At elevated temperatures, bimetallic nanomaterials change their morphologies because of the interdiffusion of atomic species, which also alters their properties. The Kirkendall effect (KE) is a well-known phenomenon associated with such interdiffusion. Here, we show how KE can manifest in bimetallic nanoparticles (NPs) by following core-shell NPs of Au and Pd during heat treatment with in situ transmission electron microscopy. Unlike monometallic NPs, these core-shell NPs did not evolve into hollow core NPs. Instead, nanoscale voids formed at the bimetallic interface and then, migrated to the NP surface. Our results show that: (1) the direction of vacancy flow during interdiffusion reverses due to the higher vacancy formation energy of Pd compared to Au, and (2) nanoscale voids migrate during heating, contrary to conventional assumptions of immobile voids and void shrinkage through vacancy emission. Our results illustrate how void behavior in bimetallic NPs can differ from an idealized picture based on atomic fluxes and have important implications for the design of these materials for high-temperature applications.
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http://dx.doi.org/10.1038/s41467-019-10623-0 | DOI Listing |
Anal Chim Acta
February 2025
School of Physics and Electronic Information Engineering, Henan Polytechnic University, Jiaozuo, 454003, China. Electronic address:
Background: Trimethylamine (TMA) is a colorless, volatile gas with a strong irritating odor. Prolonged exposure to a certain amount of TMA can cause symptoms such as dizziness, nausea and difficulty breathing, and may even be life-threatening. Therefore, effective detection of TMA is crucial.
View Article and Find Full Text PDFMolecules
December 2024
School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
Hydrogenation of levulinic acid (LA) represents a significant approach for producing the high-value biomass-based platform compound γ-valerolactone (GVL). In this study, an efficient RuIr alloy bimetallic catalyst supported on SiC was synthesized and applied for the aqueous hydrogenation of LA into GVL under mild conditions. The RuIr/SiC catalyst exhibited high LA conversion and GVL selectivity (both > 99%) in water at 0.
View Article and Find Full Text PDFAnal Biochem
January 2025
Department of Studies and Research in Biochemistry, Tumkur University, Tumkur 572103, Karnataka, India. Electronic address:
Current study evaluates the beneficial role of bio-functionalized zinc ferrite nanoparticles fabricated from an aqueous extract of Decalepis hamiltonii leaves (DHLE.ZnFeO NPs) on sodium nitrite (NaNO) and Diclofenac (DFC) induced oxidative stress in RBCs and Sprague Dawley male rat models. DHLE.
View Article and Find Full Text PDFMikrochim Acta
January 2025
School of Science, Xihua University, Chengdu, 610039, People's Republic of China.
A dual-mode detection platform utilizing colorimetric and Raman was developed based on the exponential amplification reaction (EXPAR) strategy and a "core-satellite" structure constructed by bimetallic nanozymes to detect chloramphenicol (CAP). Initially, DNA-gated metal-organic frameworks (MOFs) incorporating cascaded amplification were used to be nanocarriers for the colorimetric and Raman reporter molecules (3,3',5,5'-tetramethylbiphenyl; TMB). Subsequently, assembled DNA served as gatekeepers to create a stimulus-responsive DNA-gated MOF (TMB@DNA/MOF).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Tianjin Key Laboratory of Biomedical Materials and Key Laboratory of Biomaterials and Nanotechnology for Cancer Immunotherapy, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, 300192, China.
The development of efficient therapeutic strategies to promote ferroptotic cell death offers significant potential for hepatocellular carcinoma (HCC) treatment. Herein, this study presents an HCC-targeted nanoplatform that integrates bimetallic FeMoO nanoparticles with CO-releasing molecules, and further camouflaged with SP94 peptide-modified macrophage membrane for enhanced ferroptosis-driven multi-modal therapy of HCC. Leveraging the multi-enzyme activities of the multivalent metallic elements, the nanoplatform not only decomposes HO to generate oxygen and alleviate tumor hypoxia but also depletes glutathione to inactivate glutathione peroxides 4, which amplify sonodynamic therapy and ferroptotic tumor death under ultrasound (US) irradiation.
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