Low Metal Loading (Au, Ag, Pt, Pd) Photo‐Catalysts Supported on TiO2 for Renewable Processes

Photo‐catalysts based on titanium dioxide, and modified with highly dispersed metallic nanoparticles of Au, Ag, Pd and Pt, either mono‐ or bi‐metallic, have been analyzed by multiple characterization techniques, including XRD, XPS, SEM, EDX, UV‐Vis and N2 adsorption/desorption. Mono‐metallic photo‐catalysts were prepared by wet impregnation, while bi‐metallic photocatalysts were obtained via deposition‐precipitation (DP). The relationship between the physico‐chemical properties and the catalyst’s behavior for various photo‐synthetic processes, such as carbon dioxide photo‐reduction to liquid products and glucose photo‐reforming to hydrogen have been investigated. Among the tested materials, the catalysts containing platinum alone (i.e., 0.1 mol% Pt/TiO2) or bi‐metallic gold‐containing materials (e.g., 1 wt% (AuxAgy)/TiO2 and 1 wt% (AuxPtz)/TiO2) showed the highest activity, presenting the best results in terms of productivity and conversion for both applications. The textural, structural and morphological properties of the different samples being very similar, the main parameters to improve performance were function of the metal as electron sink, together with optoelectronic properties. The high activity in both applications was related to the low band gap, that allows harvesting more energy from a polychromatic light source with respect to the bare TiO2. Overall, high selectivity and productivity were achieved with respect to most literature data

Who You Gonna Call?: Creating a Call List for Your Facility\u27s Disaster Plan

Preservation can involve responding to active and pressing matters. But not all buildings are lost to the bulldozer. Many are lost to natural and human disasters like storms and water. A Disaster Plan is a common document used by museums and history organizations. Learn how to develop a contact list for a Disaster Response Plan so you know whom to call when disaster strikes

Bacterial Colonization of Low‐Wettable Surfaces is Driven by Culture Conditions and Topography

Effect of surface low‐wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria's fate on such surfaces immersed in liquid as well as causal factors is poorly understood. This question is addressed by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability, and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24 h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecule‐poor liquids and for short‐term culture only. Complex statistical analysis demonstrates that bacterial colonization on these low‐wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating's properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization‐prevention properties in nutritive media when topography is masked by fouling. Even after long‐term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping

Nanostructuring of Fe films by oblique incidence deposition on a FeSi2 template onto Si(111): Growth, morphology, structure and faceting

International audienceThe growth of thin Fe films deposited at oblique incidence on an iron silicide template onto Si(111) single crystal has been investigated as a function of Fe thickness (0 < tFe 6 180 monolayers (MLs)) and incidence angle (0 6 h 6 80). The growth mode is determined in situ by means of scanning tunnelling microscopy (STM) and low energy electron diffraction (LEED). Stripes oriented perpendicularly to the incident atomic flux are formed for hP30. Self-correlation functions are used to extract characteristic lengths from STM images. The correlation lengths in the direction of the incident flux (nx) and perpendicular to the atomic flux (ny) grow with different powers versus time (nx / tr and ny / tq, with r = 0.34 ± 0.03 and q = 0.67 ± 0.03) following the exact solution of the (1 + 1) dimensional Kardar–Parisi–Zhang (KPZ) equation. The root mean square roughness follows also a scaling law for tFe < 120 ML leading to a growth exponent b = 0.73 ± 0.02. Shadowing and steering effects are discussed on the basis of our STM data

Nanostructuring of Fe films by oblique incidence deposition on a FeSi2 template onto Si(111): Growth, morphology, structure and faceting

International audienceThe growth of thin Fe films deposited at oblique incidence on an iron silicide template onto Si(111) single crystal has been investigated as a function of Fe thickness (0 < tFe 6 180 monolayers (MLs)) and incidence angle (0 6 h 6 80). The growth mode is determined in situ by means of scanning tunnelling microscopy (STM) and low energy electron diffraction (LEED). Stripes oriented perpendicularly to the incident atomic flux are formed for hP30. Self-correlation functions are used to extract characteristic lengths from STM images. The correlation lengths in the direction of the incident flux (nx) and perpendicular to the atomic flux (ny) grow with different powers versus time (nx / tr and ny / tq, with r = 0.34 ± 0.03 and q = 0.67 ± 0.03) following the exact solution of the (1 + 1) dimensional Kardar–Parisi–Zhang (KPZ) equation. The root mean square roughness follows also a scaling law for tFe < 120 ML leading to a growth exponent b = 0.73 ± 0.02. Shadowing and steering effects are discussed on the basis of our STM data

Vers des éco-composites à base de fibres de lin plus performants et respectueux de l’environnement grâce à la fluoration directe sous F2

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Origin of the magnetic anisotropy in ferromagnetic layers deposited at oblique incidence

Ferromagnetic films evaporated at oblique incidence show invariably an uniaxial in-plane magnetic anisotropy component with easy axis perpendicular to the incidence plane. Scanning Tunneling Microscopy (STM) images reveal that oblique deposition results in rough films with highly anisotropic correlation functions of the surface profile. We show that simple shape anisotropy calculations using high-quality STM roughness data as input reproduce the measured anisotropies remarkably well and unambiguously relate them to the long-ranged dipolar interactions

Growth and magnetic anisotropies of Fe films deposited on Si(111) using an ultrathin iron silicide template

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Fluoration de fibres de lin pour la fabrication d’éco-composites.

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