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1.
Rui‐Chun Luo Chao Li Xi‐Wen Du Jing Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(16):4869-4873
Monodisperse non‐noble metal nanocrystals (NCs) that are highly uniform in shapes and particle size are much desired in various advanced applications, and are commonly prepared by either thermal decomposition or reduction, where reactive organometallic precursors or/and strong reducing agents are mandatory; however, these are usually toxic, costly, or suffer a lack of availability. Bulk Group 12 metals can now be converted into ligand‐protected, highly crystalline, monodisperse spherical metal NCs with precisely controlled sizes without using any precursors and reducers. The method is based on low‐power NIR‐laser‐induced size‐selective layer‐by‐layer surface vaporization. The monodisperse Cd NCs show pronounced deep‐UV (DUV) localized surface plasmon resonance making them highly competitive DUV‐plasmonic materials. This approach will promote appreciably the emergence of a wide range of monodisperse technically important non‐coinage metal NCs with compelling functionalities. 相似文献
2.
Yulu Li Xiao Luo Tao Ding Xin Lu Kaifeng Wu 《Angewandte Chemie (International ed. in English)》2020,59(34):14292-14295
Lead halide perovskite nanocrystals (NCs) hold strong promise for a variety of light‐harvesting, emitting, and detecting applications, all of which, however, could be complicated by multicarrier Auger recombination. Therefore, complete documentation of the size‐ and composition‐dependent Auger recombination rates of these NCs is highly desirable, as it can guide system design in many applications. Herein we report the synthesis and Auger measurements of monodisperse APbX3 (A=Cs and FA; X=Cl, Br, and I) NCs in an extensive size range (ca. 3–9 nm). The biexciton Auger lifetime of all the NCs scales linearly with the NC volume. The scaling coefficient is virtually independent of the cation but rather depends sensitively on the anion, and is 0.035, 0.085, and 0.142 ps nm?3 for Cl, Br, and I, respectively. In all of these nanocrystals the Auger recombination is much faster than in standard CdSe and PbSe NCs (ca. 1 ps nm?3). 相似文献
3.
Zengchun Xie Panpan Sun Zhi Wang Hongguang Li Longyue Yu Di Sun Mengjun Chen Yuting Bi Xia Xin Jingcheng Hao 《Angewandte Chemie (International ed. in English)》2020,59(25):9922-9927
Luminescent metal nanoclusters (NCs) are emerging as a new class of functional materials that have rich physicochemical properties and wide potential applications. In recent years, it has been found that some metal NCs undergo aggregation‐induced emission (AIE) and an interesting fluorescence‐to‐phosphorescence (F‐P) switching in solutions. However, insights of both the AIE and the F‐P switching remain largely unknown. Now, gelation of water soluble, atomically precise Ag9 NCs is achieved by the addition of antisolvent. Self‐assembly of Ag9 NCs into entangled fibers was confirmed, during which AIE was observed together with an F‐P switching occurring within a narrow time scale. Structural evaluation indicates the fibers are highly ordered. The self‐assembly of Ag9 NCs and their photoluminescent property are thermally reversible, making the metal–organic gels good candidates for luminescent ratiometric thermometers. 相似文献
4.
Monodisperse AgSbS2 Nanocrystals: Size‐Control Strategy,Large‐Scale Synthesis,and Photoelectrochemistry
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Bin Zhou Mingrun Li Yihui Wu Chi Yang Prof. Wen‐Hua Zhang Prof. Can Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(31):11143-11151
We report an efficient approach to the synthesis of AgSbS2 nanocrystals (NCs) by colloidal chemistry. The size of the AgSbS2 NCs can be tuned from 5.3 to 58.3 nm with narrow size distributions by selection of appropriate precursors and fine control of the experimental conditions. Over 15 g of high‐quality AgSbS2 NCs can be obtained from one single reaction, indicative of the up‐scalability of the present synthesis. The resulting NCs display strong absorptions in the visible‐to‐NIR range and exceptional air stability. The photoelectrochemical measurements indicate that, although the pristine AgSbS2 NC electrodes generate a cathodic photocurrent with a relatively small photocurrent density and poor stability, both of them can be significantly improved subject to CdS surface modification, showing promise in solar energy conversion applications. 相似文献
5.
Ziping Wang Zhiling Zhu Chengkun Zhao Qiaofeng Yao Xiyou Li Heyuan Liu Fanglin Du Xun Yuan Jianping Xie 《化学:亚洲杂志》2019,14(6):765-769
A deep understanding on the luminescence property of aggregation‐induced emission (AIE) featured metal nanoclusters (NCs) is highly desired. This paper reports a systematic study on enhancing the luminescence of AIE‐featured Au NCs, which is achieved by Ag doping to engineer the size/structure and aggregation states of the AuI‐thiolate motifs in the NC shell. Moreover, by prolonging the reaction time, the luminescence of the as‐synthesized AuAg NCs could be further tailored from orange to red, which is also due to the variation of the AuI‐thiolate motifs of NCs. This study can facilitate a better understanding of this AIE‐featured luminescent probe and the design of other synthetic routes for this rising family of functional materials. 相似文献
6.
Graphene‐Oxide‐Modified Lanthanide Nanoprobes for Tumor‐Targeted Visible/NIR‐II Luminescence Imaging
Xiaorong Song Shihua Li Hanhan Guo Wenwu You Xiaoying Shang Renfu Li Datao Tu Wei Zheng Zhuo Chen Huanghao Yang Xueyuan Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19157-19162
The synthesis of hydrophilic lanthanide‐doped nanocrystals (Ln3+‐NCs) with molecular recognition ability for bioimaging currently remains a challenge. Herein, we present an effective strategy to circumvent this bottleneck by encapsulating Ln3+‐NCs in graphene oxide (NCs@GO). Monodisperse NCs@GO was prepared by optimizing GO size and core–shell structure of NaYF4:Yb,Er@NaYF4, thus combining the intense visible/near‐infrared II (NIR‐II) luminescence of NCs and the unique surface properties and biomedical functions of GO. Such nanostructures not only feature broad solvent dispersibility, efficient cell uptake, and excellent biocompatibility but also enable further modifications with various agents such as DNA, proteins, or nanoparticles without tedious procedures. Moreover, we demonstrate in proof‐of‐concept experiments that NCs@GO can realize simultaneous intracellular tracking and microRNA‐21 visualization, as well as highly sensitive in vivo tumor‐targeted NIR‐II imaging at 1525 nm. 相似文献
7.
Balancing the Rate of Cluster Growth and Etching for Gram‐Scale Synthesis of Thiolate‐Protected Au25 Nanoclusters with Atomic Precision
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Xun Yuan Bin Zhang Zhentao Luo Qiaofeng Yao Prof. David Tai Leong Prof. Ning Yan Prof. Jianping Xie 《Angewandte Chemie (International ed. in English)》2014,53(18):4623-4627
We report a NaOH‐mediated NaBH4 reduction method for the synthesis of mono‐, bi‐, and tri‐thiolate‐protected Au25 nanoclusters (NCs) with precise control of both the Au core and thiolate ligand surface. The key strategy is to use NaOH to tune the formation kinetics of Au NCs, i.e., reduce the reduction ability of NaBH4 and accelerate the etching ability of free thiolate ligands, leading to a well‐balanced reversible reaction for rapid formation of thermodynamically favorable Au25 NCs. This protocol is facile, rapid (≤3 h), versatile (applicable for various thiolate ligands), and highly scalable (>1 g Au NCs). In addition, bi‐ and tri‐thiolate‐protected Au25 NCs with adjustable ratios of hetero‐thiolate ligands were easily obtained. Such ligand precision in molecular ratios, spatial distribution and uniformity resulted in richly diverse surface landscapes on the Au NCs consisting of multiple functional groups such as carboxyl, amine, and hydroxy. Analysis based on NMR spectroscopy revealed that the hetero‐ligands on the NCs are well distributed with no ligand segregation. The unprecedented synthesis of multi‐thiolate‐protected Au25 NCs may further promote the practical applications of functional metal NCs. 相似文献
8.
Synthesis of Supported Ultrafine Non‐noble Subnanometer‐Scale Metal Particles Derived from Metal–Organic Frameworks as Highly Efficient Heterogeneous Catalysts
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Xinchen Kang Prof. Huizhen Liu Dr. Minqiang Hou Xiaofu Sun Hongling Han Prof. Tao Jiang Dr. Zhaofu Zhang Prof. Buxing Han 《Angewandte Chemie (International ed. in English)》2016,55(3):1080-1084
The properties of supported non‐noble metal particles with a size of less than 1 nm are unknown because their synthesis is a challenge. A strategy has now been created to immobilize ultrafine non‐noble metal particles on supports using metal–organic frameworks (MOFs) as metal precursors. Ni/SiO2 and Co/SiO2 catalysts were synthesized with an average metal particle size of 0.9 nm. The metal nanoparticles were immobilized uniformly on the support with a metal loading of about 20 wt %. Interestingly, the ultrafine non‐noble metal particles exhibited very high activity for liquid‐phase hydrogenation of benzene to cyclohexane even at 80 °C, while Ni/SiO2 with larger Ni particles fabricated by a conventional method was not active under the same conditions. 相似文献
9.
Facile Synthesis of Three‐Dimensional Pt‐TiO2 Nano‐networks: A Highly Active Catalyst for the Hydrolytic Dehydrogenation of Ammonia–Borane
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Mohammad Aref Khalily Hamit Eren Serdar Akbayrak Hepi Hari Susapto Prof. Necmi Biyikli Prof. Saim Özkar Prof. Mustafa O. Guler 《Angewandte Chemie (International ed. in English)》2016,55(40):12257-12261
Three‐dimensional (3D) porous metal and metal oxide nanostructures have received considerable interest because organization of inorganic materials into 3D nanomaterials holds extraordinary properties such as low density, high porosity, and high surface area. Supramolecular self‐assembled peptide nanostructures were exploited as an organic template for catalytic 3D Pt‐TiO2 nano‐network fabrication. A 3D peptide nanofiber aerogel was conformally coated with TiO2 by atomic layer deposition (ALD) with angstrom‐level thickness precision. The 3D peptide‐TiO2 nano‐network was further decorated with highly monodisperse Pt nanoparticles by using ozone‐assisted ALD. The 3D TiO2 nano‐network decorated with Pt nanoparticles shows superior catalytic activity in hydrolysis of ammonia–borane, generating three equivalents of H2. 相似文献
10.
Combining Electrodeposition and Optical Microscopy for Probing Size‐Dependent Single‐Nanoparticle Electrochemistry
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Dr. Jean‐François Lemineur Dr. Jean‐Marc Noël Dr. Dominique Ausserré Dr. Catherine Combellas Dr. Frédéric Kanoufi 《Angewandte Chemie (International ed. in English)》2018,57(37):11998-12002
Electrodeposition of nanoparticles (NPs) is a promising route for the preparation of highly electroactive nanostructured electrodes. By taking advantage of progressive electrodeposition, disordered arrays with a wide size distribution of Ag NPs are produced. Combined with surface‐reaction monitoring by using highly sensitive backside absorbing‐layer optical microscopy (BALM), such arrays offer a platform for screening size‐dependent electrochemistry at the single NP level. In particular, this strategy allows rationalizing the electrodeposition dynamics at the single‐NP level (>10 nm), up to the point of quantifying the presence of metal nanoclusters (<2 nm), and probing easier NP oxidation with size decrease, either through electrochemical or galvanic reactions. 相似文献
11.
Vladimir Sayevich Bin Cai Albrecht Benad Danny Haubold Luisa Sonntag Prof. Nikolai Gaponik Dr. Vladimir Lesnyak Prof. Alexander Eychmüller 《Angewandte Chemie (International ed. in English)》2016,55(21):6334-6338
We report an efficient approach to assemble a variety of electrostatically stabilized all‐inorganic semiconductor nanocrystals (NCs) by their linking with appropriate ions into multibranched gel networks. These all‐inorganic non‐ordered 3D assemblies benefit from strong interparticle coupling, which facilitates charge transport between the NCs with diverse morphologies, compositions, sizes, and functional capping ligands. Moreover, the resulting dry gels (aerogels) are highly porous monolithic structures, which preserve the quantum confinement of their building blocks. The inorganic semiconductor aerogel made of 4.5 nm CdSe colloidal NCs capped with I? ions and bridged with Cd2+ ions had a large surface area of 146 m2 g?1. 相似文献
12.
Dr. Damien Hudry Dr. Christos Apostolidis Dr. Olaf Walter Dr. Arne Janßen Dr. Dario Manara Dr. Jean‐Christophe Griveau Dr. Eric Colineau Dr. Tonya Vitova Tim Prüßmann Dr. Di Wang Dr. Christian Kübel Dr. Daniel Meyer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(33):10431-10438
Apart from its technological importance, plutonium (Pu) is also one of the most intriguing elements because of its non‐conventional physical properties and fascinating chemistry. Those fundamental aspects are particularly interesting when dealing with the challenging study of plutonium‐based nanomaterials. Here we show that ultra‐small (3.2±0.9 nm) and highly crystalline plutonium oxide (PuO2) nanocrystals (NCs) can be synthesized by the thermal decomposition of plutonyl nitrate ([PuO2(NO3)2] ? 3 H2O) in a highly coordinating organic medium. This is the first example reporting on the preparation of significant quantities (several tens of milligrams) of PuO2 NCs, in a controllable and reproducible manner. The structure and magnetic properties of PuO2 NCs have been characterized by a wide variety of techniques (powder X‐ray diffraction (PXRD), X‐ray absorption fine structure (XAFS), X‐ray absorption near edge structure (XANES), TEM, IR, Raman, UV/Vis spectroscopies, and superconducting quantum interference device (SQUID) magnetometry). The current PuO2 NCs constitute an innovative material for the study of challenging problems as diverse as the transport behavior of plutonium in the environment or size and shape effects on the physics of transuranium elements. 相似文献
13.
Noble‐metal nanocrystals (NCs) show excellent catalytic performance for many important electrocatalysis reactions. The crystallographic properties of the facets by which the NCs are bound, closely associated with the shape of the NCs, have a profound influence on the electrocatalytic function of the NCs. To develop an efficient strategy for the synthesis of NCs with controlled facets as well as compositions, understanding of the growth mechanism of the NCs and their interaction with the chemical species involved in NC synthesis is quite important. Furthermore, understanding the facet‐dependent catalytic properties of noble‐metal NCs and the corresponding mechanisms for various electrocatalysis reactions will allow for the rational design of robust electrocatalysts. In this review, we summarize recently developed synthesis strategies for the preparation of mono‐ and bimetallic noble‐metal NCs by classifying them by the type of facets through which they are enclosed and discuss the electrocatalytic applications of noble‐metal NCs with controlled facets, especially for reactions associated with fuel‐cell applications, such as the oxygen reduction reaction and fuel (methanol, ethanol, and formic acid) oxidation reactions. 相似文献
14.
Hongping Wu Bingbing Zhang Hongwei Yu Zhanggui Hu Jiyang Wang Yicheng Wu P. Shiv Halasyamani 《Angewandte Chemie (International ed. in English)》2020,59(23):8922-8926
Discovering new deep‐ultraviolet (DUV) nonlinear optical (NLO) materials is currently a great challenge. The reported DUV NLO materials are almost exclusively borates or phosphates. Silicates—the largest constituent of the earth's crust—are excluded owing to their weak second harmonic generation (SHG) response. We report a silicate, Li2BaSiO4, with edge‐sharing LiO4–SiO4 tetrahedra that achieves the balance between a short UV absorption edge, below 190 nm, and a large SHG response, 2.8×KDP. The SHG intensity is the largest for silicates without second‐order Jahn–Teller cations, and exceeds that of non‐isomorphic Li2SrSiO4 by more than an order of magnitude. As such Li2BaSiO4 may be seen as a promising DUV‐UV NLO material. This research indicates that edge‐sharing tetrahedra is a new design parameter for discovering new DUV NLO materials. 相似文献
15.
Zhennan Wu Dr. Yanchun Li Jiale Liu Prof. Zhongyuan Lu Prof. Hao Zhang Prof. Bai Yang 《Angewandte Chemie (International ed. in English)》2014,53(45):12196-12200
Metal nanoclusters (NCs) with diameter below 2 nm are promising catalysts in oxygen reduction reactions (ORR). However, the high surface energy of ultra‐small clusters leads to structural instability, shedding doubt on practical applications. Herein, we demonstrate a self‐assembly method to improve the durability of catalytic metal NCs, employing copper NCs capped by 1‐dodecanethiol (DT) to form free‐standing ribbons in colloidal solution. By tuning the cooperation between the dipolar attraction between Cu NCs and the van der Waals attraction between DT, the thickness of ribbons is adjusted to a single NC scale. Such free‐standing ribbons exhibit excellent catalytic activity and durability in ORR. 相似文献
16.
Zhennan Wu Qiaofeng Yao Osburg Jin Huang Chai Nan Ding Wen Xu Shuangquan Zang Jianping Xie 《Angewandte Chemie (International ed. in English)》2020,59(25):9934-9939
Aggregation‐induced emission (AIE) provides an efficient strategy to synthesize highly luminescent metal nanoclusters (NCs), however, rational control of emission energy and intensity of metal NCs is still challenging. This communication reveals the impact of surface AuI‐thiolate motifs on the AIE properties of Au NCs, by employing a series of water‐soluble glutathione (GSH)‐coordinated Au complexes and NCs as a model ([Au10SR10], [Au15SR13], [Au18SR14], and [Au25SR18]?, SR=thiolate ligand). Spectroscopic investigations show that the emission wavelength of Au NCs is adjustable from visible to the near‐infrared II (NIR‐II) region by controlling the length of the AuI‐SR motifs on the NC surface. Decreasing the length of AuI‐SR motifs also changes the origin of cluster luminescence from AIE‐type phosphorescence to Au0‐core‐dictated fluorescence. This effect becomes more prominent when the degree of aggregation of Au NCs increases in solution. 相似文献
17.
Silicon Nanocrystals and Silicon‐Polymer Hybrids: Synthesis,Surface Engineering,and Applications
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Dr. Mita Dasog Julian Kehrle Prof. Dr. Bernhard Rieger Prof. Dr. Jonathan G. C. Veinot 《Angewandte Chemie (International ed. in English)》2016,55(7):2322-2339
Silicon nanocrystals (Si‐NCs) are emerging as an attractive class of quantum dots owing to the natural abundance of silicon in the Earth's crust, their low toxicity compared to many Group II–VI and III–V based quantum dots, compatibility with the existing semiconductor industry infrastructure, and their unique optoelectronic properties. Despite these favorable qualities, Si‐NCs have not received the same attention as Group II–VI and III–V quantum dots, because of their lower emission quantum yields, difficulties associated with synthesizing monodisperse particles, and oxidative instability. Recent advancements indicate the surface chemistry of Si‐NCs plays a key role in determining many of their properties. This Review summarizes new reports related to engineering Si‐NC surfaces, synthesis of Si‐NC/polymer hybrids, and their applications in sensing, diodes, catalysis, and batteries. 相似文献
18.
Xiaoya Yu Linzhong Wu Di Yang Muhan Cao Xing Fan Haiping Lin Qixuan Zhong Yong Xu Qiao Zhang 《Angewandte Chemie (International ed. in English)》2020,59(34):14527-14532
Hydrochromic materials that can reversibly change color upon water treatment have attracted much attention owing to their potential applications in diverse fields. Herein, for the first time, we report that space‐confined CsPbBr3 nanocrystals (NCs) are hydrochromic. When CsPbBr3 NCs are loaded into a porous matrix, reversible transition between luminescent CsPbBr3 and non‐luminescent CsPb2Br5 can be achieved upon the exposure/removal of water. The potential applications of hydrochromic CsPbBr3 NCs in anti‐counterfeiting are demonstrated by using CsPbBr3 NCs@mesoporous silica nanospheres (around 100 nm) as the starting material. Owing to the small particle size and negatively charged surface, the as‐prepared particles can be laser‐jet printed with high precision and high speed. We demonstrate the excellent stability over repeated transformation cycles without color fade. This new discovery may not only deepen the understanding of CsPbX3, but also open a new way to design CsPbX3 materials for new applications. 相似文献
19.
A General One‐Pot Strategy for the Synthesis of High‐Performance Transparent‐Conducting‐Oxide Nanocrystal Inks for All‐Solution‐Processed Devices
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Jizhong Song Sergei A. Kulinich Jianhai Li Yanli Liu Prof. Haibo Zeng 《Angewandte Chemie (International ed. in English)》2015,54(2):462-466
For all‐solution‐processed (ASP) devices, transparent conducting oxide (TCO) nanocrystal (NC) inks are anticipated as the next‐generation electrodes to replace both those synthesized by sputtering techniques and those consisting of rare metals, but a universal and one‐pot method to prepare these inks is still lacking. A universal one‐pot strategy is now described; through simply heating a mixture of metal–organic precursors a wide range of TCO NC inks, which can be assembled into high‐performance electrodes for use in ASP optoelectronics, were synthesized. This method can be used for various oxide NC inks with yields as high as 10 g. The formed NCs are of high crystallinity, uniform morphology, monodispersity, and high ink stability and feature effective doping. Therefore, the inks can be readily assembled into films with a surface roughness of 1.6 nm. Typically, a sheet resistance of 110 Ω sq?1 can be achieved with a transmittance of 88 %, which is the best performance for TCO NC ink‐based electrodes described to date. These electrodes can thus drive a polymer light‐emitting diode (PLED) with a luminance of 2200 cd m?2 at 100 mA cm?2. 相似文献
20.
Cecilia Cerretani Hiroki Kanazawa Tom Vosch Jiro Kondo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17313-17317
DNA has been used as a scaffold to stabilize small, atomically monodisperse silver nanoclusters, which have attracted attention due to their intriguing photophysical properties. Herein, we describe the X‐ray crystal structure of a DNA‐encapsulated, near‐infrared emitting Ag16 nanocluster (DNA–Ag16NC). The asymmetric unit of the crystal contains two DNA–Ag16NCs and the crystal packing between the DNA–Ag16NCs is promoted by several interactions, such as two silver‐mediated base pairs between 3′‐terminal adenines, two phosphate–Ca2+–phosphate interactions, and π‐stacking between two neighboring thymines. Each Ag16NC is confined by two DNA decamers that take on a horse‐shoe‐like conformation and is almost fully shielded from the solvent environment. This structural insight will aid in the determination of the structure/photophysical property relationship for this class of emitters and opens up new research opportunities in fluorescence imaging and sensing using noble‐metal clusters. 相似文献