담지체로서의 GW 응용 (Application of Graphite Nano-fiber as a supporting material in the DMFC)

  • 박인수;박경원;최종호;김영민;정두환;성영은
    • 한국전기화학회:학술대회논문집
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    • 한국전기화학회 2002년도 연료전지심포지움 2002논문집
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    • pp.197-200
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    • 2002
  • The electrooxidation of methanol was studied using carbon-supported PtRu(1:1) alloy nanoparticles In sulfuric acid solution for application to a direct methanol fuel cell. The GNF-supported catalyst showed excellent catalytic activities compared to those of Vulcan XC-72. The structure and electrocatalytic activity of carbon-supported electrocatalyst were investigated using X-ray diffraction (XRD), Transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperometry (CA), X-ray photoelectron spectroscopy (XPS). The CV and CA confirmed the advantage of GNF as the supporting material. This can be explained by assuming that the enhanced activities of GNF-supported catalyst for methanol electrooxidation were caused by the unique properties of GNF.

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Preparation and Characterization of Ultra Thin TaN Films Prepared by RF Magnetron Sputtering

  • ;조현철;이기선
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 추계학술발표대회
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    • pp.32.1-32.1
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    • 2011
  • Ultra thin tantalum nitride (TaNx) films with various thicknesses (10 nm to 40 nm) have been deposited by rf magnetron sputtering technique on glass substrates. The as deposited films were systematically characterized by several analytical techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, atomic force microscopy, UV-Vis-NIR double beam spectrophotometer and four point probe method. From the XRD results, the as deposited films are in amorphous nature, irrespective of the film thicknesses. The films composition was changed greatly with increasing the film thickness. SEM micrographs exhibited the densely pack microstructure, and homogeneous surface covered by small size grains at lower thickness deposited films. The surface roughness of the films was linearly increases with increasing the films thickness, consequently the transmittance decreased. The absorption edge was shifted towards higher wavelength as the film thickness increases.

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UV 레이저를 이용한 폴리이미드 표면 개질에 관한 연구 (Polyimide Surface Modification using UV Laser)

  • 오재용;이정한;박덕수;신보성
    • 한국레이저가공학회지
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    • 제13권3호
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    • pp.13-18
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    • 2010
  • In this paper, polyimide (PI) surface was modified by UV Laser with a low laser fluence and investigated changes of surface geometry and chemical characteristics by SEM (scanning electron microscope), X-ray diffraction (XRD), XPS (x-ray photoelectron spectroscopy) and the measurements of contact angle of water. PI surface was peeled off and modified with microstructure fabrications by photochemical ablation over the laser fluence of 50 mJ/cm2. As laser fluence increased, delamination of PI surface was occurred largely and strongly. In chemical characteristics, the O/C and N/C atomic ratios increased and contact angle decreased from $80^{\circ}$ to $40^{\circ}$.

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대기 분위기에서 ZnS의 산화에 의해 생성된 야구 배트 형상의 ZnO 결정과 음극선형광 특성 (Synthesis and Cathodoluminescence of ZnO Crystals with Baseball Bat Shape Through Oxidation of ZnS in Air Atmosphere)

  • 이근형
    • 한국전기전자재료학회논문지
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    • 제25권2호
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    • pp.110-113
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    • 2012
  • ZnO crystals with a baseball bat shape were synthesized without any catalysts through a simple thermal oxidation of ZnS powder in alumina crucible under air atmosphere. SEM images demonstrated that the bat structure was composed of two pieces of ZnO crystals, i.e hexagonal-shaped rod and inverted cone-shaped rod. X-ray diffraction (XRD) pattern revealed that the ZnO crystals had wurtzite hexagonal structure. Energy dispersive X-ray (EDX) spectrum showed that the ZnO was of high purity. A strong green emission peak at 510 nm was observed in cathodoluminescece spectrum.

무전해 구리도금 박막의 특성분석

  • 조양래;윤재식;;이연승;김형철;나사균
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.281-281
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    • 2013
  • 본 연구에서는 고출력 금속 인쇄회로기판(Metal PCB) 개발을 위해 절연층으로 양극산화막을 형성하고 이 절연층 위에 Screen Printing 법을 이용하여 Ag paste를 패턴 인쇄한 알루미늄 기판을 사용하였다. 이 기판 위에 무전해 방식으로 구리 박막을 성장시켜, 무전해 도금 조건이 구리 박막 성장에 미치는 영향에 대해 연구하였다. 무전해 도금 시, pH 농도와 plating 온도를 변화시켜 이 변화에 따른 무전해 구리도금 박막의 물리적/전기적 특성을 비교 분석하여 무전해 도금에 의해 형성된 구리 박막과 기판과의 상관 관계도 비교 검토하였다. XRD (X-ray Diffraction), 광학현미경, FE-SEM (Field Emission Scanning Electron Microscope)등을 이용하여 성장된 구리 박막 및 기판의 결정성, 표면 및 단면 형상 등을 측정하였고, XPS (X-ray Photoelectron Spectroscopy)를 이용하여 무전해 도금에 의한 Cu의 화학구조 및 불순물 상태를 조사하였다.

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플라즈마 아크 방전법으로 제조된 Fe 나노분말의 미세조직에 미치는 챔버압력 영향 (Effect of Chamber Pressure on the Microstructure of Fe Nano Powders Synthesized by Plasma Arc Discharge Process)

  • 박우영;윤철수;김성덕;유지훈;오영우;최철진
    • 한국분말재료학회지
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    • 제11권4호
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    • pp.328-332
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    • 2004
  • Fe nanopowders were successfully synthesized by plasma arc discharge (PAD) process using Fe rod. The influence of chamber pressure on the microstructure was investigated by means of X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared particles had nearly spherical shapes and consisted of metallic cores (a-Fe) and oxide shells (Fe$_{3}$O$_{4}$), The powder size increased with increasing chamber pressure due to the higher dissolution and ejection rate of H$_2$ and gas density in the molten metal.