Publications by authors named "L S R Kumara"

Multielement alloy nanoparticles have attracted much attention due to their attractive catalytic properties derived from the multiple interactions of adjacent multielement atoms. However, mixing multiple elements in ultrasmall nanoparticles from a wide range of elements on the periodic table is still challenging because the elements have different properties and miscibility. Herein, we developed a benchtop 4-way flow reactor for chemical synthesis of ultra-multielement alloy (UMEA) nanoparticles composed of d-block and p-block elements.

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High-entropy alloy nanoparticles (HEA NPs) emerged as catalysts with superior performances that are not shown in monometallic catalysts. Although many kinds of synthesis techniques of HEA NPs have been developed recently, synthesizing HEA NPs with ultrasmall particle size and narrow size distribution remains challenging because most of the reported synthesis methods require high temperatures that accelerate particle growth. This work provides a new methodology for the fabrication of ultrasmall and homogeneous HEA NPs using a continuous-flow reactor with a liquid-phase reduction method.

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Article Synopsis
  • - The report outlines a new total x-ray scattering (TXS) system designed for structural analysis of crystalline particle materials at the SPring-8 facility in Japan, achieving high angular resolution and a broad Q range.
  • - The system utilized five CdTe pin detectors and was controlled via LabView software to measure x-ray pair distribution functions for various materials, including Ni bulk powder and Pt/AgRh nanoparticles.
  • - Results from the TXS system included successful simulations of pair distribution functions and Rietveld refinement data that indicate long-range order in Pt nanoparticles, suggesting it could help analyze structural details, including surface characteristics, of crystalline nanoparticles.
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Transition metal carbides have attractive physical and chemical properties that are much different from their parent metals. Particularly, noble metal carbides are expected to be promising materials for a variety of applications, particularly as efficient catalysts. However, noble metal carbides have rarely been obtained because carbide phases do not appear in noble metal-carbon phase diagrams and a reasonable synthesis method to make noble metal carbides has not yet been established.

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