Articles written in Bulletin of Materials Science
Volume 35 Issue 4 August 2012 pp 495-499
CuO/TiO2 nanocrystals grown on graphene (CuO/TiO2–GR) were prepared by a simple hydrothermal method using Cu(CH3COO)2.H2O and (NH4)2TiF6 as precursors and graphene oxide (GO) as templates. The asprepared composites were characterizated by TEM, XRD, FT–IR to determine composition and phase purity. The photocatalytic activity of the samples was evaluated by photo-degradation of methylene blue (MB) aqueous solution under UV and visible light illumination. This work may provide new insights into preparing other inorganic graphene-based composites.
Volume 41 Issue 6 December 2018 Article ID 0153
Four novel dyes containing alkynylcarbazole, namely, 2-((9$H$-carbazol-3-yl)ethynyl)-9-ethyl-9$H$-carbazole, 3,6-bis((9-ethyl-9$H$-carbazol-2-yl)ethynyl)-9$H$-carbazole, 3-(phenylethynyl)-9$H$-carbazole and 3,6-bis(phenylethynyl)-9$H$-carbazole, were synthesized on the basis of single and double substitutes by following the Sonogashira coupling method.The synthesized dyeswere then assessed as novel photosensitizers in visible-light photopolymerization to evaluate the effects of conjugation on the properties of aromatic compounds. A comparison between UV–vis and TD/DFT electron transition spectra shows that λmax in theoretical ultraviolet spectra matched well with the experimental spectra; every conjugated alkynylcarbazole dye exhibits a wide absorption band in the range of 300–400 mm. Moreover, conjugation enhancement by switching carbazoleacetylene moieties caused a red shift in the absorption bands. The theoretical study showed that the maxima $\gamma$ of these molecules ranged from $\sim$330 to 370 mm, corresponding to $\pi\to \pi^∗$ and $n\to \pi^∗$ electron transitions. Fluorescence spectroscopic data show that the strongest emission peaks exhibit a red shift because of the addition of conjugated acetylene groups. A combination of alkynyl dyes and iodonium under a halogen lamp atmosphere by visible-light photopolymerizationdisplayed a positive response to the cationic polymerization of bisphenol-A epoxy resin A and free-radical of tripropylene glycol diacrylate.
Volume 42 | Issue 3