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1.
Dr. Yongjin Fang Dr. Deyan Luan Dr. Ye Chen Prof. Shuyan Gao Prof. Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(7):2666-2670
The construction of hybrid architectures for electrode materials has been demonstrated as an efficient strategy to boost sodium-storage properties because of the synergetic effect of each component. However, the fabrication of hybrid nanostructures with a rational structure and desired composition for effective sodium storage is still challenging. In this study, an integrated nanostructure composed of copper-substituted CoS2@CuxS double-shelled nanoboxes (denoted as Cu-CoS2@CuxS DSNBs) was synthesized through a rational metal–organic framework (MOF)-based templating strategy. The unique shell configuration and complex composition endow the Cu-CoS2@CuxS DSNBs with enhanced electrochemical performance in terms of superior rate capability and stable cyclability. 相似文献
2.
Meng Zhao Hong‐Jie Peng Bo‐Quan Li Xiao Chen Jin Xie Xinyan Liu Qiang Zhang Jia‐Qi Huang 《Angewandte Chemie (International ed. in English)》2020,59(23):9011-9017
In situ evolution of electrocatalysts is of paramount importance in defining catalytic reactions. Catalysts for aprotic electrochemistry such as lithium–sulfur (Li‐S) batteries are the cornerstone to enhance intrinsically sluggish reaction kinetics but the true active phases are often controversial. Herein, we reveal the electrochemical phase evolution of metal‐based pre‐catalysts (Co4N) in working Li‐S batteries that renders highly active electrocatalysts (CoSx). Electrochemical cycling induces the transformation from single‐crystalline Co4N to polycrystalline CoSx that are rich in active sites. This transformation propels all‐phase polysulfide‐involving reactions. Consequently, Co4N enables stable operation of high‐rate (10 C, 16.7 mA cm?2) and electrolyte‐starved (4.7 μL mgS?1) Li‐S batteries. The general concept of electrochemically induced sulfurization is verified by thermodynamic energetics for most of low‐valence metal compounds. 相似文献
3.
Electrocatalytic Activity of a 2D Phosphorene‐Based Heteroelectrocatalyst for Photoelectrochemical Cells
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Dr. Munkhbayar Batmunkh Dr. Aabhash Shrestha Munkhjargal Bat‐Erdene Dr. Md Julker Nine Dr. Cameron J. Shearer Dr. Christopher T. Gibson Dr. Ashley D. Slattery Dr. Sherif Abdulkader Tawfik Prof. Michael J. Ford Prof. Sheng Dai Prof. Shizhang Qiao Joseph G. Shapter 《Angewandte Chemie (International ed. in English)》2018,57(10):2644-2647
Research into efficient synthesis, fundamental properties, and potential applications of phosphorene is currently the subject of intense investigation. Herein, solution‐processed phosphorene or few‐layer black phosphorus (FL‐BP) sheets are prepared using a microwave exfoliation method and used in photoelectrochemical cells. Based on experimental and theoretical (DFT) studies, the FL‐BP sheets are found to act as catalytically active sites and show excellent electrocatalytic activity for triiodide reduction in dye‐sensitized solar cells. Importantly, the device fabricated based on the newly designed cobalt sulfide (CoSx) decorated nitrogen and sulfur co‐doped carbon nanotube heteroelectrocatalyst coated with FL‐BP (FL‐BP@N,S‐doped CNTs‐CoSx) displayed an impressive photovoltaic efficiency of 8.31 %, outperforming expensive platinum based cells. This work paves the way for using phosphorene‐based electrocatalysts for next‐generation energy‐storage systems. 相似文献
4.
Yongjin Fang Bu Yuan Guan Deyan Luan Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7821-7825
Metal sulfides have received considerable attention for efficient sodium storage owing to their high capacity and decent redox reversibility. However, the poor rate capability and fast capacity decay greatly hinder their practical application in sodium‐ion batteries. Herein, an elegant multi‐step templating strategy has been developed to rationally synthesize hierarchical double‐shelled nanoboxes with the CoS2 nanosheet‐constructed outer shell supported on the CuS inner shell. Their structure and composition enable these hierarchical CuS@CoS2 nanoboxes to show boosted electrochemical properties with high capacity, outstanding rate capability, and long cycle life. 相似文献
5.
Yun‐Xiao Wang Wei‐Hong Lai Yun‐Xia Wang Shu‐Lei Chou Xinping Ai Hanxi Yang Yuliang Cao 《Angewandte Chemie (International ed. in English)》2019,58(51):18324-18337
Emerging rechargeable sodium‐ion storage systems—sodium‐ion and room‐temperature sodium–sulfur (RT‐NaS) batteries—are gaining extensive research interest as low‐cost options for large‐scale energy‐storage applications. Owing to their abundance, easy accessibility, and unique physical and chemical properties, sulfur‐based materials, in particular metal sulfides (MSx) and elemental sulfur (S), are currently regarded as promising electrode candidates for Na‐storage technologies with high capacity and excellent redox reversibility based on multielectron conversion reactions. Here, we present current understanding of Na‐storage mechanisms of the S‐based electrode materials. Recent progress and strategies for improving electronic conductivity and tolerating volume variations of the MSx anodes in Na‐ion batteries are reviewed. In addition, current advances on S cathodes in RT‐NaS batteries are presented. We outline a novel emerging concept of integrating MSx electrocatalysts into conventional carbonaceous matrices as effective polarized S hosts in RT‐NaS batteries as well. This comprehensive progress report could provide guidance for research toward the development of S‐based materials for the future Na‐storage techniques. 相似文献
6.
Minghui Zhu Pengfei Tian Ravi Kurtz Thomas Lunkenbein Jing Xu Robert Schlgl Israel E. Wachs Yi‐Fan Han 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9181-9185
The commercial high‐temperature water‐gas shift (HT‐WGS) catalyst consists of CuO‐Cr2O3‐Fe2O3, where Cu functions as a chemical promoter to increase the catalytic activity, but its promotion mechanism is poorly understood. In this work, a series of iron‐based model catalysts were investigated with in situ or pseudo in situ characterization, steady‐state WGS reaction, and density function theory (DFT) calculations. For the first time, a strong metal‐support interaction (SMSI) between Cu and FeOx was directly observed. During the WGS reaction, a thin FeOx overlayer migrates onto the metallic Cu particles, creating a hybrid surface structure with Cu‐FeOx interfaces. The synergistic interaction between Cu and FeOx not only stabilizes the Cu clusters, but also provides new catalytic active sites that facilitate CO adsorption, H2O dissociation, and WGS reaction. These new fundamental insights can potentially guide the rational design of improved iron‐based HT‐WGS catalysts. 相似文献
7.
Peng Yuan Ruihao Chen Xiaomin Zhang Fengjiao Chen Juanzhu Yan Cunfa Sun Daohui Ou Jian Peng Shuichao Lin Zichao Tang Boon K. Teo Lan‐Sun Zheng Nanfeng Zheng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(3):845-849
An effective strategy is developed to synthesize high‐nuclearity Cu clusters, [Cu53(RCOO)10(C≡CtBu)20Cl2H18]+ ( Cu53 ), which is the largest CuI/Cu0 cluster reported to date. Cu powder and Ph2SiH2 are employed as the reducing agents in the synthesis. As revealed by single‐crystal diffraction, Cu53 is arranged as a four‐concentric‐shell Cu3@Cu10Cl2@Cu20@Cu20 structure, possessing an atomic arrangement of concentric M12 icosahedral and M20 dodecahedral shells which popularly occurs in Au/Ag nanoclusters. Surprisingly, Cu53 can be dissolved in diethyl ether and spin coated to form uniform nanoclusters film on organolead halide perovskite. The cluster film can subsequently be converted into high‐quality CuI film via in situ iodination at room temperature. The as‐fabricated CuI film is an excellent hole‐transport layer for fabricating highly stable CuI‐based perovskite solar cells (PSCs) with 14.3 % of efficiency. 相似文献
8.
Coated/Sandwiched rGO/CoSx Composites Derived from Metal–Organic Frameworks/GO as Advanced Anode Materials for Lithium‐Ion Batteries
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Dr. Dongming Yin Dr. Gang Huang Dr. Feifei Zhang Dr. Yuling Qin Dr. Zhaolin Na Prof. Yaoming Wu Prof. Limin Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(4):1467-1474
Rational composite materials made from transition metal sulfides and reduced graphene oxide (rGO) are highly desirable for designing high‐performance lithium‐ion batteries (LIBs). Here, rGO‐coated or sandwiched CoSx composites are fabricated through facile thermal sulfurization of metal–organic framework/GO precursors. By scrupulously changing the proportion of Co2+ and organic ligands and the solvent of the reaction system, we can tune the forms of GO as either a coating or a supporting layer. Upon testing as anode materials for LIBs, the as‐prepared CoSx‐rGO‐CoSx and rGO@CoSx composites demonstrate brilliant electrochemical performances such as high initial specific capacities of 1248 and 1320 mA h g?1, respectively, at a current density of 100 mA g?1, and stable cycling abilities of 670 and 613 mA h g?1, respectively, after 100 charge/discharge cycles, as well as superior rate capabilities. The excellent electrical conductivity and porous structure of the CoSx/rGO composites can promote Li+ transfer and mitigate internal stress during the charge/discharge process, thus significantly improving the electrochemical performance of electrode materials. 相似文献
9.
Suppressing the P2–O2 Phase Transition of Na0.67Mn0.67Ni0.33O2 by Magnesium Substitution for Improved Sodium‐Ion Batteries
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Peng‐Fei Wang Ya You Dr. Ya‐Xia Yin Yue‐Sheng Wang Prof. Li‐Jun Wan Prof. Lin Gu Prof. Yu‐Guo Guo 《Angewandte Chemie (International ed. in English)》2016,55(26):7445-7449
Room‐temperature sodium‐ion batteries (SIBs) have shown great promise in grid‐scale energy storage, portable electronics, and electric vehicles because of the abundance of low‐cost sodium. Sodium‐based layered oxides with a P2‐type layered framework have been considered as one of the most promising cathode materials for SIBs. However, they suffer from the undesired P2–O2 phase transition, which leads to rapid capacity decay and limited reversible capacities. Herein, we show that this problem can be significantly mitigated by substituting some of the nickel ions with magnesium to obtain Na0.67Mn0.67Ni0.33?xMgxO2 (0≤x≤0.33). Both the reversible capacity and the capacity retention of the P2‐type cathode material were remarkably improved as the P2–O2 phase transition was thus suppressed during cycling. This strategy might also be applicable to the modulation of the physical and chemical properties of layered oxides and provides new insight into the rational design of high‐capacity and highly stable cathode materials for SIBs. 相似文献
10.
Yan Wang Sibo Wang Song Lin Zhang Xiong Wen Lou 《Angewandte Chemie (International ed. in English)》2020,59(29):11918-11922
Hierarchical FeCoS2–CoS2 double‐shelled nanotubes have been rationally designed and constructed for efficient photocatalytic CO2 reduction under visible light. The synthetic strategy, engaging the two‐step cation‐exchange reactions, precisely integrates two metal sulfides into a double‐shelled tubular heterostructure with both of the shells assembled from ultrathin two‐dimensional (2D) nanosheets. Benefiting from the distinctive structure and composition, the FeCoS2–CoS2 hybrid can reduce bulk‐to‐surface diffusion length of photoexcited charge carriers to facilitate their separation. Furthermore, this hybrid structure can expose abundant active sites for enhancing CO2 adsorption and surface‐dependent redox reactions, and harvest incident solar irradiation more efficiently by light scattering in the complex interior. As a result, these hierarchical FeCoS2–CoS2 double‐shelled nanotubes exhibit superior activity and high stability for photosensitized deoxygenative CO2 reduction, affording a high CO‐generating rate of 28.1 μmol h?1 (per 0.5 mg of catalyst). 相似文献
11.
Superior Na‐Storage Performance of Low‐Temperature‐Synthesized Na3(VO1−xPO4)2F1+2x (0≤x≤1) Nanoparticles for Na‐Ion Batteries
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Yuruo Qi Linqin Mu Prof. Junmei Zhao Prof. Yong‐Sheng Hu Prof. Huizhou Liu Prof. Sheng Dai 《Angewandte Chemie (International ed. in English)》2015,54(34):9911-9916
Na‐ion batteries are becoming comparable to Li‐ion batteries because of their similar chemical characteristics and abundant sources of sodium. However, the materials production should be cost‐effective in order to meet the demand for large‐scale application. Here, a series of nanosized high‐performance cathode materials, Na3(VO1?xPO4)2F1+2x (0≤x≤1), has been synthesized by a solvothermal low‐temperature (60–120 °C) strategy without the use of organic ligands or surfactants. The as‐synthesized Na3(VOPO4)2F nanoparticles show the best Na‐storage performance reported so far in terms of both high rate capability (up to 10 C rate) and long cycle stability over 1200 cycles. To the best of our knowledge, the current developed synthetic strategy for Na3(VO1?xPO4)2F1+2x is by far one of the least expensive and energy‐consuming methods, much superior to the conventional high‐temperature solid‐state method. 相似文献
12.
A Self‐Standing and Flexible Electrode of Yolk–Shell CoS2 Spheres Encapsulated with Nitrogen‐Doped Graphene for High‐Performance Lithium‐Ion Batteries
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Dr. Wenda Qiu Dr. Jiqing Jiao Dr. Jian Xia Haimin Zhong Prof. Dr. Liuping Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4359-4367
Flexible lithium‐ion batteries (LIBs) have recently attracted increasing attention with the fast development of bendable electronic systems. Herein, a facile and template‐free solvothermal method is presented for the fabrication of hybrid yolk–shell CoS2 and nitrogen‐doped graphene (NG) sheets. The yolk–shell architecture of CoS2 encapsulated with NG coating is designed for the dual protection of CoS2 to address the structural and interfacial stability concerns facing the CoS2 anode. The as‐prepared composite can be assembled into a film, which can be used as a binder‐free and flexible electrode for LIBs that does not require any carbon black conducting additives or current collectors. When evaluating lithium‐storage properties, such a flexible electrode exhibits a high specific capacity of 992 mAh g?1 in the first reversible discharge capacity at a current rate of 100 mA g?1 and high reversible capacity of 882 mAh g?1 after 150 cycles with excellent capacity retention of 89.91 %. Furthermore, a reversible capacity as high as 655 mAh g?1 is still achieved after 50 cycles even at a high rate of 5 C due to the yolk–shell structure and NG coating, which not only provide short Li‐ion and electron pathways, but also accommodate large volume variation. 相似文献
13.
Enhancing Capacity Performance by Utilizing the Redox Chemistry of the Electrolyte in a Dual‐Electrolyte Sodium‐Ion Battery
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Dr. Sirugaloor Thangavel Senthilkumar Hyuntae Bae Jinhyup Han Prof. Youngsik Kim 《Angewandte Chemie (International ed. in English)》2018,57(19):5335-5339
A strategy is described to increase charge storage in a dual electrolyte Na‐ion battery (DESIB) by combining the redox chemistry of the electrolyte with a Na+ ion de‐insertion/insertion cathode. Conventional electrolytes do not contribute to charge storage in battery systems, but redox‐active electrolytes augment this property via charge transfer reactions at the electrode–electrolyte interface. The capacity of the cathode combined with that provided by the electrolyte redox reaction thus increases overall charge storage. An aqueous sodium hexacyanoferrate (Na4Fe(CN)6) solution is employed as the redox‐active electrolyte (Na‐FC) and sodium nickel Prussian blue (Nax‐NiBP) as the Na+ ion insertion/de‐insertion cathode. The capacity of DESIB with Na‐FC electrolyte is twice that of a battery using a conventional (Na2SO4) electrolyte. The use of redox‐active electrolytes in batteries of any kind is an efficient and scalable approach to develop advanced high‐energy‐density storage systems. 相似文献
14.
In this study, we explored the feasibility of using electrochemically generated γ‐LixV2O5 as an insertion‐type anode in the lithium‐ion capacitor (LIC) with activated carbon (AC) as a cathode. Along with the native form of V2O5, their carbon composites are also used as the electrode material which is prepared by high‐energy ball milling. The electrochemical pre‐lithiation strategy is used to generate the desired γ‐phase of V2O5 (γ‐LixV2O5). Under the optimized mass loading conditions, the LICs are assembled with γ‐LixV2O5 as anode and AC as a cathode in the organic medium. Among the different LICs fabricated, AC/γ‐LixV2O5‐BM50 configuration delivered an energy density of 33.91 Wh kg?1 @ 0.22 kW kg?1 with excellent capacity retention characteristics. However, a dramatic increase in energy density (43.98 Wh kg?1@0.28 kW kg?1) is noted after the electrolyte modification with fluoroethylene carbonate. The high temperature performance of the assembled LIC is also studied and found that γ‐LixV2O5 phase can be used as a potential battery‐type component to construct high‐performance hybrid charge storage devices. 相似文献
15.
Guangbin Yang Zhanming Zhang Shengmao Zhang Laigui Yu Pingyu Zhang Yanchao Hou 《Surface and interface analysis : SIA》2013,45(11-12):1695-1701
Cu nanoparticles surface‐capped by alkanethiols were synthesized using ligand exchange method in a two‐phase system. The effects of synthetic conditions, including the pH value of CuSO4 solution, the ratio of cetyltrimethyl ammonium bromide to CuSO4, and reaction temperature, on the size and shape of as‐synthesized Cu nanoparticles were investigated. As‐synthesized Cu nanoparticles surface‐capped by alkanethiols with different chain lengths (CxS‐Cu) were characterized by means of X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectrometry, and ultraviolet–visible light spectrometry. The tribological behavior of CxS‐Cu as an additive in liquid paraffin was evaluated with a four‐ball machine. Results indicate that cetyltrimethyl ammonium bromide plays an important role in controlling the dispersion of Cu nanoparticles before adding modifier octanethiol into the reaction solution. CxS‐Cu nanoparticles as additive in liquid paraffin possess excellent antiwear and friction‐reduction performance because of the deposition of nano‐Cu with low melting point on worn steel surface leading to the formation of a self‐repairing protective layer thereon. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
Wenhui He Itamar Liberman Illya Rozenberg Raya Ifraemov Idan Hod 《Angewandte Chemie (International ed. in English)》2020,59(21):8262-8269
Metal oxides or sulfides are considered to be one of the most promising CO2 reduction reaction (CO2RR) precatalysts, owing to their electrochemical conversion in situ into highly active electrocatalytic species. However, further improvement of the performance requires new tools to gain fine control over the composition of the active species and its structural features [e.g., grain boundaries (GBs) and undercoordinated sites (USs)], directly from a predesigned template material. Herein, we describe a novel electrochemically driven cation exchange (ED‐CE) method that enables the conversion of a predesigned CoS2 template into a CO2RR catalyst, Cu2S. By means of ED‐CE, the final Cu2S catalyst inherits the original 3 D morphology of CoS2, and preserves its high density of GBs. Additionally, the catalyst's phase structure, composition, and density of USs were precisely tuned, thus enabling rational design of active CO2RR sites. The obtained Cu2S catalyst achieved a CO2‐to‐formate Faradaic efficiency of over 87 % and a record high activity (among reported Cu‐based catalysts). Hence, this study opens the way for utilization of ED‐CE reactions to design advanced electrocatalysts. 相似文献
17.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(45):14295-14300
SeS2 shows attractive advantages beyond bare S and Se as a cathode material for lithium storage. Here, a freestanding lotus root‐like carbon fiber network decorated with CoS2 nanoparticles (denoted as CoS2@LRC) has been designed and prepared as the SeS2 host for enhancing the lithium storage performance. The integrated electrode is constructed by three‐dimensional interconnected multichannel carbon fibers, which can not only accommodate high content of SeS2 (70 wt %), but also promise excellent electron and ion transport for achieving high capacity utilization of 1015 mAh g−1 at 0.2 A g−1. What is more, there are numerous CoS2 nanoparticles decorated all over the inner walls and surfaces of the carbon fibers, providing efficient sulfiphilic sites for restricting the dissolution of polysulfides and polyselenides during the electrochemical processes, thus successfully suppressing the shuttle effect and maintaining excellent cycling stability over 400 cycles at 0.5 A g−1. 相似文献
18.
One‐Pot Synthesis of CoSex–rGO Composite Powders by Spray Pyrolysis and Their Application as Anode Material for Sodium‐Ion Batteries
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Gi Dae Park Prof. Yun Chan Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(12):4140-4146
A simple one‐pot synthesis of metal selenide/reduced graphene oxide (rGO) composite powders for application as anode materials in sodium‐ion batteries was developed. The detailed mechanism of formation of the CoSex–rGO composite powders that were selected as the first target material in the spray pyrolysis process was studied. The crumple‐structured CoSex–rGO composite powders prepared by spray pyrolysis at 800 °C had a crystal structure consisting mainly of Co0.85Se with a minor phase of CoSe2. The bare CoSex powders prepared for comparison had a spherical shape and hollow structure. The discharge capacities of the CoSex–rGO composite and bare CoSex powders in the 50th cycle at a constant current density of 0.3 A g?1 were 420 and 215 mA h g?1, respectively, and their capacity retentions measured from the second cycle were 80 and 46 %, respectively. The high structural stability of the CoSex–rGO composite powders for repeated sodium‐ion charge and discharge processes resulted in superior sodium‐ion storage properties compared to those of the bare CoSex powders. 相似文献
19.
Solid‐Solution Alloy Nanoparticles of the Immiscible Iridium–Copper System with a Wide Composition Range for Enhanced Electrocatalytic Applications
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Dr. Fenglong Wang Dr. Kohei Kusada Dr. Dongshuang Wu Tomokazu Yamamoto Takaaki Toriyama Prof. Syo Matsumura Dr. Yusuke Nanba Prof. Michihisa Koyama Prof. Hiroshi Kitagawa 《Angewandte Chemie (International ed. in English)》2018,57(17):4505-4509
For the first time, we synthesize solid‐solution alloy nanoparticles of Ir and Cu with a size of ca. 2 nm, despite Ir and Cu being immiscible in the bulk up to their melting over the whole composition range. We performed a systematic characterization on the nature of the IrxCu1?x solid‐solution alloys using powder X‐ray diffraction, scanning transmission electron microscopy coupled with energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The results showed that the IrxCu1?x alloys had a face‐centered‐cubic structure; charge transfer from Cu to Ir occurred in the alloy nanoparticles, as the core‐level Ir 4f peaks shifted to lower energy region with the increase in Cu content. Furthermore, we observed that the alloying of Ir with Cu enhanced both the electrocatalytic oxygen evolution and oxygen reduction reactions. The enhanced activities could be attributed to the electronic interaction between Ir and Cu arising from the alloying effect at atomic‐level. 相似文献
20.
Eric Gottlieb Dr. Huifeng Qian Prof. Dr. Rongchao Jin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(13):4238-4243
Atomically precise alloying and de‐alloying processes for the formation of Ag–Au and Cu–Au nanoparticles of 25‐metal‐atom composition (referred to as AgxAu25?x(SR)18 and CuxAu25?x(SR)18, in which R=CH2CH2Ph) are reported. The identities of the particles were determined by matrix‐assisted laser desorption ionization mass spectroscopy (MALDI‐MS). Their structures were probed by fragmentation analysis in MALDI‐MS and comparison with the icosahedral structure of the homogold Au25(SR)18 nanoparticles (an icosahedral Au13 core protected by a shell of Au12(SR)18). The Cu and Ag atoms were found to preferentially occupy the 13‐atom icosahedral sites, instead of the exterior shell. The number of Ag atoms in AgxAu25?x(SR)18 (x=0–8) was dependent on the molar ratio of AgI/AuIII precursors in the synthesis, whereas the number of Cu atoms in CuxAu25?x(SR)18 (x=0–4) was independent of the molar ratio of CuII/AuIII precursors applied. Interestingly, the CuxAu25?x(SR)18 nanoparticles show a spontaneous de‐alloying process over time, and the initially formed CuxAu25?x(SR)18 nanoparticles were converted to pure Au25(SR)18. This de‐alloying process was not observed in the case of alloyed AgxAu25?x(SR)18 nanoparticles. This contrast can be attributed to the stability difference between CuxAu25?x(SR)18 and AgxAu25?x(SR)18 nanoparticles. These alloyed nanoparticles are promising candidates for applications such as catalysis. 相似文献