11. Effect of the Morphology of the High-Surface-Area Support on the Performance of the Oxygen-Evolution Reaction for Iridium NanoparticlesLeonard Moriau, Marjan Bele, Živa Marinko, Francisco Ruiz-Zepeda, Gorazd Koderman, Martin Šala, Angelija Kjara Šurca, Janez Kovač, Iztok Arčon, Primož Jovanovič, Nejc Hodnik, Luka Suhadolnik, 2021, original scientific article Abstract: The development of affordable, low-iridium-loading,
scalable, active, and stable catalysts for the oxygen-evolution
reaction (OER) is a requirement for the commercialization of
proton-exchange membrane water electrolyzers (PEMWEs).
However, the synthesis of high-performance OER catalysts with
minimal use of the rare and expensive element Ir is very challenging
and requires the identification of electrically conductive and stable
high-surface-area support materials. We developed a synthesis
procedure for the production of large quantities of a nanocomposite
powder containing titanium oxynitride (TiONx) and Ir.
The catalysts were synthesized with an anodic oxidation process
followed by detachment, milling, thermal treatment, and the
deposition of Ir nanoparticles. The anodization time was varied to grow three different types of nanotubular structures exhibiting different lengths and wall thicknesses and thus a variety of properties. A comparison of milled samples with different degrees of nanotubular clustering and morphology retention, but with identical
chemical compositions and Ir nanoparticle size distributions and dispersions, revealed that the nanotubular support morphology is
the determining factor governing the catalyst’s OER activity and stability. Our study is supported by various state-of-the-art
materials’ characterization techniques, like X-ray photoelectron spectroscopy, scanning and transmission electron microscopies, Xray powder diffraction and absorption spectroscopy, and electrochemical cyclic voltammetry. Anodic oxidation proved to be a very suitable way to produce high-surface-area powder-type catalysts as the produced material greatly outperformed the IrO2 benchmarks
as well as the Ir-supported samples on morphologically different TiONx from previous studies. The highest activity was achieved for the sample prepared with 3 h of anodization, which had the most appropriate morphology for the effective removal of oxygen
bubbles. Keywords: electrocatalysis, oxygen-evolution reaction, TiONx-Ir powder catalyst, iridium nanoparticles, anodic oxidation, morphology−activity correlation Published in RUNG: 04.01.2021; Views: 2599; Downloads: 0 This document has many files! More... |
12. Effect of Aerosolization and Drying on the Viability of Pseudomonas syringae CellsMalin Alsved, Stine Holm, Sigurd Christiansen, Mads Smidt, Meilee Ling, Thomas Boesen, Kai Finster, Merete Bilde, Jakob Löndahl, Tina Šantl Temkiv, 2018, original scientific article Keywords: bioaerosols, aerosolization, Pseudomonas syringae, drying, bubble bursting, ice nucleation activity Published in RUNG: 04.01.2021; Views: 2203; Downloads: 62 Full text (5,02 MB) |
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14. Aeolian dispersal of bacteria in southwest Greenland: their sources, abundance, diversity and physiological statesTina Šantl Temkiv, Ulrich Gosewinkel, Piotr Starnawski, Mark Lever, Kai Finster, 2018, original scientific article Keywords: arctic microbial communities, aeolian dispersal, community assembly, 16S ribosomal RNA, microbial activity, atmospheric processes Published in RUNG: 04.01.2021; Views: 2488; Downloads: 0 This document has many files! More... |
15. Airborne Microalgae: Insights, Opportunities, and ChallengesSylvie V. M. Tesson, Carsten Ambelas Skjøth, Tina Šantl Temkiv, Jakob Löndahl, 2016, review article Keywords: Airborne microalgae, health effects, ice-nucleation activity, microalgae dispersal Published in RUNG: 04.01.2021; Views: 2297; Downloads: 0 This document has many files! More... |
16. High-Flow-Rate Impinger for the Study of Concentration, Viability, Metabolic Activity, and Ice-Nucleation Activity of Airborne BacteriaTina Šantl Temkiv, Pierre Amato, Ulrich Gosewinkel, Runar Thyrhaug, Anaïs Charton, Benjamin Chicot, Kai Finster, Gunnar Bratbak, Jakob Löndahl, 2017, original scientific article Keywords: Bioaerosols, bioaerosol sampling, impingment, activty studies, ice-nucleation activity, airborne microorganisms Published in RUNG: 04.01.2021; Views: 2433; Downloads: 0 This document has many files! More... |
17. Hailstones: A Window into the Microbial and Chemical Inventory of a Storm CloudTina Šantl Temkiv, Kai Finster, Thorsten Dittman, Bjarne Munk Hansen, Runar Thyrhaug, Niels Woetmann Nielsen, Ulrich Gosewinkel, 2013, original scientific article Keywords: atmospheric bacteria, atmospheric DOM, cloud microbiota, microbial activity Published in RUNG: 04.01.2021; Views: 2566; Downloads: 64 Full text (402,78 KB) |
18. Potent and selective in vitro and in vivo antiproliferative effects of metal-organic trefoil knotsFarah Benyettou, Thirumurugan Prakasam, Anjana Ramdas Nair, Ini-Isabee Witzel, Marwa Alhashimi, Tina Škorjanc, John-Carl Olsen, Kirsten C. Sadler, Ali Trabolsi, original scientific article Keywords: trefoil knot, anticancer activity Published in RUNG: 02.09.2020; Views: 2355; Downloads: 0 This document has many files! More... |
19. The multi-purpose role of hairiness in the lichens of coastal environments: Insights from Seirophora villosa (Ach.) FrödénElisabetta Bianchi, Renato Benesperi, Ilaria Colzi, Andrea Coppi, Lorenzo Lazzaro, Luca Paoli, Alessio Papini, Sara Pignattelli, Corrado Tani, Pamela Vignolini, Cristina Gonnelli, 2019, original scientific article Abstract: The fruticose epiphytic lichen Seirophora villosa, strictly associated with Juniperus shrublands in the
Mediterranean basin, was used to investigate the role of hairiness on a lichen thallus, as a characteristic morphological
trait. We evaluated the effect of hair removal on the physiological parameters of a set of samples,
during desiccation and on exposure to different salt concentrations. Hairy thalli were less affected by salt,
suggesting that during dehydration, the presence of hair protects the thallus from light irradiance, oxidative
stresses and the lipid peroxidation generated by free radicals, and could offer passive, but selective, water
control. Our results showed that hair could not only increase thallus surface and promote water absorption when
availability is low, but could also repel the salt dissolved in water by activating a passive resistance mechanism,
by preventing salt entering. Keywords: Antioxidant activity
Chlorophyll a fluorescence
Juniperus shrublands
Hair
MDA
Salt stress Published in RUNG: 20.04.2020; Views: 2756; Downloads: 0 This document has many files! More... |
20. Improved photocatalytic activity of anatase-rutile nanocomposites induced by low-temperature sol-gel Sn-modification of TiO2Ksenija Maver, Iztok Arčon, Urška Lavrenčič Štangar, Mattia Fanetti, Saim Emin, Matjaž Valant, 2020, original scientific article Abstract: The Sn-modified TiO2 photocatalysts are prepared by low-temperature sol-gel processing based on organic titanium
and tin precursors with varied Sn concentrations (from 0.1–20 mol .%). The role of Sn dopant as the
promotor of the formation of TiO2 rutile crystalline phase is explained and the optimal Sn concentration for
preparation of efficient Sn-modified titania photocatalyst is determined. Up to 40 % increase in photocatalytic
activity is achieved in Sn-modified TiO2 photocatalytic thin films dried at 150 °C with low Sn concentrations in
the range from 0.1 to 1 mol .%. At low Sn concentrations optimal ratio between anatase and rutile (nano)crystals
is obtained, which facilitates charge separation at the TiO2 photocatalyst’s surface. When the concentration of Sn
increases above 5 mol.% or when the films are calcined at 500 °C, the relative amount of rutile phase with
inferior photocatalytic activity, increases and the nanocrystals of titania grow, leading to fewer active sites per
unit mass and the reduction of activity in comparison to unmodified TiO2. Keywords: Anatase-rutile
Sn-modified TiO2
XAS analysis
Photocatalytic activity Published in RUNG: 10.02.2020; Views: 3048; Downloads: 0 This document has many files! More... |