Search results for " Visible light"
showing 10 items of 10 documents
Preparation of N-doped TiO2: characterization and photocatalytic performance under UV and visibile light
2009
Nanocrystalline N-doped TiO(2) samples were prepared by using TiCl(4) or TiOSO(4) as precursors. The powders were characterized by X-ray diffraction, BET specific surface area measurements, scanning electron microscopy, diffuse reflectance spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The photocatalytic activity was tested using the photodegradation of 4-nitrophenol under UV and visible light.Some samples were more active than commercial Degussa P25. A shift of the absorption edge to a lower energy and a stronger absorption in the visible light region were observed in the samples obtained from TiCl(4). Two absorption edges were observed in the samples derived from T…
Self-cleaning materials active in the visible range based on porphyrin-sensitised titanium dioxide
2016
In the last decades, nanostructured semiconductors played a central role in the material science scene because of their numerous applications spanning from renewable energy to organic/hybrid electronics up to photocatalysis. Titanium dioxide is one of the most used semiconductors because of its low cost, chemical stability, sustainability and versatility. Indeed, it is widely employed as photo-active or charge- transporting material in electronic devices, as photocatalyst in water de-pollution treatments etc.. Remarkably, one of the most interesting application of titanium dioxide consists of the protection and conservation of cultural heritages. Actually, TiO2 photocatalytic properties are…
Electrochemical fabrication of Cu2O/TiO2 nanotubes junctions with visible light photoactivity
2013
Efficient H2 production by photocatalytic water splitting under visible light over modified TiO2-based catalysts
2018
Efficient H2 production by photocatalytic water splitting under visible light over modified TiO2-based catalysts
N-TiO2 Photocatalysts highly active under visible irradiation for NOX abatement and 2-propanol oxidation
2013
N-doped TiO2 powders were prepared by two different sol-gel methods. Samples were characterised by X-ray diffraction (XRD), BET specific surface area measurements (SSA), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Electron Paramagnetic Resonance (EPR). XPS measurements revealed a signal at 400 eV assignable to nitrogen in the form of Ti-N-O. EPR signals are attributed to molecular NO trapped with cavities/defects possibly interacting with oxygen vacancies. The photocatalytic activity under UV and visible light was determined following the abatement of NOx and the photodegradation of 2-propanol in gas-solid systems. N…
Photocatalytic ozonation under visible light for the remediation of water effluents and its integration with an electro-membrane bioreactor
2018
Abstract Photocatalysis and photocatalytic ozonation under visible light have been applied for the purification of a complex aqueous matrix such as the grey water of Masdar City (UAE), by using N-doped brookite-rutile catalysts. Preliminary runs on 4-nitrophenol (4-NP) solutions allowed to test the reaction system in the presence of a model pollutant and to afford the relevant kinetic parameters of the process. Subsequently, the remediation of grey water effluent has been evaluated in terms of the reduction of total organic carbon (TOC) and bacterial counts. The concentration of the most abundant inorganic ionic species in the effluent has been also monitored during reaction. Photocatalytic…
Visible light apparatus for preliminary tests of x-ray optics
2006
We report a useful visible light testing procedure for a first analysis of soft X-ray grazing incidence optics (0.1-2 keV). Although diffraction is a limit in the application of this method, great advantages are obtained by running the tests in air with direct access to modify the geometrical mounting of the individual mirror shells. We present the experimental apparatus and show the first results of the investigation of light weight optics based on plastic foil material and comparison with results obtained with an X-ray beam.
Au/CeO2 Photocatalyst for the Selective Oxidation of Aromatic Alcohols in Water under UV, Visible and Solar Irradiation
2021
Au nanoparticles supported on CeO2 have been prepared and investigated as photocatalysts for the photocatalytic selective oxidation of benzyl alcohol and 4-methoxybenzyl alcohol to the correspondent benzaldehydes, in aqueous suspensions and room conditions under UV, visible and natural solar light irradiation. Au nanoparticles have been supported by impregnation (1 and 3 wt.%) on two types of CeO2 (i.e., a commercial one and a home prepared oxide obtained in the presence of NaOH as precipitation agent). The Au impregnated samples showed strong visible radiation absorption at 565–570 nm associated to localized surface plasmon resonance (LSPR). The bare CeO2 samples are activated by UV light …
Visible Light Photocatalysis by a Titania-Rhodium (III) Complex
2009
Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative
2013
Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N?-bis(2-(1- piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2- propanol. The reaction was carried out under cut-off (?> 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was …