93 research outputs found
Ionized Jet Deposition of MoS2 on Gas Diffusion Layer Electrodes for Next Generation Alkaline Electrolyzers
No full textThis study focuses on optimizing MoS2 catalysts for the hydrogen evolution reaction (HER) in anion exchange membrane (AEM) electrolyzers. A scalable Ionized Jet Deposition (IJD) technique is employed to deposit MoS2 onto various carbon supports, exploring the relationship between substrate properties and catalytic performance. The results demonstrate that substrate choice plays a pivotal role in enhancing HER activity and durability. MoS2 deposited on Freudenberg carbon support exhibited the best catalytic activity, achieving a current density of 10 mA mu g(-)(1)Mo at -0.48 V versus RHE in an alkaline environment, even with a low catalyst loading (12-49 mu g cm(-)(2)). Conversely, sulfur-doped carbon supports showed lower HER activity but superior stability, with a minimal voltage degradation of just 0.025 V after 6 h of testing at 10 mA cm(-)(2). To further understand these results, bubble evolution studies, and contact angle measurements are conducted. Stable electrodes demonstrated small contact angles and enhanced bubble release from the surface, indicating the importance of hydrophilicity in improving performance and durability. This work highlights the synergy between scalable synthesis techniques and substrate optimization, offering a promising path for advancing cost-efficient, durable electrocatalysts in large-scale AEM electrolyzers for green hydrogen production
“Conformational Self-Recognition as the Origin of Dewetting in Bistable Molecular Surfaces”
No full textA novel combined experimental and multiscale theoretical approach to unravel the structure of SiC/SiO: Xcore/shell nanowires for their optimal design
No full textIn this work we propose a realistic model of nanometer-thick SiC/SiOxcore/shell nanowires (NWs) using a combined first-principles and experimental approach. SiC/SiOxcore/shell NWs were first synthesised by a low-cost carbothermal method and their chemical-physical experimental analysis was accomplished by recording X-ray absorption near-edge spectra. In particular, the K-edge absorption lineshapes of C, O, and Si are used to validate our computational model of the SiC/SiOxcore/shell NW architectures, obtained by a multiscale approach, including molecular dynamics, tight-binding and density functional simulations. Moreover, we present ab initio calculations of the electronic structure of hydrogenated SiC and SiC/SiOxcore/shell NWs, studying the modification induced by several different substitutional defects and impurities into both the surface and the interfacial region between the SiC core and the SiOxshell. We find that on the one hand the electron quantum confinement results in a broadening of the band gap, while hydroxyl surface terminations decrease it. This computational investigation shows that our model of SiC/SiOxcore/shell NWs is capable to deliver an accurate interpretation of the recorded X-ray absorption near-edge spectra and proves to be a valuable tool towards the optimal design and application of these nanosystems in actual devices
Correction: Functionalization of SiC/SiOX nanowires with a porphyrin derivative: A hybrid nanosystem for X-ray induced singlet oxygen generation (Molecular Systems Design and Engineering (2017) DOI: 10.1039/c7me00005g)
No full textThe authors regret an error in the name of the 5th author which was incorrectly shown as R. Rossi instead of F. Rossi. The corrected list of authors and affiliations for this paper is shown here. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers
Neue technologische Möglichkeiten für die Prävention. AnkerSteps – eine intelligente App für mehr Bewegung.
No full textTechnologien wie E-Health, Big Data und soziale Netzwerke eröffnen neue Möglichkeiten zur Prävention von Typ-2-Diabetes. Forscher des Universitätsklinikums Carl Gustav Carus in Dresden arbeiten an der Entwicklung von Präventionsprodukten, die ein breites Segment in der Bevölkerung erreichen können und einen gesunden Lebensstil unterstützen. Ein Beispiel ist die App „AnkerSteps“. Sie motiviert die Nutzer, sich 10 000 Schritte am Tag zu bewegen. Die Entwicklung solcher intelligenter Apps bringt Experten und Leistungserbringer näher an die Risikoperson als je zuvor.  
Tuning the Work Function of Graphene-on-Quartz with a High Weight Molecular Acceptor
No full textUltraviolet and X-ray photoelectron spectroscopies in combi- nation with density functional theory (DFT) calculations were used to study the change in the work function (Φ) of graphene, supported by quartz, as induced by adsorption of hexaazatriphenylene−hexacarbonitrile (HATCN). Near edge X-ray absorption fine structure spectroscopy (NEXAFS) and DFT modeling show that a molecular-density-dependent reorientation of HATCN from a planar to a vertically inclined adsorption geometry occurs upon increasing surface coverage. This, in conjunction with the orientation- dependent magnitude of the interface dipole, allows one to explain the evolution of graphene Φ from 4.5 eV up to 5.7 eV, rendering the molecularly modified graphene-on-quartz a highly suitable hole injection electrode
2D-MoS2 goes 3D: transferring optoelectronic properties of 2D MoS2 to a large-area thin film
No full textAbstract The ongoing miniaturization of electronic devices has boosted the development of new post-silicon two-dimensional (2D) semiconductors, such as transition metal dichalcogenides, one of the most prominent materials being molybdenum disulfide (MoS2). A major obstacle for the industrial production of MoS2-based devices lies in the growth techniques. These must ensure the reliable fabrication of MoS2 with tailored 2D properties to allow for the typical direct bandgap of 1.9 eV, while maintaining large-area growth and device compatibility. In this work, we used a versatile and industrially scalable MoS2 growth method based on ionized jet deposition and annealing at 250 °C, through which a 3D stable and scalable material exhibiting excellent electronic and optical properties of 2D MoS2 is synthesized. The thickness-related limit, i.e., the desired optical and electronic properties being limited to 2D single/few-layered MoS2, was overcome in the thin film through the formation of encapsulated highly crystalline 2D MoS2 nanosheets exhibiting a bandgap of 1.9 eV and sharp optical emission. The newly synthesized 2D-in-3D MoS2 structure will facilitate device compatibility of 2D materials and confer superior optoelectronic device function
Wirksamkeit einer gamification-basierten Smartphone-Applikation zur Gewichtsreduzierung bei Kindern und Jugendlichen mit Übergewicht und Adipositas- Studienprotokoll für eine randomisierte kontrollierte Studie
No full textOligothiophene‐Based Phosphonates for Surface Modification of Ultraflat Transparent Conductive Oxides
No full textThe self-assembly of electroactive organic molecules on transparent conductive oxides is a versatile strategy to engineer the interfacial energy- level alignment and to enhance charge carrier injection in optoelectronic devices. Via chemical grafting of an aromatic oligothiophene molecule
by changing the position of the phosphonic acid anchoring group with respect to the organic moiety (terminal and internal), the direction of the main molecular dipole is changed, i.e., from parallel to perpendicular to the substrate, to study the molecular arrangement and electronic properties at the organic–inorganic interface. It is found that the observed work function increase cannot solely be predicted based on the calculated molecular dipole moment of the oligothiophene-based phosphonates. In addition, charge transfer from the substrate to the molecule has to be taken into account. Molecular assembly and induced electronic changes are analogous for both indium-tin oxide (ITO) and zinc oxide (ZnO), demonstrating the generality of the approach and highlighting the direct correlation between molecular coverage and electronic effects
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