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Without using any templates or surfactants, this study develops a high-yield process to prepare vertical Ag-Pt core-shell nanowires (NWs) by thermally assisted photoreduction of Ag NWs and successive galvanic replacement between Ag and Pt ions. The clean surface of Ag nanowires allows Pt ions to reduce and deposit on it and forms a compact sheath comprising Pt nanocrystals. The core-shell structural feature of the NWs thus produced has been demonstrated via transmission electron microscopy observation and Auger electron spectroscopy elemental analysis. Kinetic analysis suggests that the deposition of Pt is an interface-controlled reaction and is dominated by the oxidative dissolution of Ag atoms. The boundaries in between Pt nanocrystals may act as microchannels for the transport of Ag ions during galvanic replacement reactions.
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http://dx.doi.org/10.1186/1556-276X-7-245 | DOI Listing |
ACS Omega
August 2025
Departamento de Engenharia Química e Engenharia de Alimentos, Universidade Federal de Santa Catarina, Campus Universitário Trindade, 88040-900 Florianópolis, SC, Brazil.
This study reports the development and application of an electrochemical sensor based on a glassy carbon electrode (GCE) modified with hollow AgAu nanoshells supported on SiO (AgAu NSs/SiO) and Nafion as a binder. The proposed AgAu NSs/SiO/NF/GCE sensor demonstrated excellent analytical performance for detecting isoproturon (ISO), a persistent environmental contaminant of significant concern. The sensor exhibited a wide linear detection range from 0.
View Article and Find Full Text PDFSci Rep
September 2025
Center for X-ray and Nano Science CXNS, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607, Hamburg, Germany.
In-situ imaging of chemical reactions can provide valuable insight into nanoparticle growth and structural evolution. Hard X-ray imaging is an excellent tool for this purpose, as it combines high spatial resolution with high penetration depth, allowing for realistic reaction environments. While far-field ptychography is a well-established method at synchrotron radiation sources, its near-field analog has received less attention.
View Article and Find Full Text PDFJ Phys Chem Lett
September 2025
Department of Applied Science and Technology (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin 10129, Italy.
The development of innovative electrocatalysts for CO reduction reaction (CORR) is essential for producing high-value chemicals and fuels. Here, we report a simple surfactant- and solvent-free strategy to fabricate Cu-Ag bimetallic gas diffusion electrodes (GDEs) via sputtering of Cu onto a carbon substrate, followed by galvanic replacement with Ag. This method yields highly pure and tunable electrodes with minimal processing steps.
View Article and Find Full Text PDFAnal Bioanal Chem
August 2025
School of Electronic Science & Engineering, Southeast University, 2 Southeast University Road, Jiangning, Nanjing, Jiangsu, 211189, P. R. China.
Flexible surface-enhanced Raman scattering (SERS) sensors show promise for non-destructive, on-site fruit quality monitoring; however, current SERS substrates frequently fail to meet the extended operational stability demands of cross-seasonal agricultural storage systems. This study presents a durable, recyclable, and stretchable plasmonic film (Au@AgNWs/PDMS) for decay detection in grapefruits. By partially embedding silver nanowires (AgNWs) in PDMS and functionalizing surfaces with gold nanoparticles via galvanic replacement, the composite film achieves high sensitivity (10⁻ M rhodamine 6G), mechanical resilience (85% tensile strain tolerance), and long-term stability (49 days).
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
August 2025
Department of Chemistry, Western Washington University, Bellingham, Washington 98225-9008, United States.
Galvanic replacement reaction (GRR) with or without a reducing agent is the most commonly used strategy to transform Ag nanocubes (AgNCs) into nanocages, and under this approach, some limited control over the nanocages' morphology and composition has been previously demonstrated. However, there is a lack of systematic study of GRR using other factors beyond a reducing agent to finely tailor the morphology and composition (mono- or bimetallic) of the nanocage formation. In addition, most previous work synthesizes AgNCs using the polyol process method, which has a number of drawbacks.
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