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Visible Light Region (visible + light_region)
Selected AbstractsSolar Cells by Design: Photoelectrochemistry of TiO2 Nanorod Arrays Decorated with CdSeADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Jin Ho Bang Abstract One-dimensional (1D) nanostructures of TiO2 are grown directly on transparent, conductive glass substrate using hydrothermal/solvothermal methods. When employed as a photoanode in photoelectrochemical cells, the vertically aligned TiO2 nanorod array exhibits slower charge recombination at electrolyte interface as compared to mesoscopic TiO2 particulate film. Electrochemical deposition of CdSe onto TiO2 nanorod array is carried out to extend absorption into visible light region. The role of CdSe-sensitized, 1D rutile TiO2 architecture in the solar cell design is discussed. [source] Morphologies-Controlled Synthesis and Optical Properties of Bismuth Tungstate Nanocrystals by a Low-Temperature Molten Salt MethodJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2006Lijin Xie Well-crystallized bismuth tungstate (Bi2WO6) powders with different morphologies were successfully synthesized via a low-temperature molten salt method. The powders were characterized by X-ray diffraction, transmission electron microscopy, and UV-Vis, respectively. It was found that the variation of morphology of the obtained Bi2WO6 powder mainly depends on the different reaction temperatures and the weight ratio of LiNO3,NaNO3 salt to precursor. In addition, the UV-Visible absorption spectra showed that the synthesized powders had strong light absorption properties not only in the ultraviolet light but also in the visible light region. [source] Measurement of critical concentration for mesophase formation of chitosan derivatives in both aqueous and organic solutionsPOLYMER INTERNATIONAL, Issue 12 2006Yan-ming Dong Abstract A novel chitosan derivative, acryloyl chitosan (AcCs), and two N -maleoyl chitosans, MaCs-1 and MaCs-2, with different degrees of substitution were synthesized using completely deacetylated chitosan as raw material under different reaction conditions. AcCs is an amphiphilic chitosan derivative, but MaCs-1 and MaCs-2 are soluble in water and organic solvents respectively. The concentrated solutions of AcCs, MaCs-1 and MaCs-2 all demonstrated mesophases and were investigated using polarizing optical microscopy (POM). Circular dichroism (CD) was also employed for determining the critical concentration for mesophase formation. A broad peak in the visible light region of CD spectra had its origin in the appearance of the mesophase, and arose from the selective reflection of cholesteric helix pitches. The results of CD measurements agreed with those of POM. The critical concentration values for aqueous solutions were much lower than those for organic solutions, which was explained by the strong interactions between the chitosan derivatives and water. Copyright © 2006 Society of Chemical Industry [source] Highly Efficient Visible Light Plasmonic Photocatalyst Ag@Ag(Br,I)CHEMISTRY - A EUROPEAN JOURNAL, Issue 33 2010Peng Wang Abstract The new plasmonic photocatalyst Ag@Ag(Br,I) was synthesized by the ion-exchange process between the silver bromide and potassium iodide, then by reducing some Ag+ ions in the surface region of Ag(Br,I) particles to Ag0 species. Ag nanoparticles are formed from Ag(Br,I) by the light-induced chemical reduction reaction. The Ag@Ag(Br,I) particles have irregular shapes with their sizes varying from 83,nm to 1,,m. The as-grown plasmonic photocatalyst shows strong absorption in the visible light region because of the plasmon resonance of Ag nanoparticles. The ability of this compound to reduce CrVI under visible light was compared with those of other reference photocatalyst. The plasmonic photocatalyst is shown to be highly efficient under visible light. The stability of the photocatalyst was examined by X-ray diffraction and X-ray photoelectron spectroscopy. The XRD pattern and XPS spectra prove the stability of the plasmonic photocatalyst Ag@Ag(Br,I). [source] | ||||||||||