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RESEARCH PRODUCT
Surfactant-Mediated Morphology and Photocatalytic Activity of α‑Ag2WO4 Material
Elson LongoNadia G. MacedoJuan AndrésAmanda F. GouveiaLourdes GraciaRoman Alvarez RocaMarcelo AssisEdson R. Leitesubject
photocatalytic activityMaterials scienceAnalytical chemistryInfrared spectroscopy02 engineering and technology010402 general chemistry01 natural sciencesdyeslaw.inventionchemistry.chemical_compoundlawmorphologyPhysical and Theoretical ChemistrySodium dodecyl sulfateSpectroscopyinfrared spectroscopyRietveld refinementenamels021001 nanoscience & nanotechnology0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsGeneral EnergychemistryTransmission electron microscopyelectron diffractionSelected area diffractionElectron microscopeWulff construction0210 nano-technologydescription
In the present work, the morphology (hexagonal rod-like vs cuboid-like) of an α-Ag2WO4 solid-state material is manipulated by a simple controlled-precipitation method, with and without the presence of the anionic surfactant sodium dodecyl sulfate (SDS), respectively, over short reaction times. Characterization techniques, such as X-ray diffraction analysis, Rietveld refinement analysis, Fourier-transform (FT) infrared spectroscopy, FT Raman spectroscopy, UV–vis spectroscopy, transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive X-ray spectroscopy, field emission-scanning electron microscopy (FE-SEM), and photoluminescence emission, are employed to disclose the structural and electronic properties of the α-Ag2WO4 material. First-principles calculations were performed to (i) obtain the relative stability of the six low-index surfaces of α-Ag2WO4; (ii) rationalize the crystal morphologies observed in FE-SEM images (using the Wulff construction); and (iii) determine the energy profiles associated with the transformation process between both morphologies induced by the presence of SDS. Finally, we demonstrate a relationship between morphology and photocatalytic activity, evaluated by photodegradation of Rhodamine B dye under UV light, based on the different numbers of unsaturated superficial Ag and W cations (local coordination, i.e., clusters) of each surface.
year | journal | country | edition | language |
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2018-03-28 |