• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthesis and photocatalytic activity of the MoS2 and WS2 nanoparticles in degradation of organic compounds

James, Derak J. January 2009 (has links)
Nanoparticles of MoS2 and WS2 were synthesized by decomposing the appropriate metal hexacarbonyl in the presence of sulfur dissolved in decalin at 140°C. A significant fraction of the nanoparticles was ≤ 15 nm in diameter as verified by Transmission Electron Microscopy. The process was repeated in the presence of silica and then titania to produce supported metal sulfides. The unsupported nanoparticles were found to exhibit a size-dependent shift in their threshold UV-visible absorption due to quantum confinement. Photocatalytic properties of each sulfide from synthesis in decalin were explored by using each as a catalyst in the photodegradation of methylene blue by visible light. These sulfides were also used to catalyze the photodegradation of acetone. Unsupported MoS2 and WS2 nanoparticles catalyzed the photodegradation of acetone under visible light of ≥ 400 nm wavelength. This is the first study reporting the photocatalytic properties of the unsupported WS2 nanoparticles. Photodegradation of methylene blue under ≥ 435 nm irradiation was detected using unsupported WS2 but not unsupported MoS2, likely because activity was masked by the likely photobleaching of the dye. When deposited on silica or titania, the nanosized MoS2 and WS2 could be uniformly distributed in aqueous solutions to maximize the photocatalytic efficiency. Correcting the absorbance measurements for light scattering by solids proved to be beneficial for extracting kinetic information. Both silica deposited sulfides were found to significantly increase the rate of methylene blue photodegradation, and deposited WS2 increased this rate significantly more than deposited MoS2. Similarly, both titania deposited sulfides significantly increased the rate of methylene blue photodegradation, and the deposited WS2 increased this rate significantly more than the deposited MoS2 / Synthesis of the sulfide photocatalysts -- Characterization of synthesized nanoparticles -- Photocatalytic degradation tests : setup and protocols -- Photocatalytic degradation tests : results. / Department of Chemistry
2

Synthesis and oxo-transfer properties of high-valent dioxo-tungsten and -molybdenum complexes with N, O, and S donor ligands. / CUHK electronic theses & dissertations collection

January 1999 (has links)
by Yee-Lok Wong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
3

Synthesis and adsorption properties of molybdenum(IV) sulfide and tungsten(IV) sulfide nanostructures with curved atomic layers / Title on signature form: Synthesis and adsorption properties of molybdenum (IV) sulfide and tungsten (IV) sulfide with curved atomic layers

Combs, Ryan J. 25 January 2012 (has links)
Access to abstract permanently restricted to Ball State community only / Construction of experimental setup -- Synthesis of MoS₂ and WS₂ fullerene like structures -- Synthesis of MoS₂ and WS₂ nanotube like structures -- Infrared spectroscopy of acetonitrile adsorption on synthesized MoS₂ materials. / Access to thesis permanently restricted to Ball State community only / Department of Chemistry

Page generated in 0.1201 seconds