Nature Communications
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2022
·Vol. 13
·期 1
·1-11
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IF 17.694
Xia Nan,Xing Jianpei,Peng Di,Ji Shiyu,Zha Jun,Yan Nan,Su Yan,Jiang Xue,Zeng Zhi,Zhao Jijun,Wu Zhikun
Nanoparticle assembly paves the way for unanticipated properties and applications from the nanoscale to the macroscopic world. However, the study of such material systems is greatly inhibited due to the obscure compositions and structures of nanoparticles (especially the surface structures). The assembly of atomically precise nanoparticles is challenging, and such an assembly of nanoparticles with metal core sizes strictly larger than 1 nm has not been achieved yet. Here, we introduced an on-site synthesis-and-assembly strategy, and successfully obtained a straight-chain assembly structure consisting of Ag 77 Cu 22 (CHT) 48 (CHT: cyclohexanethiolate) nanoparticles with two nanoparticles separated by one S atom, as revealed by mass spectrometry and single crystal X-ray crystallography. Although Ag 77 Cu 22 (CHT) 48 bears one unpaired shell-closing electron, the magnetic moment is found to be mainly localized at the S linker with magnetic isotropy, and the sulfur radicals were experimentally verified and found to be unstable after disassembly, demonstrating assembly-induced spin transfer. Besides, spin nanoparticles are found to couple and lose their paramagnetism at sufficiently short inter-nanoparticle distance, namely, the spin coupling depends on the inter-nanoparticle distance. However, it is not found that the spin coupling leads to the nanoparticle growth.
研究领域:
材料科学
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化学
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PubMed
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2019
·Vol. 34
·期 12
·2095-2104
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IF 1.982
Qianqian Dou,Yang Li,Ka Wai Wong,Ka Ming Ng
Bimetallic nanoparticles (NPs) have attracted a great deal of attention due to the synergistic interaction between metal components. In this work, the thermal process in which the reducing agent is not expensive or hazardous as those in traditional methods was employed to prepare alloy Ag–Cu NPs. The molar ratio between Ag and Cu was varied from 1:9 to 9:1. Nearly monodisperse NPs with alloy structure were characterized by X-ray diffraction and high-resolution transmission electron microscopy with energy dispersive spectroscopy In comparison with monometallic Ag and Cu NPs, the alloyed Ag–Cu NPs showed better monodispersity, especially when the ratio between Ag and Cu was 1:1. Moreover, the alloyed Ag–Cu NPs exhibited enhanced resistance to electromigration and oxidation, the respective problem of pure Ag and Cu. The alloyed Ag–Cu NPs also exhibited improved properties than a mixture of Ag–Cu NPs. This study should serve as the foundation for exploring high performance alloyed bimetallic NPs.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
·
IF 4.495
Qinghua Feng,Panpan Lin,Tiesong Lin,Peng He,Yan Liu,Weimin Long,Jian Li
A novel design of a multi-layered joint architecture, characterized by the controllable spatial distribution of ceramic reinforcements, was obtained, when brazing ZrB 2 -SiC ceramics and Ti-6Al-4 V reinforced by TiB whiskers with AgCu filler. To induce SiC reinforcements to cluster together, within the center of the filler and especially away from the ZrB 2 -SiC, SiC was added into joint, in the form of a SiC interlayer featuring a 3D-bridged network structure with continuous micro-channels infiltrated by capillary force by liquid filler during brazing. Different SiC particles were connected together, by micro-bridges being not destroyed during brazing. The layer rich in SiC could reduce thermal expansion mismatch between different substrates, the AgCu next to the ZrB 2 -SiC could relax the strain energy by high plastic deformation. Compared to joint brazed with single AgCu, joint strain energy decreased from 10.8 × 10 −6 J to 8.6 × 10 −6 J, accordingly joint shear strength increased from ∼5.4 MPa to ∼41.2 MPa.
研究领域:
材料科学
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焊接工程
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高影响因子
Science Advances
·
2026
·Vol. 12
·期 13
·
IF 13.9
Yuxiang Zhan,Kunpeng Zhao,Hexige Wuliji,Yifan Yuan,Xiang Liu,Tian-Ran Wei,Ting Zhang,Min Zhu,Xun Shi
(Ag,Cu) 2 (S,Se,Te) alloys, as rare examples of p-type inorganic ductile semiconductors, have emerged as promising candidates for wearable electronics because of their mechanical flexibility and favorable processability. However, the multicomponent nature of this system introduces diverse microstructures and intricate defect landscapes that complicate the optimization of thermoelectric performance. Here, we reveal the presence of compositionally inhomogeneous yet structurally coherent nanoscale chemical fluctuations within this alloy system. These fluctuations, together with abundant dislocations and twin boundaries, serve as efficient phonon scattering centers to suppress the lattice thermal conductivity to approach glass-like levels. Concurrently, tuning the cation ratios and vacancies allows for precise control over the carrier concentration and thereby leads to enhanced power factors. Last, a peak zT of 0.98 at 360 kelvins is achieved, marking a record for Ag-based ductile thermoelectrics. This study highlights the essential role of chemical fluctuations in modulating phonon and charge transports and offers valuable insight into the microstructure-defect–property interplay in ductile materials.
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高影响因子
TRANSITION METAL CHEMISTRY
·
2025
·
IF 1.7
Huang Na-Jing,Li Guo-Hua,Xu Long-Jun,Wang Xiao-Yi
Using a one-step co-reduction method, AgCu bimetallic nanoparticles have been successfully loaded onto few-layer boron nitride nanosheets (BNNSs), which possess high thermal conductivity. The structure and morphology of both the support and the catalyst were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). Furthermore, the influence of near-infrared laser irradiation on the catalytic performance of the catalyst was investigated. The study found that the Ag 1 Cu 1 /BNNSs nanocomposite exhibited significant catalytic activity in the reduction of 4-nitrophenol (4-NP). This nanocomposite had an activation energy of only 42.9 kJ/mol and maintained high catalytic activity even after six cycles. Additionally, it was found that near-infrared laser irradiation further enhanced the catalytic activity of the composite material. This enhancement was primarily attributed to the photothermal effect of Ag nanoparticles. Moreover, the BNNSs possess high thermal conductivity. They transferred the photothermal energy generated by the Ag nanoparticles to the external environment, thereby further enhancing the local thermal effect of the catalyst. This work provided a foundation for advancing near-infrared or solar photothermal-enhanced bimetallic nanocomposite catalytic systems.
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高影响因子
MOLECULES
·
2022
·Vol. 27
·期 20
·6951
·
IF 4.927
Yujie Tao,Fang Zhou,Kaixin Wang,Dequan Yang,Edward Sacher
Although a facile route to prepare AgCu nanoalloys (NAs) with enhanced antibacterial efficacy using Ag NP catalysis of Cu ions at elevated temperatures was previously developed, its detailed reaction process is still unclear due to the fast reaction process at higher temperatures. This work found that AgCu NAs can also be synthesized by the same process but at room temperature. AgCu NAs formation kinetics have been studied using UV–Visible spectra and Transmission Electron Microscopy (TEM), where formation includes Cu2+deposition onto the Ag NP surface and Ag+release, reduction, and agglomeration to form new Ag NPs; this is followed by a redistribution of the NA components and coalescence to form larger AgCu NPs. It is found that SPR absorption is linear with time early in the reaction, as expected for both pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetics; neither model is followed subsequently due to contributions from newly formed Ag NPs and AgCu NAs. The antibacterial efficacy of the AgCu NAs thus formed was estimated, with a continuous increase over the whole alloying process, demonstrating the correlation of antibacterial efficacy with the extent of AgCu NA formation and Ag+release.Keywords:Ag nanoparticles;AgCu nanoalloys;antibacterial efficacies;reaction kinetics
研究领域:
材料科学
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微生物学
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PubMed
高影响因子
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