A5053008851- Semiconductor materials and devices
- Advancements in Battery Materials
- Gas Sensing Nanomaterials and Sensors
- Analytical Chemistry and Sensors
- Nanofabrication and Lithography Techniques
- Polymer Surface Interaction Studies
- Hepatitis B Virus Studies
- Molecular Junctions and Nanostructures
- Ion-surface interactions and analysis
- Thin-Film Transistor Technologies
- Electron and X-Ray Spectroscopy Techniques
- Diamond and Carbon-based Materials Research
- Conducting polymers and applications
- ZnO doping and properties
- Advanced Chemical Sensor Technologies
- Viral Infections and Outbreaks Research
- Civil and Structural Engineering Research
- Concrete Corrosion and Durability
- Flexible and Reconfigurable Manufacturing Systems
- Advanced ceramic materials synthesis
- Advanced Battery Technologies Research
- Advanced Battery Materials and Technologies
- Metal and Thin Film Mechanics
- Supercapacitor Materials and Fabrication
- Animal Virus Infections Studies
Canisius-Wilhelmina Ziekenhuis
2024
Karlsruhe Institute of Technology
2014-2023
University of Hildesheim
2023
Max Planck Institute for Solar System Research
2023
Universität Hamburg
2002-2022
HAW Hamburg
2022
Dr. August Wolff (Germany)
2009-2021
Leibniz Institute of Virology (LIV)
2006-2021
University Medical Center Hamburg-Eppendorf
2020-2021
Deutsches Institut für Bautechnik (Germany)
2021
Mixed bimetallic oxides offer great opportunities for a systematic tuning of electrocatalytic activity and stability. Here, we demonstrate the power this strategy using well-defined thermally prepared Ir-Ni mixed oxide thin film catalysts electrochemical oxygen evolution reaction (OER) under highly corrosive conditions such as in acidic proton exchange membrane (PEM) electrolyzers photoelectrochemical cells (PEC). Variation Ir to Ni ratio resulted volcano type OER curve with an unprecedented...
Abstract A facile strategy to synthesize water‐soluble fluorescent gold nanoclusters (Au NCs) stabilized with the bidentate ligand dihydrolipoic acid (DHLA) is reported. The DHLA‐capped Au NCs are characterized by UV–vis absorption spectroscopy, fluorescence transmission electron microscopy, and X‐ray photoelectron spectroscopy. possess many attractive features including ultrasmall size, bright near‐infrared luminescence, high colloidal stability, good biocompatibility, making them promising...
We present highly efficient electroluminescent devices using size-separated silicon nanocrystals (ncSi) as light emitting material. The emission color can be tuned from the deep red down to yellow-orange spectral region by very monodisperse nanoparticles. High external quantum efficiencies up 1.1% well low turn-on voltages are obtained for emitters. In addition, we demonstrate that size-separation of ncSi leads drastically improved lifetimes and much less sensitivity wavelength applied drive voltage.
We report a facile strategy to synthesize water-soluble, fluorescent gold nanoclusters (AuNCs) in one step by using mild reductant, tetrakis(hydroxymethyl)phosphonium chloride (THPC). A zwitterionic functional ligand, D-penicillamine (DPA), as capping agent endowed the AuNCs with excellent stability aqueous solvent over physiologically relevant pH range. The DPA-capped displayed excitation and emission bands at 400 610 nm, respectively; fluorescence quantum yield was 1.3%. effect of...
A microwave-assisted strategy for synthesizing dihydrolipoic acid (DHLA) capped fluorescent gold nanoclusters (AuNCs) has been developed. Irradiation with microwaves during synthesis enhanced the fluorescence quantum yield (QY) of AuNCs by about five-fold and shortened reaction time from hours to several minutes. The as-synthesized DHLA-AuNCs possessed bright near-infrared (QY: 2.9%), ultrasmall hydrodynamic diameter (3.3 nm), good colloidal stability over physiologically relevant pH range...
A long-term mountain station series of tropospheric 14 C data for the period 1959 to 1984 is presented. This considered representative higher altitude level over central Europe. Even tree-ring levels from a rural ground site in southern Germany are consistently lower (by Δ depression = −15‰ if compared with summer average atmospheric CO 2 ). The represent additional continental Suess effect at without local contamination. decreases gradually distance ( ie , source) level. We therefore...
Bioinspired poly(dopamine) (PDA) films are merged with antifouling poly(MeOEGMA) brushes utilizing a nitrile imine-mediated tetrazole-ene cycloaddition (NITEC)-based phototriggered surface encoding protocol. The were photopatterned on PDA surfaces, leading cells to form confluent layers in the non-irradiated sections, while no adhesion occurred resulting remarkably precise cell pattern. presented strategy paves way for design of tailor-made patterned interfaces. As service our authors and...
A photoconjugation strategy based on light-triggered Diels–Alder addition of o-quinodimethanes is compatible with biomolecules and proceeds rapidly at ambient temperature without the need a catalyst. Spatial control was confirmed by photopatterning small-molecule ATRP initiator, polymer, peptide in time-of-flight secondary-ion mass spectrometry investigation.
The interaction of proteins with ultrasmall gold nanoclusters (Au NCs) is investigated. Upon protein association, the fluorescence Au NCs significantly enhanced and, concomitantly, their luminescence lifetime prolonged. results stress importance investigating behavior fluorescent metal in complex biological environment for advancing bio-nanotechnology applications.
Inverted device architectures for organic light-emitting diodes (OLEDs) require suitable interfaces or buffer layers to enhance electron injection from highwork-function transparent electrodes. A solution-processable combination of ZnO and PEI is reported, that facilitates enables efficient air-stable inverted devices. Replacing the metal anode by highly conductive polymers OLEDs.
Abstract The nitrile imine‐mediated tetrazole‐ene cycloaddition reaction (NITEC) is introduced as a powerful and versatile conjugation tool to covalently ligate macromolecules onto variable (bio)surfaces. NITEC approach initiated by UV irradiation proceeds rapidly at ambient temperature yielding highly fluorescent linkage. Initially, the formation of block copolymers methodology studied evidence its efficacy macromolecular tool. grafting polymers inorganic (silicon) bioorganic (cellulose)...
Amorphous silicon is a promising high-capacity anode material for the next generation of lithium-ion batteries. However, enormous volume expansion active during lithiation up to 400% (V/V0) held responsible capacity fading cycling. In this study we measured continuously modifications taking place galvanostatic amorphous thin film electrodes by in-operando neutron reflectometry experiments. The results indicate (after initial effects) linear increase in as function time and lithium content...
Fully solution processed monochromatic and white-light emitting tandem or multi-photon polymer OLEDs with an inverted device architecture have been realized by employing WO3 /PEDOT:PSS/ZnO/PEI charge carrier generation layers. The luminance of the sub-OLEDs adds up in stacked indicating emission. white exhibit a CRI 75.
The detailed characterization of garnet-type Li-ion conducting Li7La3Zr2O12 (LLZO) solid electrolyte thin films grown by novel CO2-laser assisted chemical vapor deposition (LA-CVD) is reported. A process parameter study reveals that an optimal combination temperature and oxygen partial pressure essential to obtain high quality tetragonal LLZO films. polycrystalline on platinum have a dense homogeneous microstructure are free cracks. total lithium ion conductivity 4.2·10−6 S·cm−1 at room...
Making light work of ligation: A novel method utilizes for oxime ligation chemistry. quantitative, low-energy photodeprotection generates aldehyde, which subsequently reacts with aminooxy moieties. The spatial control allows patterning on surfaces a fluoro marker and GRGSGR peptide, can be imaged by time-of-flight secondary-ion mass spectrometry.
Abstract As promising cathode materials, the lithium‐excess 3d‐transition‐metal layered oxides can deliver much higher capacities (>250 mAh g −1 at 0.1 C) than current commercial oxide materials (≈180 used in lithium ion batteries. Unfortunately, original formation mechanism of these during synthesis is not completely elucidated, that is, how and oxygen inserted into matrix structure precursor lithiation reaction? Here, a practical method, coprecipitation route followed by microwave...
MXenes, two-dimensional transition metal carbides or nitrides, have recently shown great promise for gas sensing applications. We demonstrate that the sensitivity of intrinsically metallic Ti3C2Tx MXene can be considerably improved via its partial oxidation in air at 350 °C. The annealed films sheets remain electrically conductive, while their decoration with semiconducting TiO2 improves chemiresistive response to organic analytes low-ppm concentrations dry air, which was used emulate...
Zinc stannate (Zn2SnO4) nanoparticles with an average size of about 26 nm are synthesized via single-step mechanochemical processing binary oxide precursors (ZnO and SnO2) at ambient temperature, without the need for subsequent calcination, thus making synthesis route very simple cost-effective. The mechanically induced phase evolution 2ZnO + SnO2 mixture is followed by XRD a variety spectroscopic techniques including 119Sn MAS NMR, Raman spectroscopy, Mössbauer XPS. High-resolution TEM...
Abstract The photocatalytic activity of TiO 2 under sunlight irradiation depends on the bandgap energy. Due to relatively low solar intensity in UV region (<10%) and fact that is usually greater than 3 eV (below 400 nm), many attempts have been made shift towards lower energies. Here, we investigate structure, chemical composition, charge transfer processes Ag@TiO core‐shell nanoparticle thin films by field emission scanning electron microscopy, atomic force XPS, UV‐Vis spectroscopy. As a...