Search results for "Adsorbed water"

showing 2 items of 2 documents

Thermally Induced Structural Modification of Silica Nanoparticles Investigated by Raman and Infrared Absorption Spectroscopies

2010

We report an experimental investigation by Raman and infrared (IR) absorption spectroscopies on the structural modifications induced by isochronal thermal treatments on amorphous SiO2 nanoparticles (fumed silica). In particular, three different commercial types of this material, characterized by particle mean diameters of 7, 14, and 40 nm, were subjected to thermal treatments from 100 up to 1000 °C. We found that some properties of fumed silica, such as the SiOSi mean bond angle, ring size distribution, and surface adsorbed water content, are drastically different from those of common bulk silica materials and intimately related to the particles' dimension. The SiOSi mean bond angle, probed…

Core shellSintering effectAnalytical chemistryDehydroxylationSilica nanoparticleSurface shellThermal treatmentTypical valueNanoparticleSinteringFumed silicaThermal treatmentThree-membered ringeducation.field_of_studyWater contentAdsorbed waterRaman lineAtomic networkSilicaThermally inducedSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsSurfaceGeneral EnergysymbolsNetwork structureAbsorption (chemistry)IR measurementMaterials scienceAbsorption spectroscopyStrained structurePopulationInfrared imagingInfrared spectroscopyAbsorptionsymbols.namesakeAdsorptionAbsorption spectroscopyHighly strainedShells (structures)Physical and Theoretical ChemistryeducationFumed silicaNano silica Raman proprieta' strutturaliExperimental investigationParticle mean diameterBond angleStructural modificationSilica materialRaman spectroscopy
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The influence of Al doping on the photocatalytic activity of nanostructured ZnO: The role of adsorbed water

2018

Abstract Al doped ZnO nanoparticles (labeled as x% A-ZnO, x = 0.0, 0.5, 1.0, and 1.5) were synthesized by a simple sol-gel method, characterized and tested as photocatalysts for the degradation of a model compound under UV-light irradiation. Diffuse reflectance spectroscopy (DRS) and photoelectrochemical analysis have been performed to evidence their optical and electronic behavior. The structural features of the powders were highlighted by means of specific surface area (SSA) analysis, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman spectroscopy. Al doping results in enhanced photocatalytic activity of the modified powders with respect to pure ZnO. In particular, the h…

Materials scienceDiffuse reflectance infrared fourier transformBand gapAdsorbed water; Al-doped ZnO; Defects; Nanoparticles; Photocatalysis; Sol-gel; ZnO; Surfaces; Coatings and FilmsSettore AGR/13 - Chimica AgrariaGeneral Physics and Astronomy02 engineering and technology010402 general chemistry01 natural sciencesCoatings and Filmssymbols.namesakeNanoparticlePhotocatalysiAl-doped ZnOAdsorptionSpecific surface areaPhotocatalysisFourier transform infrared spectroscopySol-gelAdsorbed waterDopingSurfaces and InterfacesGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics0104 chemical sciencesSurfaces Coatings and FilmsSurfacesAdsorbed water; Al-doped ZnO; Defects; Nanoparticles; Photocatalysis; Sol-gel; ZnO; Surfaces Coatings and FilmsSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiChemical engineeringZnOPhotocatalysissymbolsNanoparticlesDefectsDefect0210 nano-technologyRaman spectroscopyApplied Surface Science
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