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  • 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

Preparation, Characterization and Testing for Photocatalytic Activities of Bi2WO6-based Materials

Qin, Hanna 13 December 2012 (has links)
PdCl2/Bi2WO6 and Pd/Bi2WO6 composite photocatalysts were synthesized via a template free hydrothermal process and the respective photocatalytic activities were investigated by degradation of Rhodamine B. The new catalyst composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible (UV-vis) light diffuse reflectance spectra, respectively. By XRD, it was found that the loaded Pd species did not alter the crystal lattice of Bi2WO6 photocatalyst. Through the XPS spectra, it was found that the PdCl2/Bi2WO6 was successfully reduced by chemical reducing agents CH2O and N2H4, respectively, and palladium was present in the form of both metallic Pd and Pd ion spe-cies (Pd0 and Pd2+), while the Pd species in a NaBH4-reduced composite exhibited only metallic Pd species (Pd0). For the SEM images, it was observed that both classes of composites were constructed from plenty of nanoplates, which were closed packed with hierarchical structures. Furthermore, the removal efficiency of Rhodamine B was found to be influenced by parameters such as catalyst dosage, pollutant concentration and solution pH.
2

Preparation, Characterization and Testing for Photocatalytic Activities of Bi2WO6-based Materials

Qin, Hanna January 2012 (has links)
PdCl2/Bi2WO6 and Pd/Bi2WO6 composite photocatalysts were synthesized via a template free hydrothermal process and the respective photocatalytic activities were investigated by degradation of Rhodamine B. The new catalyst composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet visible (UV-vis) light diffuse reflectance spectra, respectively. By XRD, it was found that the loaded Pd species did not alter the crystal lattice of Bi2WO6 photocatalyst. Through the XPS spectra, it was found that the PdCl2/Bi2WO6 was successfully reduced by chemical reducing agents CH2O and N2H4, respectively, and palladium was present in the form of both metallic Pd and Pd ion spe-cies (Pd0 and Pd2+), while the Pd species in a NaBH4-reduced composite exhibited only metallic Pd species (Pd0). For the SEM images, it was observed that both classes of composites were constructed from plenty of nanoplates, which were closed packed with hierarchical structures. Furthermore, the removal efficiency of Rhodamine B was found to be influenced by parameters such as catalyst dosage, pollutant concentration and solution pH.

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