Using transmission electron microscopy, we identify the temperature-dependent interaction pathway of carbon-supported Au nanoparticles. At low temperature (room temp. to 400 degrees C), Au nanoparticles predominantly interact by coalescence initiated by an atomic Au bridge. At high temperature (400-800 degrees C), the particles assemble into Au/C core-shell nanostructures. C-shells around individual nanoparticles passivate their surface and prevent coalescence. Ultimately coalescence does occur via rupture of the passivating shells, which invariably follows the assembly of C sheets enveloping and compressing multiple closely spaced Au/C nanoparticles.
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http://dx.doi.org/10.1021/nl051498b | DOI Listing |
Nanoscale Adv
October 2023
Department of Chemistry and Biochemistry, University of South Carolina Columbia South Carolina 29208 USA +1-803-777-9521 +1-803-777-2203.
Integration of plasmonic nanoantennas with catalytically active reactors in deliberately designed hybrid supra-nanostructures creates a dual-functional materials platform, based upon which precise modulation of catalytic reaction kinetics becomes accomplishable through optical excitations of plasmon resonances. Here, we have developed a multistep synthetic approach that enables us to assemble colloidal Au@C/Pt core@shell/satellite supra-nanostructures, in which the Au core functions as a light-harvesting plasmonic nanoantenna, the Pt satellites act as catalytically active reactors, and the C shell serves as a nanoscale dielectric spacer separating the reactors from the antenna, respectively. By adjusting several synthetic parameters, the size of the Au core, the thickness of the C shell, and the surface coverage of Pt satellites can all be tuned independently.
View Article and Find Full Text PDFACS Nano
September 2022
Key Laboratory of Artificial Micro/Nano Structure of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
Photons as energy carriers are clean and abundant, which can be conveniently applied for nanoactuation but the response is usually slow with very low energy efficiency/density. Here, we underpin the concept of robust nanoscale plasmonic dynamite by incorporating fullerene (C). The Au@C core-shell nanoparticles can be triggered to explode in nanoscale with synergy of plasmon-enhanced photochemical and photothermal effects.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2021
College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, Hunan University, Changsha, 410082, P. R. China.
The introduction of oxygen vacancies (Ov) has been regarded as an effective method to enhance the catalytic performance of photoanodes in oxygen evolution reaction (OER). However, their stability under highly oxidizing environment is questionable but was rarely studied. Herein, NiFe-metal-organic framework (NiFe-MOFs) was conformally coated on oxygen-vacancy-rich BiVO (Ov-BiVO ) as the protective layer and cocatalyst, forming a core-shell structure with caffeic acid as bridging agent.
View Article and Find Full Text PDFNanoscale Res Lett
January 2020
Department of Chemical Engineering, Monash University, Clayton, VIC, 3800, Australia.
This study demonstrates a simple hydrothermal method while can be generalized for controllable synthesis of noble metallic carbonaceous nanostructures (e.g., Au@C, Ag@C) under mild conditions (180-200 °C), which also provides a unique approach for fabricating hollow carbonaceous structures by removal of cores (e.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2019
Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, CAS Center for Excellence in Nanoscience , Institute of Solid State Physics, Chinese Academy of Sciences , Hefei 230031 , Anhui , PR China.
This work reports the synthesis of core-shell structured Au@C composite through a simple one-step laser ablation technique. The results demonstrate that the Au@C with a mean nanosphere size of ∼8.0 nm is composed of a spherical shaped Au core and 1-2 layered graphitic carbon shell with abundant defects.
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