Search results for "TiO2"
showing 10 items of 283 documents
Riduzione Fotocatalitica di CO2 in Presenza di Catalizzatori Compositi GaP/TiO2
2014
Highly textured boron/nitrogen co-doped TiO2 with honeycomb structure showing enhanced visible-light photoelectrocatalytic activity
2020
International audience; In this work, we report a novel photocatalyst based on boron and nitrogen co-doped TiO2 rutile (1 1 0) honeycomb structures. The photocatalyst has been prepared by simultaneously oxidizing and doping a Ti-foil substrate at 750 degrees C. The unit cell volume and the crystallite size of grown TiO2 films were measured by Rietveld refinement analysis. The co-doping by boron and nitrogen was achieved simultaneously with the oxidation of the titanium, resulting in a rutile (1 1 0) textured TiO2 film. X-ray photoelectron spectroscopy analysis revealed the presence of Ti-O-N and Ti-O-B-N bonds, and the presence of crystal defects in the lattice was detected and displayed by…
Scanning tunneling microscopy and spectroscopy of Mo clusters grown on TiO2(110).
2007
Molybdenum was deposited in two steps (3 eq. ML and 1 eq. ML) on the light blue rutile TiO2 10) (1 x 1) surface at room temperature, each Mo deposition cycle being followed by an annealing up to 950-1000 K. This procedure was found to lead to formation of separated clusters having a size in very wide range (1-20 nm). Scanning tunneling microscopy showed a dependence of the cluster morphology as a function of the size. The scanning tunneling spectra of Mo clusters was studied as a function of cluster dimensions and discussed in comparison with photoelectron spectroscopy results previously obtained for homogeneous Mo films. The dI/d V curves do not display the valence band structure of deposi…
A comparative study for the removal of methylene blue dye by N and S modified TiO2 adsorbents
2015
Successful removal of methylene blue (MB) dye from aqueous solutions using nitrogen and sulfur modified TiO2(P25) nanoparticles has been demonstrated in this study. The modified adsorbents were characterized using various analytical methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The adsorption potential of S-TiO2, N-TiO2 and TiO2(P25) type adsorbents was tested for the removal of MB dye. The kinetic studies indicated that the adsorption of MB dye followed the pseudo-first order model, while desorption processes followed the second order model. The adsorption capacity of the adsorbent proved to be increasing as a f…
Selective Oxidation of Alcohols to Aldehydes by TiO2 Photocatalysis
2011
Photocatalytic oxidation of 4-methoxybenzyl alcohol to p-anisaldehyde in a fixed bed continuous reactor,
2008
Home-prepared anatase, rutile, and brookite TiO2 catalysts for selective photocatalytic oxidation of p-methoxybenzyl alcohol in water: reactivity and…
2008
Influence of the Substituent on Selective Photocatalytic Oxidation of Aromatic Compounds in Aqueous TiO2 Suspensions.
2006
Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.
Sunlight-induced functionalisation reactions of heteroaromatic bases with aldehydes in the presence of TiO2: A hypothesis on the mechanism
2007
In previous studies we reported a new photocatalytic system involving polycrystalline TiO2 for the selective functionalisation of heteroaromatic bases with ethers and amides. In order to extend the applications of this new reaction and to better understand the mechanism involved, we have examined aromatic and aliphatic aldehydes as acyl radical sources for the nucleophilic addition to protonated N-heteroarenes in acetonitrile as the solvent and TiO2/H2O2 as the photocatalytic system. Acyl radicals may undergo decarbonylation to yield the corresponding alkyl radicals. Acyl/alkyl derivative ratios depend on the nature of the aldehydes, and present a different distribution from that obtained i…