Well-Defined Au/ZnO Nanoparticle Composites Exhibiting Enhanced Photocatalytic Activities

Well-defined Au/ZnO nanoparticle composites were prepared by modifying ZnO with preformed Au nanoparticles protected with bifunctional glutathione ligand. In this approach, the Au nanoparticles were highly monodisperse and their loading on ZnO surface could be precisely controlled by the anchoring conditions. Steady-state and time-resolved photoluminescence of the composites revealed the ability of the Au nanoparticles to efficiently extract conduction band electrons from the photoexcited ZnO. The composites exhibited strongly enhanced photocatalytic activity without requiring thermal activation process in degrading organic substrates in both oxidative and reductive pathways. A clear correlation between the photocatalytic activity and the Au loading was found for both oxidative and reductive photocatalytic reactions. These results demonstrate that thiolate-protected AuNPs can significantly enhance the charge separation by extracting electrons from the photoexcited ZnO and consequently improve the photocatalytic activity of the composites

Pt-Covered Multiwall Carbon Nanotubes for Oxygen Reduction in Fuel Cell Applications

Recently one-dimensonal (1-D) Pt nanostructures have shown greatly enhanced intrinsic oxygen reduction reaction (ORR) activity (ORR kinetic current normalized to Pt surface area) and/or improved durability relative to conventional supported Pt catalysts. In this study, we report a simple synthetic route to create Pt-covered multiwall carbon nanotubes (Pt NPs/MWNTs) as promising 1-D Pt nanostructured catalysts for ORR in proton exchange membrane fuel cells (PEMFCs). The average ORR intrinsic activity of Pt NPs/MWNTs is ∼0.95 mA/cm² Pt at 0.9 V_{<i>iR</i>-corrected} versus reversible hydrogen electrode (RHE), ∼3-fold higher than a commercial catalyst −46 wt % Pt/C (Tanaka Kikinzoku Kogyo) in 0.1 M HClO₄ at room temperature. More significantly, the mass activity of Pt NPs/MWNTs measured (∼0.48 A/mg_Pt at 0.9 V_{<i>iR</i>-corrected} vs RHE) is higher than other 1-D nanostructured catalysts and TKK catalysts. The enhanced intrinsic activity of 1-D Pt NPs/MWNTs could be attributed to the weak chemical adsorption energy of OH_ads-species on the surface Pt NPs covering MWNTs

L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges

13 juillet 19271927/07/13 (A28,N9706)

MOESM2 of Differences in the gut microbiota of dogs (Canis lupus familiaris) fed a natural diet or a commercial feed revealed by the Illumina MiSeq platform

Additional file 2. The raw data of diversity indices for all samples

Table_1_Complete Genome Sequencing and Comparative Genomic Analysis of Helicobacter Apodemus Isolated From the Wild Korean Striped Field Mouse (Apodemus agrarius) for Potential Pathogenicity.docx

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