5,852 results match your criteria: "12489 Berlin (Germany); Freie Universität Berlin[Affiliation]"

Two-dimensional transition metal dichalcogenides (2D TMDCs) can be combined with organic semiconductors to form hybrid van der Waals heterostructures. Specially, non-fullerene acceptors (NFAs) stand out due to their excellent absorption and exciton diffusion properties. Here, we couple monolayer tungsten diselenide (ML-WSe) with two well performing NFAs, ITIC, and IT-4F (fluorinated ITIC) to achieve hybrid architectures.

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TiCT MXene Thin Films and Intercalated Species Characterized by IR-to-UV Broadband Ellipsometry.

J Phys Chem C Nanomater Interfaces

January 2025

Nanoscale Solid-Liquid Interfaces, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Schwarzschildstraße 8, 12489 Berlin, Germany.

MXenes are two-dimensional (2D) materials with versatile applications in optoelectronics, batteries, and catalysis. To unlock their full potential, it is crucial to characterize MXene interfaces and intercalated species in more detail than is currently possible with conventional optical spectroscopies. Here, we combine ultra-broadband ellipsometry and transmission spectroscopy from the mid-infrared (IR) to the deep-ultraviolet (UV) to probe quantitatively the composition, structure, transport, and optical properties of spray-coated TiCT MXene thin films with varying material properties.

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Herein, we report the solvent-dependent reactivity of Fe(CO) toward AsF in either anhydrous HF or liquid SO. The reaction of Fe(CO) with the superacid HF/AsF leads to the protonation of the iron center and allows for the first-time structural characterization of [FeH(CO)] in the solid state, representing one of the most acidic transition metal hydride complexes to ever be isolated and structurally characterized. In the aprotic but oxidation-stable solvent SO, Fe(CO) is oxidized and dimerized to [Fe(CO)], which is isoelectronic with well-known Mn(CO).

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Oxygen vacancies (V's) are of paramount importance in influencing the properties and applications of ceria (CeO). Yet, comprehending the distribution and nature of V's poses a significant challenge due to the vast number of electronic configurations and intricate many-body interactions among V's and polarons (Ce ions). In this study, we established a cluster expansion model based on first-principles calculations and statistical learning to decouple the interactions among the Ce ions and V's, thereby circumventing the limitations associated with sampling electronic configurations.

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Knowledge of the structure-property relationships of functional nanomaterials, including, for example, their size- and composition-dependent photoluminescence (PL) and particle-to-particle variations, is crucial for their design and reproducibility. Herein, the Angstrom-resolution capability of an analytical ultracentrifuge combined with an in-line multiwavelength emission detection system (MWE-AUC) for measuring the sedimentation coefficient-resolved spectrally corrected PL spectra of dispersed nanoparticles is demonstrated. The capabilities of this technique are shown for giant-shell CdSe/CdS quantum dots (g-QDs) with a PL quantum yield (PL QY) close to unity capped with oleic acid and oleylamine ligands.

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: Idiopathic scoliosis (IS) is a common spinal deformity affecting 0.5% to 5.2% of children worldwide, with a higher reported range in Spain (0.

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Two-dimensional layered double hydroxides (LDHs) are ideal candidates for a large number of (bio)catalytic applications due to their flexible composition and easy to tailor properties. Functionality can be achieved by intercalation of amino acids (as the basic units of peptides and proteins). To gain insight on the functionality, we apply resonant inelastic soft x-ray scattering and near edge x-ray absorption fine structure spectroscopy to CaFe LDH in its pristine form as well as intercalated with the amino acids proline and cysteine to probe the electronic structure and its changes upon intercalation.

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Unveiling the enzymatic pathway of UMG-SP2 urethanase: insights into polyurethane degradation at the atomic level.

Chem Sci

December 2024

LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre s/n 4169-007 Porto Portugal

The recently discovered metagenomic urethanases UMG-SP1, UMG-SP2, and UMG-SP3 have emerged as promising tools to establish a bio-based recycling approach for polyurethane (PU) waste. These enzymes are capable of hydrolyzing urethane bonds in low molecular weight dicarbamates as well as in thermoplastic PU and the amide bond in polyamide employing a Ser-Ser -Lys triad for catalysis, similar to members of the amidase signature protein superfamily. Understanding the catalytic mechanism of these urethanases is crucial for enhancing their enzymatic activity and improving PU bio-recycling processes.

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Increasing attention to sustainability and cost-effectiveness in energy storage sector has catalyzed the rise of rechargeable Zinc-ion batteries (ZIBs). However, finding replacement for limited cycle-life Zn-anode is a major challenge. Molybdenum disulfide (MoS), an insertion-type 2D layered material, has shown promising characteristics as a ZIB anode.

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Phenolic compounds are known for their health-promoting effects on humans. Pak choi (Brassica rapa ssp. chinensis) and Swiss chard (Beta vulgaris subsp.

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Studies on the Virucidal Effects of UV-C of 233 nm and 275 nm Wavelengths.

Viruses

December 2024

Institute of Hygiene and Environmental Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Str., 17475 Greifswald, Germany.

Among the physical decontamination methods, treatment with ultraviolet (UV) radiation is a suitable means of preventing viral infections. Mercury vapor lamps (254 nm) used for room decontamination are potentially damaging to human skin (radiation) and harmful to the environment (mercury). Therefore, other UV-C wavelengths (100-280 nm) may be effective for virus inactivation on skin without damaging it, e.

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The recently developed phenoplast-related polymer, poly(benzofuran--arylacetic acid), presents a versatile molecular structure containing lactone and carboxylic acid functionalities that offer significant flexibility in creating cured materials with tailored properties for diverse applications, wherein also the thermal conductivity is an important factor. This study analyses the possibility of forming amide moieties of poly(benzofuran--arylacetic acid) with diamines resulting in cross-linked products in order to control its thermal properties. The cross-linking process is achieved by utilizing three distinct diamines, 1,6-diaminohexane, -xylylenediamine, and 4,7,10-trioxa-1,13-tridecanediamine, each possessing different degrees of polarity, flexibility, and reactivity.

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Synthesis of Tin Oxide Nanoparticles from E-Waste for Photocatalytic Mixed-Dye Degradation under Sunlight.

ACS Omega

December 2024

Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Chennai Campus, Vandalur-Kelambakkam Road, Chennai, Tamil Nadu 600127, India.

Electronic waste (e-waste) has become a significant environmental concern worldwide due to the rapid advancement of technology and short product lifecycles. Waste-printed electronic boards (WPCBs) contain valuable metals and semiconductors; among them, tin can be recycled and repurposed for sustainable material production. This study presents a potential ecofriendly methodology for the recovery of tin from WPCBs in the form of tin oxide nanostructured powders.

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The rational design of engineered nanomaterials (NMs) with improved functionality and their increasing industrial application requires reliable, validated, and ultimately standardized characterization methods for their application-relevant, physicochemical key properties such as size, size distribution, shape, or surface chemistry. This calls for nanoscale (certified) reference materials (CRMs; RMs) and well-characterized reference test materials (RTMs) termed also quality control (QC) samples, assessed, e.g.

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Pentafluoroorthotellurate Uncovered: Theoretical Perspectives on an Extremely Electronegative Group.

Inorg Chem

January 2025

Departamento de Química Física and Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza 50009, Spain.

Article Synopsis
  • The pentafluoroorthotellurate group (-OTeF, teflate) is a potent electron-withdrawing substitute for fluoride, known for its stability and size, which helps avoid bridging ligand behavior.
  • This study employs advanced Quantum Chemical Topology methods to analyze the electronic structure and bonding of the teflate group, comparing its electronegativity with halogens and investigating the interactions in various XOTeF systems.
  • Findings reveal that while teflate exhibits strong electron-withdrawing abilities akin to fluorine, its bonding is predominantly ionic and shares similar electronegativity traits with other O-donor groups.
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Charge transport in materials has an impact on a wide range of devices based on semiconductor, battery, or superconductor technology. Charge transport in sliding charge density waves (CDW) differs from all others in that the atomic lattice is directly involved in the transport process. To obtain an overall picture of the structural changes associated to the collective transport, the large coherent x-ray beam generated by an x-ray free-electron laser (XFEL) source was used.

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Efficient Electrosynthesis of Hydrogen Peroxide Enabled by a Hierarchical Hollow RE-P-O (RE = Sm, La, Gd) Architecture with Open Channels.

Adv Mater

January 2025

Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, China.

The electrochemical two-electron oxygen reduction reaction (2e ORR) offers a sustainable pathway for the production of HO; however, the development of electrocatalysts with exceptional activity, selectivity, and long-term stability remains a challenging task. Herein, a novel approach is presented to addressing this challenge by synthesizing hierarchical hollow SmPO nanospheres with open channels via a two-step hydrothermal treatment. The produced compound demonstrates remarkable 2e selectivity, exceeding 93% across a wide potential range of 0.

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Dynamic Covalent Spiropyran Exchange for Rapid Structural Diversification.

Angew Chem Int Ed Engl

January 2025

Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.

Here we disclose that spiropyrans are able to undergo dynamic covalent exchange via their corresponding merocyanine isomers. In the latter, the indolinium moieties can be exchanged by a Michael-type addition-elimination sequence, in which a methylene indoline attacks a merocyanine and subsequently the initial indoline fragment is cleaved. The rate and position of the exchange equilibrium strongly depend on the reaction conditions as well as the substitution pattern on the methylene indoline fragments.

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X-ray absorption spectroscopy of FeH to aid its identification in astrochemical environments.

Chem Commun (Camb)

January 2025

Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25/3, 6020 Innsbruck, Austria.

We present the first absorption spectrum of the unperturbed diatomic molecular ion FeH in any wavelength range. The cryogenic X-ray absorption spectrum at the L and L edge is consistent with an iron 3d occupation of 6.24e.

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In this study, we extended a previously developed one-pot double derivatization reaction to establish the first routine isotope-coded multiplex derivatization for vitamin D and its metabolites for application in clinical environments, using commercial reagents, without the need for specialized reagents and advanced synthesis requirements. The original derivatization process consisted of using both a Cookson-type reagent and derivatization of hydroxyl groups. Initially, the analytes are derivatized by a Diels-Alder reaction using 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), followed by acetylation using acetic anhydride, catalyzed by 4-dimethylaminopyridine at room temperature.

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Neuropsychological profiles of patients suffering from hallucinogen persisting perception disorder (HPPD): A comparative analysis with psychedelic-using and non-using controls.

Sci Rep

December 2024

Campus Charité Mitte, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Psychiatric University Clinic at Hospital St. Hedwig, 10115, Berlin, Germany.

Classic psychedelics like LSD and psilocybin are showing promising effects in treating certain psychiatric disorders. Despite their low toxicity and lack of an addictive potential, in some individuals, psychedelics can be associated with persisting psychological harms. Hallucinogen Persisting Perception Disorder (HPPD) is one of those complications, a rare disorder characterized by enduring perceptual symptoms without impaired reality control.

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Metal-Mediated Protein Engineering within Live Cells.

Chem Asian J

December 2024

Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.

Article Synopsis
  • Metal-mediated organic reactions show promise for protein modifications in living cells, which could help target diseases effectively.
  • Metals like Cu(I), Pd, Au(III), and Ru(III) are particularly useful due to their easy handling and ability to penetrate cells.
  • The CuAAC (click reaction) is highlighted as a key method for modifying biomolecules inside cells, offering rapid and specific reactions that are beneficial for therapeutic applications.
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Anodic Activation of Prussian Blue Analog Leads to Highly Active Cobalt-Doped Nickel (Oxy)Hydroxide for Organic Oxidation Reactions.

Chemistry

December 2024

Material Chemistry Group for Thin Film Catalysis, CatLab, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany.

Water-assisted electrocatalytic oxidation of alcohols into valuable chemicals is a promising strategy to circumvent the sluggish kinetics of water oxidation, while also reducing cell voltage and improving energy efficiency. Recently, transition metal (TM)-based catalysts have been investigated for anodic alcohol oxidation, but success has been limited due to competition from the oxygen evolution reaction (OER) within the working regime. In this study, NiCo-based Prussian blue analog (PBA) was electrochemically activated at the anodic potential to produce a Co-Ni(O)OH active catalyst with a nanosheet-like architecture.

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Integrate-and-fire models are an important class of phenomenological neuronal models that are frequently used in computational studies of single neural activity, population activity, and recurrent neural networks. If these models are used to understand and interpret electrophysiological data, it is important to reliably estimate the values of the model's parameters. However, there are no standard methods for the parameter estimation of Integrate-and-fire models.

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Nanoscale polarization transient gratings.

Nat Commun

December 2024

Elettra - Sincrotrone Trieste S.C.p.A., S.S. 14 km 163.5 in Area Science Park, 34149, Trieste, Italy.

Light manipulation at the nanoscale is essential both for fundamental science and modern technology. The quest to shorter lengthscales, however, requires the use of light wavelengths beyond the visible. In particular, in the extreme ultraviolet regime these manipulation capabilities are hampered by the lack of efficient optics, especially for polarization control.

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