A5090202438- Advanced Materials Characterization Techniques
- Diamond and Carbon-based Materials Research
- Advanced Thermoelectric Materials and Devices
- nanoparticles nucleation surface interactions
- Electronic and Structural Properties of Oxides
- CO2 Reduction Techniques and Catalysts
- Electrocatalysts for Energy Conversion
- Minerals Flotation and Separation Techniques
- Force Microscopy Techniques and Applications
- High Entropy Alloys Studies
- Catalytic Processes in Materials Science
- Ion-surface interactions and analysis
- Fuel Cells and Related Materials
- Magnetic and transport properties of perovskites and related materials
- Advancements in Solid Oxide Fuel Cells
- High Temperature Alloys and Creep
- Metal and Thin Film Mechanics
- Ionic liquids properties and applications
- Analytical chemistry methods development
- Chalcogenide Semiconductor Thin Films
- Advanced materials and composites
- Semiconductor materials and interfaces
- Hydrogen embrittlement and corrosion behaviors in metals
- Intermetallics and Advanced Alloy Properties
- Thermal properties of materials
Korea Advanced Institute of Science and Technology
2019-2024
University of Bayreuth
2024
Max-Planck-Institut für Nachhaltige Materialien
2024
Ceria (CeO2 ) is one of the most extensively used rare earth oxides. Recently, it has been as a support material for metal catalysts electrochemical energy conversion. However, to date, nature metal/CeO2 interfaces and their impact on processes remains unclear. Here, Cu-CeO2 nanorod CO2 reduction catalyst presented. Using operando analysis computational techniques, found that, application reductive potential, Cu undergoes an abrupt change in solubility ceria matrix converting from less...
The development of Cu-based catalysts for electrochemical CO2 reduction reaction (CO2RR) with stronger CO-binding elements had been unsuccessful in improving multicarbon production from the CO2RR due to CO-poisoning. Here, we discover that trace doping levels Co atoms Cu, termed CoCu single-atom alloy (SAA), achieve up twice formation rate CO as compared bare Cu and further demonstrate a high jC2H4 282 mA cm–2 at −1.01 VRHE neutral electrolyte. From DFT calculations, sites neighboring...
Schematic representation of possible oxygen electrochemical reduction pathways self-assembled multi-phase cathodes with a synergistic ensemble effect.
Atom probe tomography requires needle-shaped specimens with a diameter typically below 100 nm, making them both very fragile and reactive, defects (notches at grain boundaries or precipitates) are known to affect the yield data quality. The use of conformal coating directly on sharpened specimen has been proposed increase reduce background. However, date, these coatings have applied ex situ mostly not uniform. Here, we report controlled focused-ion beam in deposition thin metal film...
Capping ligands are crucial to synthesizing colloidal nanoparticles with functional properties. However, the synergistic effect between different and their distribution on crystallographic surfaces of during synthesis is still unclear despite powerful spectroscopic techniques, due a lack direct imaging techniques. In this study, atom probe tomography adopted investigate three-dimensional atomic-scale two most common types these ligands, cetrimonium (C
Abstract Dopant‐induced microstructure in thermoelectric materials significantly affects properties and offers a potential to break the interdependence between electron phonon transport properties. However, identifying all‐scale dopant‐induced microstructures correlating them with remain huge challenge owing lack of detailed microstructural characterization encompassing all length scales. Here, hierarchical boron (B)‐induced B‐doped Si 80 Ge 20 alloys different B concentrations are...
Abstract The performance of thermoelectric materials is typically assessed using the dimensionless figure merit, zT . Increasing challenging due to intricate relationships between electrical and thermal transport properties. This study focuses on Y 2 Te 3 ‐based materials, which are predicted be promising for high‐temperature applications their inherently low lattice conductivity. A series 2+ x compositions with excess synthesized explore effects electronic structural characteristics....
Electrochemical CO2 Reduction In article number 2208996, Pyuck-Pa Choi, Stefan Ringe, Jihun Oh, and co-workers report the synthesis of Cu–ceria-nanorod catalysts for electrochemical reduction. The ceria nanorods help CuO exist as several cluster layers at interface. Through strong metal–support interaction between Cu ceria, can be stably loaded on in a mixed oxidation state Cu/ceria interface, which facilitates CO–CO dimerization, resulting high-efficiency selective ethylene production.
We report on the rapid alloy screening of Ni–Co–Ti–Al–Mo superalloys with high thermal stability and specific yield stress by means directed energy deposition. A laser deposition, a type additive manufacturing, was employed using multiple powder feeders elemental powders. Fifty different compositions were deposited heat-treated microstructure γ' solvus temperature examined. The 43Ni–38Co–9Ti–6Al–4Mo superalloy (atomic percent composition) exhibited uniform γ/γ' 1202 °C. beneficial properties...
Heat treatment-induced nanocrystallization of amorphous precursors is a promising method for nanostructuring half-Heusler compounds as it holds significant potential in the fabrication intricate and customizable nanostructured materials. To fully exploit these advantages, comprehensive understanding crystallization behavior under different conditions crucial. In this study, we investigated NbCo1.1Sn alloy at elevated temperatures (783 893 K) using transmission electron microscopy atom probe...
Atom probe tomography requires needle-shaped specimens with a diameter typically below 100 nm, making them both very fragile and reactive, defects (notches at grain boundaries or precipitates) are known to affect the yield data quality. The use of conformal coating directly on sharpened specimen has been proposed increase reduce background. However, date, these coatings have applied ex-situ mostly not uniformly. Here, we report controlled focused ion beam in-situ deposition thin metal film...
Abstract Carbon-supported nanoparticles have been used widely as efficient catalysts due to their enhanced surface-to-volume ratio. To investigate structure–property relationships, acquiring 3D elemental distribution is required. Here, carbon-supported Pt, PtMn alloy, and ordered Pt3Mn are synthesized analyzed with atom probe tomography model systems. A significant difference of Mn after the heat-treatment was found. Finally, field evaporation behavior carbon support discussed each acquired...
Atomic mapping of nanomaterials, in particular nanoparticles, using atom probe tomography (APT) is great interest, as their properties strongly depend on shape, size, and composition. However, APT analyses nanoparticles are extremely challenging, there an urgent need for developing robust universally applicable sample preparation methods. Herein, we explored a method based pulse electrodeposition to embed Ag Ni matrix prepare specimens from the resulting composite film. By systematically...
Abstract Surface cation segregation, specifically strontium (Sr), has been identified as a primary factor contributing to the performance degradation of perovskite-based oxide electrodes used in various energy conversion devices. However, due complex chemistry and structure perovskite surfaces, mechanisms behind Sr segregation its impact on electrode activity are only partially understood. Moreover, already occurs during synthesis, further complicating situation. To address this issue, study...
Abstract Accurately controlling trace additives in dielectric barium titanate (BaTiO3) layers is important for optimizing the performance of multilayer ceramic capacitors (MLCCs). However, characterizing spatial distribution and local concentration additives, which strongly influence MLCC performance, poses a significant challenge. Atom probe tomography (APT) an ideal technique obtaining this information, but extremely low electrical conductivity piezoelectricity BaTiO3 render its analysis...
Atom probe tomography (APT) enables near atomic scale three dimensional elemental mapping through the controlled field evaporation of surface atoms triggered by combined application a DC voltage and either or laser pulses. As selected wavelength for atom probes transitioned from near-infrared (1050 nm) to shorter wavelengths e.g., green (532 ultraviolet, quality data improved range materials amenable analysis broadened. A new commercial with 257.5 nm, referred as deep ultraviolet (DUV), has...
The original version of this Article contained errors in Fig. 1b ande, which the microscopy images nanoparticles were inadvertently moved off-centre, and labels representing interplanar distances locations obtained fast Fourier transform patterns misplaced.
Proton exchange membrane fuel cells hold promise as energy conversion devices for hydrogen-based power generation and storage. However, the slow kinetics of oxygen reduction at cathode imposes need highly active catalysts, typically Pt or Pt-based, with a large available area. The scarcity increases deployment operational cost, driving development novel highly-active material systems. As an alternative, Rh-doped PtNi nanoparticle has been suggested promising catalyst, but 3D distributions...
Proton-exchange membrane fuel cells hold promise as energy conversion devices for hydrogen-based power generation and storage. However, the slow kinetics of oxygen reduction at cathode imposes need highly active catalysts, typically Pt or based, with a large available area. The scarcity increases deployment operational cost, driving development novel material systems. As an alternative, Rh-doped PtNi nanoparticle has been suggested promising catalyst, but three-dimensional distributions...
In this work, we present a novel approach for preparing atom probe tomography (APT) specimens from Pd electrocatalyst nanoparticles of less than 10 nm in size. This method is based on electrophoresis substrate followed by electroplating metallic layer. Using transmission electron microscopy (TEM) could observe that particle shape and size were well preserved after these two process steps. We routinely prepare APT the deposited nanoparticle/metal films using focused-ion- beam milling (FIB)....