1,721,034 research outputs found
Some remarks on so-called heterogeneous photocatalysis and on the mechanical application of the Langmuir-Hinshelwood kinetic model
No full textIs the Band Gap of Pristine TiO2 Narrowed by Anion- and Cation-Doping of Titanium Dioxide in Second-Generation Photocatalysts?
No full textPhotoinduced Coloration and Photobleaching of Titanium Dioxide in TiO2/Polymer Compositions upon UV- and Visible-Light Excitation of Color Centers' Absorption Bands: Direct Experimental Evidence Negating Band-Gap Narrowing in Anion-/Cation-Doped TiO2s
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Modelling heterogeneous photocatalysis by meta-oxide nanostructured semiconductor and isulator materials: factors that affect the activity and selectivity of photocatalysts
No full textEnvironmental remediation by an integrated microwave/UV illumination technique VI. A simple modified domestic microwave oven integrating an electgrodeless UV-Vis lamp to photodegrade environmental pollutants in aqueous media
No full textInteractions between different solar UVB/UVA filters container in commercial suncream and consequent loss of UV protection
No full textInorganic and organic UV filters. Their role and efficacy in suncreens and suncare products
No full textMinerals such as titanium dioxide, TiO2, and zinc oxide, ZnO, are well known active semiconductor photocatalysts used extensively in heterogeneous photocatalysis to destroy environmental pollutants that are organic in nature. They are also extensively used in sunscreen lotions as active broadband sunscreens that screen both UVB (290–320 nm) and UVA (320–400 nm) sunlight radiation and as high SPF makers. When so photoactivated by UV light, however, these two particular metal oxides are known to generate highly oxidizing radicals (OH and O2) and other reactive oxygen species (ROS) such as H2O2 and singlet oxygen, 1O2, which are known to be cytotoxic and/or genotoxic. Hydroxyl (OH) radicals photogenerated from photoactive TiO2 specimens extracted from commercial sunscreen lotions induce damage to DNA plasmids in vitro and to whole human skin cells in cultures. Accordingly, the titanium dioxide particle surface was modified to produce TiO2 specimens of considerably reduced photoactivity. Deactivation of TiO2 diminishes considerably, in some cases completely suppresses damage caused to DNA plasmids, to human cells, and to yeast cells compared to non-modified specimens exposed to UVB/UVA simulated solar radiation. The photostabilities of sunscreen organic active agents in neat polar and apolar solvents and in actual commercial formulations have been examined. With rare exceptions, the active ingredients undergo photochemical changes (in some cases form free radicals)
and the sunscreen lotions lose considerable Sun protection efficacy only after a relatively short time when exposed to simulated
sunlight UVB/UVA radiation, confirming the recent findings by Sayre et al. [R.M. Sayre, J.C. Dowdy, A.J. Gerwig, W.J. Shields,
R.V. Lloyd, Photochem. Photobiol. 81 (2005) 452]
The microwave-/photo-assisted degradation of bisphenol-A in aqueous TiO2 dispersions revisited. Re-assessment of the microwave non-thermal effect.
No full textInfluence of alcoholic and carbonyl functions in microwave-assisted and photo-assisted oxidative mineralization.
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