Synergistic effect of Ni–Ag–rutile TiO2 ternary nanocomposite for efficient visible-light-driven photocatalytic activity

P25 comprising of mixed anatase and rutile phases is known to be highly photocatalytically active compared to the individual phases. Using a facile wet chemical method, we demonstrate a ternary nanocomposite consisting of Ni and Ag nanoparticles, decorated on the surface of XTiO₂ (X: P25, rutile (R)) as an efficient visible-light-driven photocatalyst. Contrary to the current perspective, RTiO₂-based Ni–Ag–RTiO₂ shows the highest activity with the H₂ evolution rate of ∼86 μmol g⁻¹ W⁻¹ h⁻¹@535 nm. Together with quantitative assessment of active Ni, Ag and XTiO₂ in these ternary systems using high energy synchrotron X-ray diffraction, transmission electron microscopy coupled energy dispersive spectroscopy mapping evidences the metal to semiconductor contact via Ag. The robust photocatalytic activity is attributed to the improved visible light absorption, as noted by the observed band edge of ∼2.67 eV corroborating well with the occurrence of Ti³⁺ in Ti 2p XPS. The effective charge separation due to intimate contact between Ni and RTiO₂via Ag is further evidenced by the plasmon loss peak in Ag 3d XPS. Moreover, density functional theory calculations revealed enhanced adsorption of H₂ on Ti₈O₁₆ clusters when both Ag and Ni are simultaneously present, owing to the hybridization of the metal atoms with d orbitals of Ti and p orbitals of O leading to enhanced bonding characteristics, as substantiated by the density of states. Additionally, the variation in the electronegativity in Bader charge analysis indicates the possibility of hydrogen evolution at the Ni sites, in agreement with the experimental observations.

Robust photocatalytic activity of Ni–Ag–RTiO₂ is attributed to the improved visible light absorption and effective charge separation due to intimate contact between Ni and RTiO₂via Ag, as evidenced by Ti³⁺ in Ti 2p XPS and energy dispersive mapping.     

The Association of Time to Organ Procurement on Short- and Long-Term Outcomes in Kidney Transplantation

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Cell Envelope and Shape of Escherichia coli K12

Rod-shaped "ghosts" that are free of murein have been isolated from E. coli. The shape of these "ghosts" is maintained by a unit membrane soluble in sodium dodecyl sulfate. Ghosts consist of about 20-30% phospholipid (almost exclusively phosphatidylethanolamine) and 50-60% protein; a large fraction of the remaining material is lipopolysaccharide. Sodium dodecyl sulfate-gel electrophoresis reveals 4-5 different bands corresponding to molecular weights between 10,000 and 40,000. Treatment of ghosts with Pronase reduces this number to 3, and the rod shape still is not lost. Results of treatment of ghosts with a crude extract from Dictyostelium discoideum have supplied tentative evidence that at least one of these proteins is involved in the maintenance of rod shape. It does not appear too unlikely that these polypeptide chains are the final products of the genetic information specifying cellular shape.     

The global distribution of average volume of alcohol consumption and patterns of drinking

AIMS: To make quantitative estimates on a global basis of exposure of disease-relevant dimensions of alcohol consumption, i.e. average volume of alcohol consumption and patterns of drinking. DESIGN: Secondary data analysis. MEASUREMENTS: Level of average volume of drinking was estimated by a triangulation of data on per capita consumption and from general population surveys. Patterns of drinking were measured by an index composed of several indicators for heavy drinking occasions, an indicator of drinking with meals and an indicator of public drinking. Average volume of consumption was assessed by sex and age within each country, and patterns of drinking only by country; estimates for the global subregions were derived from the population-weighted average of the countries. For more than 90% of the world population, per capita consumption was known, and for more than 80% of the world population, survey data were available. FINDINGS: On the country level, average volume of alcohol consumption and patterns of drinking were independent. There was marked variation between WHO subregions on both dimensions. Average volume of drinking was highest in established market economies in Western Europe and the former Socialist economies in the Eastern part of Europe and in North America, and lowest in the Eastern Mediterranean region and parts of Southeast Asia including India. Patterns were most detrimental in the former Socialist economies in the Eastern part of Europe, in Middle and South America and parts of Africa. Patterns were least detrimental in Western Europe and in developed countries in the Western Pacific region (e.g., Japan). CONCLUSIONS: Although exposure to alcohol varies considerably between regions, the overall exposure by volume is quite high and patterns are relatively detrimental. The predictions for the future are not favorable, both with respect to average volume and to patterns of drinking.