Pristine and cerium-doped zinc oxides with a different dopant concentration between 1 and 5% were fabricated using the hydrothermal method. Prepared materials show direct bandgaps of comparable values. Cerium-doped materials show UV-Vis spectra with broad tails toward the visible light range. Pure zinc oxide displays the flower-like form, while cerium-doped materials possess rod-shaped morphologies. The materials were tested for the degradation performance of methylene blue under visible light irradiation. To elucidate the difference in their performance, further measurements and experiments were conducted. Overall, 3%-cerium doped zinc oxide shows the greatest photocatalytic performance. This is possibly attributed to its rod shape with good uniformity and to the enrichment of oxygen vacancies in its surface layers. Finally, trapping experiments reveal that positive holes and hydroxyl radicals were the predominant active species during the photocatalytic degradation process.
The bee's nest-like nanostructured CeO 2 Al 2 O 3 powders were synthesized by combustion method using polyvinyl alcohol as a fuel and their catalytic activity were tested in the m-xylene and toluene combustion. The results showed that the catalytic reaction temperature increased monotonically from 200 to 250°C and from 250 to 300°C for the 90% conversion of m-xylene and toluene, respectively, with the calcination temperature in the range of 450850°C. For both combustions, the sample calcined at 450°C with a bee's nest-like nanostructure and average pore size of 800 nm exhibited the highest catalytic activity. Among the samples calcined at 850°C, the lowest catalytic reaction temperature for the 90% conversion of m-xylene and toluene of 250 and 300°C, respectively, was found with the sample having the equimolar ratio of Ce/Al.
Polymer nanocomposites are relatively new class of materials. Incorporation of inorganic nanoparticles into a polymer matrix can significantly influence the properties of the matrix. The obtained composite might exhibit improved thermal, mechanical and optical properties. In this study, the CeO 2 -TiO 2 nanoparticles have been applied to modify properties of polyurethane matrix in order to improve the ultra-violet (UV) absorption property of polyurethane thin films. The interdependence of mechanical properties, UV absorption property and the dispersed concentration of CeO 2 -TiO 2 nanoparticles were investigated. Results showed that, the mechanical properties of polyurethane thin films coating CeO 2 -TiO 2 nanoparticles in testing conditions such as film-forming ability, bonded coating and hardness, modulus, adhesion, impact resistance almost unaffected when the containing CeO 2 -TiO 2 nanoparticles ≤ 2 %. The survey sample was qualified; the scratches do not change the composition CeO 2 -TiO 2 ≤ 1 %. Samples containing 0.2 % CeO 2 -TiO 2 nanoparticles showed the best resistance to discoloration and most influential causes less of gloss paint. The aim of the present work is to investigate the mechanical properties and UV absorption property of CeO 2 -TiO 2 nanoparticles/urethane thin films. It is expected that the CeO 2 -TiO 2 nanoparticles would enhance the UV absorption properties of resulting CeO 2 -TiO 2 nanoparticles/urethane thin films.
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