• 제목/요약/키워드: Energy dispersive X-ray (EDX)

검색결과 306건 처리시간 0.023초

Preparation and Characterization and Visible Light Photocatalytic Activity of Fe-Treated AC/TiO2 Composites for Methylene Blue

  • Meng, Za-Da;Zhang, Kan;Oh, Won-Chun
    • 한국세라믹학회지
    • /
    • 제46권6호
    • /
    • pp.621-626
    • /
    • 2009
  • Fe-AC/Ti$O_2$ photocatalysts were prepared by a sol-gel method. The photocatalytic properties of Fe-AC/Ti$O_2$ photocatalysts for the purification of water have been investigated. The samples were characterized by scanning electron microscopy (SEM), specific surface area (BET), X-ray diffraction analysis (XRD), and energy dispersive X-ray spectroscopy (EDX). The photocatalytic activities were evaluated by the photocatalytic oxidation of methylene blue (MB) solution. It was found that the prepared Fe-AC/Ti$O_2$ composites have an excellent photocatalytic under visible light irradiation. A small amount of Fe ions in the AC/Ti$O_2$ composites could obviously enhance their photocatalytic activity. The high activities of the Fe-AC/Ti$O_2$ composites could be attributed to the results of the synergetic effects of the enhancement of the Fe element, the photocatalytic activity of Ti$O_2$, and the adsorption of AC.

Case Report of Asbestosis

  • Lee, Yong-Hwan;Chang, Hee-Kyung;Kiyoshi Sakai;Naomi Hisanaga;Chung, Yong-Hyun;Han, Jeong-Hee;Yu, Il-Je
    • Toxicological Research
    • /
    • 제17권3호
    • /
    • pp.163-165
    • /
    • 2001
  • A patient,58 years of age, with suspected 0/l pneumoconiosis since 1993, complained of a dry cough and exertioning dyspnea for 6 months. He had worked in an asbestos company for more than 20 years from 1974. He was subsequently diagnosed with an interstitial lung disease during an annual special health check-up for asbestos workers. h chest X-ray showed an interstitial lung disease and high-resolution computed tomography (HRCT) showed a round opaque asbestosis with chronic hypersensitivity pneumonitis. A pulmonary function test indicated that the patient had a mild restrictive lung disease with FEV1 1.67 litters and 82% FEVl/FVC. The bronchoalveloar larvage fluid included many asbestos bodies, indicating previous exposure to asbestos. Transmission electron microscopy (TEM) using an energy dispersive X-ray analyzer (EDX) revealed many asbestos bodies consisting of mainly crocidolite fibers (6,071$\times$$10^6$fibers/g of dry lung). The patient had an unusually high asbestos content of 6,112$\times$$10^6$ asbestos fibers/9 of dry lung.

  • PDF

Photocatalytic Degradation of Methylene Blue by CNT/TiO2 Composites Prepared from MWCNT and Titanium n-butoxide with Benzene

  • Chen, Ming-Liang;Zhang, Feng-Jun;Oh, Won-Chun
    • 한국세라믹학회지
    • /
    • 제45권11호
    • /
    • pp.651-657
    • /
    • 2008
  • In this study, CNT/$TiO_2$ composites were prepared using surface modified Multiwall carbon nanotube (MWCNT) and titanium n-butoxide (TNB) with benzene. The composites were characterized by nitrogen adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), FT-IR spectra, and UV-vis absorption spectroscopy. The UV radiation induced photoactivity of the CNT/$TiO_2$ composites was tested using a fixed concentration of methylene blue (MB, $C_{16}H_{18}N_3S{\cdot}Cl{\cdot}3H_2O$) in an aqueous solution. Finally, it can be considered that the MB removal effect of the CNT/$TiO_2$ composites is not only due to the adsorption effect of MWCNT and photocatalytic degradation of $TiO_2$, but also to electron transfer between MWCNT and $TiO_2$.

Synthesis and Characterization of ZnS and ZnS/TiO2 Nanocomposites and Their Enhanced Photo-decolorization of MB and 1,5-Diphenyl Carbazide

  • Meng, Ze-Da;Ullah, Kefayat;Zhu, Lei;Ye, Shu;Oh, Won-Chun
    • 한국세라믹학회지
    • /
    • 제51권4호
    • /
    • pp.307-311
    • /
    • 2014
  • ZnS and $ZnS/TiO_2$ were prepared by chemical deposition. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). The generation of reactive oxygen species was detected by monitoring the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). Excellent catalytic degradation of methylene blue (MB) solution was observed using the $ZnS/TiO_2$ composites during irradiation with visible light. The results show that the photocatalytic performance of $TiO_2$ nanoparticles is improved by loading with ZnS.

니켈기 자융성 합금 코팅층의 미세구조 및 마모거동에 미치는 후열처리 조건의 영향 (Effect of Heat Treatment Conditions on the Microstructure and Wear Behavior of Ni-based Self-flux Alloy Coatings)

  • 김균택;오명석;김영식
    • 동력기계공학회지
    • /
    • 제11권1호
    • /
    • pp.121-126
    • /
    • 2007
  • This study aims at investigating the effect of heat treatment conditions on the dry sliding wear behavior of thermally sprayed Ni-based self-flux alloy coatings. Ni-based self-flux alloy powders were sprayed onto a carbon steel substrate and then heat-treated at 700, 800, 900 and $1000^{\circ}C$ for 30 minutes in a vacuum furnace. Dry sliding wear tests were performed using sliding speed of 0.4 m/s and applied load of 6 N. AISI 52100 ball(diameter 8 mm) was used as counterparts. Microstructure and wear behavior of both as-sprayed and heat-treated Ni-based self-flux alloy coatings were studied using a scanning electron microscope(SEM), energy dispersive X-ray spectroscopy(EDX), electron probe micro-analysis(EPMA) and X-ray diffraction(XRD). It was revealed that microstructure and wear behavior of thermally sprayed Ni-based self-flux alloy coatings were much influenced by heat treatment conditions.

  • PDF

The Photodegradation Effect of Organic Dye for Metal Oxide (Cr2O3, MgO and V2O3) Treated CNT/TiO2 Composites

  • Chen, Ming-Liang;Bae, Jang-Soon;Yoon, Hee-Seung;Lim, Chang-Sung;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권3호
    • /
    • pp.815-820
    • /
    • 2011
  • Three kinds of organometallic compounds (chromium acetylacetonate, magnesium acetate and vanadyl acetylacetonate) were used as transition metal precursor, titanium n-butoxide and multi-walled carbon nanotube as titanium and carbon precursor to prepare metal oxide-CNT/$TiO^2$ composites. The surface properties and morphology of metal oxide-CNT/$TiO^2$ composites were by Brauer-Emett-Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The photocatalytic activity of prepared metal oxide-CNT/$TiO^2$ composites was determined by the degradation effect of methylene blue in an aqueous solution under irradiation of visible light.

Fabrication and Electro-photolysis Property of Carbon Nanotubes/Titanium Composite Photocatalysts for Methylene Blue

  • Zhang, Feng-Jun;Chen, Ming-Liang;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
    • /
    • 제30권8호
    • /
    • pp.1798-1804
    • /
    • 2009
  • In this study, we have studied on improved performance of carbon nanotubes/titanium (CNT/TiO2) structure electrode for methylene blue (MB). The composite electrodes consisting of CNTs and a titanium oxide matrix with phenol resin binder was fabricated with a mixture method. The chemical and morphological structure of CNT/Ti$O_2$ composites were characterized by means of BET surface area, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis absorption technique, Raman spectroscopy and energy dispersive X-ray (EDX). The electrode showed a remarkably enhanced performance for MB oxidation under UV illumination with or without electro-chemical reaction (ECR). Such a remarkably improved performance of the CNT/Ti$O_2$ structure electrode might be due to the enhanced MB oxidation by electro- and photo-generated electrons and holes in the CNTs and Ti$O_2$ under UV illumination with or without ECR.

Low-temperature Synthesis of Graphene-CdLa2S4 Nanocomposite as Efficient Visible-light-active Photocatalysts

  • Zhu, Lei;Oh, Won-Chun
    • 한국세라믹학회지
    • /
    • 제52권3호
    • /
    • pp.173-179
    • /
    • 2015
  • We report the facile synthesis of graphene-$CdLa_2S_4$ composite through a facile solvothermal method at low temperature. The as-prepared products were characterized by X-ray diffraction (XRD) and by Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and BET analysis, revealing the uniform covering of the graphene nanosheet with $CdLa_2S_4$ nanocrystals. The as-prepared samples show a higher efficiency for the photocatalytic degradation of typical MB dye compared with P25 and $CdLa_2S_4$ bulk nanoparticles. The enhancement of visible-light-responsive photocatalytic properties by decolorization of Rh.B dye may be attributed to the following causes. Firstly, graphene nanosheet is capable of accepting, transporting and storing electrons, and thus retarding or hindering the recombination of the electrons with the holes remaining on the excited $CdLa_2S_4$ nanoparticles. Secondly, graphene nanosheet can increase the adsorption of pollutants. The final cause is that their extended light absorption range. This work not only offers a simple way to synthesize graphene-based composites via a one-step process at low temperature but also a path to obtain efficient functional materials for environmental purification and other applications.

Hydrothermal Synthesis, Characterization and Improved Activity of a Visible-Light-Driven ZnSe-Sensitized TiO2 Composite Photocatalyst

  • Zhu, Lei;Peng, Mei-Mei;Cho, Kwang Youn;Ye, Shu;Sarkar, Sourav;Ullah, Kefayat;Meng, Ze-Da;Oh, Won-Chun
    • 한국세라믹학회지
    • /
    • 제50권6호
    • /
    • pp.504-509
    • /
    • 2013
  • In this study, ZnSe-$TiO_2$ composites were synthesized by a facile hydrothermal-assisted sol-gel process and characterized by nitrogen adsorption isotherms (77 K), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectrophotometry. The photocatalytic activity was investigated by decoloration methylene blue (MB), methyl orange (MO), and rhodamine B (Rh.B) in an aqueous solution under visible light irradiation. The results revealed that the photocatalytic activity of the ZnSe-$TiO_2$ photocatalyst was much higher than that of pure$TiO_2$. The ZnSe nanoparticles, which act as a photosensitizer, not only extend the spectral response of $TiO_2$ to the visible region but also reduce charge recombinations.

Preparation of MWCNT/TiO2 Composites by Using MWCNTs and Titanium(IV) Alkoxide Precursors in Benzene and their Photocatalytic Effect and Bactericidal Activity

  • Oh, Won-Chun;Zhang, Feng-Jun;Chen, Ming-Liang
    • Bulletin of the Korean Chemical Society
    • /
    • 제30권11호
    • /
    • pp.2637-2642
    • /
    • 2009
  • In this present paper, we prepared $MWCNT/TiO_2$ composites by using pre-oxidized multi-walled carbon nanotubes (MWCNTs) with different titanium alkoxide precursors in benzene solvent. The composites were comprehensively characterized by BET surface area, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-Vis absorption spectroscopy. The photoactivity of the prepared materials, under UV irradiation, was tested using methylene blue (MB) in aqueous solution. Finally, according to the results of MB removal experiment, it can be considered that the MB degradation infect mainly caused by photocatalytic effect of $TiO_2$. Furthermore, the bactericidal test of the composites was also determined. It was indicated that $MWCNT/TiO_2$ composites with sunlight had greater effectiveness for B. cereus, S. aureus and E. coli than any other experimental conditions.