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Amino acid-based complexing agents for improved Zn anode performance in near-neutral aqueous Zn-air batteries
No full textAqueous electrolytes used in zinc–air batteries often face issues with low stability and unwanted side reactions, especially under alkaline conditions. This highlights the need for alternative electrolyte systems, such as near-neutral electrolytes. In this study, we explore the innovative use of amino-acid–based complexing agents, specifically glycine (Gly) and iminoacetic acid (IDA), to enhance the performance of Zn electrodes in a 2 M NaCl electrolyte. Unlike traditional additives, these amino acids serve a muti purpose: they coordinate with Zn²⁺ ions in the bulk electrolyte and simultaneously regulate the interface between Zn and the electrolyte, while providing pH stability. Density functional theory (DFT) calculations indicate that this unique interaction alters the solvation shell of Zn²⁺, which helps reduce the formation of a passivation layer. In-operando X-ray computed tomography (XCT) further demonstrates that the amino-acid additives facilitate uniform Zn deposition and improve the cycling stability of the plating and stripping process. This work highlights the significance of solvation shell modulation in optimizing electrochemical performance and offers valuable insights for the development of near-neutral electrolyte-based Zn-air batteries
Individual and simultaneous encapsulation and delivery of incompatible dyes in biocompatible multicompartment terpolymer micelles
No full textManaging conflicting interests in subsidy design: A bi-level optimization approach for heating technology subsidies
No full textA micromechanical investigation of plasticity in ordered NbMoCrTiAl and disordered TaNbHfZrTi refractory compositionally complex alloys at room temperature
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Thermodynamics of Organic Acid Sorption to Goethite
No full textAdsorption to minerals is a key mechanism in stabilizing organic carbon in soils. We used isothermal titration calorimetry (ITC) to quantify the thermodynamics of binding of citric acid, oxalic acid, and salicylic acid to four goethites with different specific surface areas (SSA, 14–120 m2 g−1). Thermodynamic parameters could be determined for sorption of citric and salicylic acids, while flocculation of particles prevented their quantification for sorption of oxalic acid. For citric acid adsorption, ∆H shifted from −23.5 ± 0.57 to −27.0 ± 0.47 kJ mol−1 and ∆S from −8.8 ± 1.54 to −29.9 ± 0.13 J mol−1 K−1 with increasing SSA and broader (110) diffraction peaks of goethite, thus reducing ∆G from −20.7 ± 0.02 to −18.0 ± 0.03 kJ mol−1. Salicylic acid adsorption was more exothermic (∆H −40.53 ± 1.93 kJ mol−1) and accompanied by a larger loss of entropy (∆S −65.1 ± 1.91 J mol−1 K−1), possibly due to chelation of its ortho hydroxyl and carboxyl groups to single iron atoms on the mineral surface. These results demonstrate that ITC can decipher adsorption thermodynamics of organic ligands to mineral surfaces, but ligand-induced flocculation can render the interpretation of results difficult. Crystallite size and lattice defects of adsorbent minerals influence the thermodynamics of sorption by determining the conformation of organic molecules sorbed to goethite surfaces
Development and validation of a new ozone dataset using Complete Data Fusion of MIPAS and IASI observations: a step towards understanding stratospheric ozone intrusions
No full textTi-Nb alloy coatings for anode PTLs in PEM water electrolyzers
No full textOne of the most cost-intensive components of proton exchange membrane water electrolyzers (PEMWE) are the anode-side Porous Transport Layers (PTLs), often comprised of titanium with a noble metal coating such as platinum. Replacing the noble metal coating is crucial to reduce the manufacturing costs of PEM electrolyzers. This study aims to replace conventional platinum coatings with titanium-niobium alloy coatings using magnetron sputtering. To evaluate the performance and stability of the coated PTLs, laboratory-scale tests have been conducted with PEMWE single cells. Post-mortem analysis of the PTLs included scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and resistance measurements. So far, the best results were achieved with alloy coatings consisting of 94 at.% titanium and 6 at.% niobium, as these coatings enabled stable PEMWE operation for 144 h at 2.0 V. TEM confirms that niobium is incorporated into the growing oxide scale. We assume that the pentavalent niobium atoms serve as donator sites in the oxide increasing its electric conductivity
Evaluation of excitation functions of 127I(p,xn) 121,122, 123, 125,127Xe reactions, with particular reference to the production of 127Xe and 123I for medical use
No full textCross section data for the formation of 121,122,123,125,127Xe via proton induced reactions on 127I were criticallyanalyzed. Three nuclear model codes (TALYS 1.9, ALICE-IPPE, and EMPIRE 3.2) were used to ensure the con-sistency and reliability of the experimental data. Utilizing a well-developed evaluation methodology, a recom-mended fit for each excitation function was obtained, based on theoretical predictions of nuclear models andexperimental cross sections. By using the recommended/reference results, thick target yields were calculated foreach production route and its associated impurity reactions. The indirect production of the radionuclides121,122,123,125I was explored. Special attention was paid to standardization of cross section data for the productionof the medically important radionuclides 127Xe and 123I via the routes 127I(p,n)127Xe and 127I(p,5n)123Xe(EC,β+)123I, respectively
Exploring the Anion Site Disorder Kinetics in Lithium Argyrodites
No full textLithium argyrodites are a promising class of solid-state electrolytes with the potential to achieve high conductivities (>10 necessary for use in solid-state batteries. Previous research has shown that structural factors, in particular, site disorder between the sulfide and halide anions, can impact the ionic conductivity of lithium argyrodites. One current hypothesis for this correlation between anion site disorder and ionic transport is a connection to the lithium-ion substructure. However, as there is limited research surrounding the anion disordering process itself, this relationship has yet to be fully understood. This research explores the impact of the composition and synthesis on the anion disordering process through the ( = 0 to 0.4 in 0.1 steps) series of substitutions quenched from different annealing temperatures. Ex situ and in situ diffraction studies show that the anion site disorder within the compounds increases upon Si introduction only for samples quenched from higher annealing temperatures but remains relatively constant at lower annealing temperatures. Based on in situ diffraction measurements, we further monitor the effects of anion mobility at elevated temperatures allowing inference of slower anion disordering kinetics with changing compositional content. We complement the experimental work using nudged-elastic band calculations showing the overall preference of anions for their specific sites and the possibility of anion mobility. This work provides insight into the argyrodites and shows that the anion disordering can be monitored and that the composition has strong influences on the disordering process