共查询到20条相似文献,搜索用时 15 毫秒
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Miaomiao Ye Qiao Zhang Yongxing Hu Jianping Ge Dr. Zhenda Lu Le He Zhonglin Chen Prof. Yadong Yin Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(21):6243-6250
Core–shell structured Fe3O4/SiO2/TiO2 nanocomposites with enhanced photocatalytic activity that are capable of fast magnetic separation have been successfully synthesized by combining two steps of a sol–gel process with calcination. The as‐obtained core–shell structure is composed of a central magnetite core with a strong response to external fields, an interlayer of SiO2, and an outer layer of TiO2 nanocrystals with a tunable average size. The convenient control over the size and crystallinity of the TiO2 nanocatalysts makes it possible to achieve higher photocatalytic efficiency than that of commercial photocatalyst Degussa P25. The photocatalytic activity increases as the thickness of the TiO2 nanocrystal shell decreases. The presence of SiO2 interlayer helps to enhance the photocatalytic efficiency of the TiO2 nanocrystal shell as well as the chemical and thermal stability of Fe3O4 core. In addition, the TiO2 nanocrystals strongly adhere to the magnetic supports through covalent bonds. We demonstrate that this photocatalyst can be easily recycled by applying an external magnetic field while maintaining their photocatalytic activity during at least eighteen cycles of use. 相似文献
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Oxide‐Supported IrNiOx Core–Shell Particles as Efficient,Cost‐Effective,and Stable Catalysts for Electrochemical Water Splitting 下载免费PDF全文
Hong Nhan Nong Dr. Hyung‐Suk Oh Tobias Reier Dr. Elena Willinger Dr. Marc‐Georg Willinger Prof. Dr. Valeri Petkov Dr. Detre Teschner Prof. Dr. Peter Strasser 《Angewandte Chemie (International ed. in English)》2015,54(10):2975-2979
Active and highly stable oxide‐supported IrNiOx core–shell catalysts for electrochemical water splitting are presented. IrNix@IrOx nanoparticles supported on high‐surface‐area mesoporous antimony‐doped tin oxide (IrNiOx /Meso‐ATO) were synthesized from bimetallic IrNix precursor alloys (PA‐IrNix /Meso‐ATO) using electrochemical Ni leaching and concomitant Ir oxidation. Special emphasis was placed on Ni/NiO surface segregation under thermal treatment of the PA‐IrNix /Meso‐ATO as well as on the surface chemical state of the particle/oxide support interface. Combining a wide array of characterization methods, we uncovered the detrimental effect of segregated NiO phases on the water splitting activity of core–shell particles. The core–shell IrNiOx /Meso‐ATO catalyst displayed high water‐splitting activity and unprecedented stability in acidic electrolyte providing substantial progress in the development of PEM electrolyzer anode catalysts with drastically reduced Ir loading and significantly enhanced durability. 相似文献
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Benjamin P. Williams Allison P. Young Ilektra Andoni Yong Han Wei‐Shang Lo Matthew Golden Jane Yang Lian‐Ming Lyu Chun‐Hong Kuo James W. Evans Wenyu Huang Chia‐Kuang Tsung 《Angewandte Chemie (International ed. in English)》2020,59(26):10574-10580
Controlling the surface composition of shaped bimetallic nanoparticles could offer precise tunability of geometric and electronic surface structure for new nanocatalysts. To achieve this goal, a platform for studying the intermixing process in a shaped nanoparticle was designed, using multilayered Pd‐Ni‐Pt core–shell nanocubes as precursors. Under mild conditions, the intermixing between Ni and Pt could be tuned by changing layer thickness and number, triggering intermixing while preserving nanoparticle shape. Intermixing of the two metals is monitored using transmission electron microscopy. The surface structure evolution is characterized using electrochemical methanol oxidation. DFT calculations suggest that the low‐temperature mixing is enhanced by shorter diffusion lengths and strain introduced by the layered structure. The platform and insights presented are an advance toward the realization of shape‐controlled multimetallic nanoparticles tailored to each potential application. 相似文献
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Haiyan Liu Dr. Tingting Wang Lingyu Zhang Lu Li Dr. Y. Andrew Wang Prof. Dr. Chungang Wang Prof. Dr. Zhongmin Su 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3745-3752
The selected‐control preparation of uniform core–shell and yolk–shell architectures, which combine the multiple functions of a superparamagnetic iron oxide (SPIO) core and europium‐doped yttrium oxide (Y2O3:Eu) shell in a single material with tunable fluorescence and magnetic properties, has been successfully achieved by controlling the heat‐treatment conditions. Furthermore, the shell thickness and interior cavity of SPIO@Y2O3:Eu core–shell and yolk–shell nanostructures can be precisely tuned. Importantly, as‐prepared SPIO@Y2O3:Eu yolk–shell nanocapsules (NCs) modified with amino groups as cancer‐cell fluorescence imaging agents are also demonstrated. To the best of our knowledge, this is the first report on the selected‐control fabrication of uniform SPIO@Y2O3:Eu core–shell nanoparticles and yolk–shell NCs. The combined magnetic manipulation and optical monitoring of magnetic–fluorescent SPIO@Y2O3:Eu yolk–shell NCs will open up many exciting opportunities in dual imaging for targeted delivery and thermal therapy. 相似文献
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Kasibhatta Josena Datta Dr. Kasibhatta Kumara Ramanatha Datta Dr. Manoj B. Gawande Dr. Vaclav Ranc Dr. Klára Čépe Dr. Victor Malgras Prof. Yusuke Yamauchi Prof. Rajender S. Varma Prof. Dr. Radek Zboril 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1577-1581
A facile synthesis based on the addition of ascorbic acid to a mixture of Na2PdCl4, K2PtCl6, and Pluronic P123 results in highly branched core–shell nanoparticles (NPs) with a micro–mesoporous dandelion‐like morphology comprising Pd core and Pt shell. The slow reduction kinetics associated with the use of ascorbic acid as a weak reductant and suitable Pd/Pt atomic ratio (1:1) play a principal role in the formation mechanism of such branched Pd@Pt core–shell NPs, which differs from the traditional seed‐mediated growth. The catalyst efficiently achieves the reduction of a variety of olefins in good to excellent yields. Importantly, higher catalytic efficiency of dandelion‐like Pd@Pt core–shell NPs was observed for the olefin reduction than commercially available Pt black, Pd NPs, and physically admixed Pt black and Pd NPs. This superior catalytic behavior is not only due to larger surface area and synergistic effects but also to the unique micro–mesoporous structure with significant contribution of mesopores with sizes of several tens of nanometers. 相似文献
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Lucy R. Holt Dr. Blake J. Plowman Dr. Neil P. Young Dr. Kristina Tschulik Prof. Richard G. Compton 《Angewandte Chemie (International ed. in English)》2016,55(1):397-400
We report the direct solution‐phase characterization of individual gold‐core silver‐shell nanoparticles through an electrochemical means, with selectivity achieved between the core and shell components based on their different redox activities. The electrochemically determined core–shell sizes are in excellent agreement with electron microscopy‐based results, successfully demonstrating the electrochemical characterization of individual core–shell nanoparticles. 相似文献
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One‐Step Synthesis of Metal@Titania Core–Shell Materials for Visible‐Light Photocatalysis and Catalytic Reduction Reaction 下载免费PDF全文
Dr. Zhigang Xiong Luhong Zhang Prof. Xiu Song Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14715-14720
Metal@TiO2 composites with a core–shell structure possess multifunctional properties. The demonstrated protocols for synthesizing such materials involve multiple steps, requiring precise control over the particle uniformity of the core and shell thickness, as well as complex surface modification. A simple approach to synthesizing metal@TiO2 hybrid nanostructures remains a great challenge. Herein, we report on a one‐step method for the preparation of metal@TiO2 core–shell nanospheres, which exhibited excellent performance in photocatalytic degradation of recalcitrant organic pollutants under visible light irradiation, and in catalytic reduction of nitrophenol in water. The simple method described here represents a sustainable approach to preparing core–shell materials at low cost, involving fewer chemicals, and requiring less energy, which will make a significant contribution toward large‐scale synthesis of high‐performance hybrid materials for photocatalytic applications. 相似文献
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Dr. Kaiguang Yang Dr. Zhen Liang Prof. Dr. Lihua Zhang Prof. Yukui Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):9056-9062
The boronic acid‐functionalized core–shell polymer nanoparticles, poly(N,N‐methylenebisacrylamide‐co‐methacrylic acid)@4‐vinylphenylboronic acid (poly(MBA‐co‐MAA)@VPBA), were successfully synthesized for enriching glycosylated peptides. Such nanoparticles were composed of a hydrophilic polymer core prepared by distillation precipitation polymerization (DPP) and a boronic acid‐functionalized shell designed for capturing glycopeptides. Owing to the relatively large amount of residual vinyl groups introduced by DPP on the core surface, the VPBA monomer was coated with high efficiency, working as the shell. Moreover, the overall polymerization route, especially the use of DPP, made the synthesis of nanoparticles facile and time‐saving. With the poly(MBA‐co‐MAA)@VPBA nanoparticles, 18 glycopeptides from horseradish peroxidase (HRP) digest were captured and identified by MALDI‐TOF mass spectrometric analysis, relative to eight glycopeptides enriched by using commercially available meta‐aminophenylboronic acid agarose under the same conditions. When the concentration of the HRP digest was decreased to as low as 5 nmol, glycopeptides could still be selectively isolated by the prepared nanoparticles. Our results demonstrated that the synthetic poly(MBA‐co‐MAA)@VPBA nanoparticles might be a promising selective enrichment material for glycoproteome analysis. 相似文献
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Karl J. J. Mayrhofer Dr. Viktorija Juhart Katrin Hartl Marianne Hanzlik Dr. Matthias Arenz Dr. 《Angewandte Chemie (International ed. in English)》2009,48(19):3529-3531
Coming to the surface : The surface composition of carbon‐supported Pt3Co catalyst particles changes upon a CO‐annealing treatment. Platinum atoms segregate to the particle surface so that nanoparticles with a platinum shell surrounding an alloy core are formed. This modified catalyst has a superior activity in the oxygen reduction reaction compared to both a plain platinum catalyst and the untreated alloy particles.
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Dr. Xiao‐Yu Li Dr. Yuan‐Zhi Tan Dr. Kai Yu Xing‐Po Wang Ya‐Qin Zhao Dr. Di Sun Lan‐Sun Zheng 《化学:亚洲杂志》2015,10(6):1295-1298
Atomically precise polyoxometalate–Ag2S core–shell nanoparticles were generated in a top‐down approach under solvothermal conditions and structurally confirmed by X‐ray single‐crystal diffraction as an interesting core–shell structure comprising an in situ generated Mo6O228? polyoxometalate core and a mango‐like Ag58S38 shell. This result demonstrates the possibility to integrate polyoxometalate and Ag2S nanoparticles into a core–shell heteronanostructure with precisely controlled atomical compositions of both core and shell. 相似文献
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Xingmiao Zhang Haichen Liang Haoze Li Yuan Xia Xiaohang Zhu Liang Peng Wei Zhang Liangliang Liu Tiancong Zhao Changyao Wang Zaiwang Zhao Chin‐Te Hung Moustafa M. Zagho Ahmed A. Elzatahry Wei Li Dongyuan Zhao 《Angewandte Chemie (International ed. in English)》2020,59(8):3287-3293
A universal sequential synthesis strategy in aqueous solution is presented for highly uniform core–shell structured photocatalysts, which consist of a metal sulfide light absorber core and a metal sulfide co‐catalyst shell. We show that the sequential chemistry can drive the formation of unique core–shell structures controlled by the constant of solubility product of metal sulfides. A variety of metal sulfide core–shell structures have been demonstrated, including CdS@CoSx, CdS@MnSx, CdS@NiSx, CdS@ZnSx, CuS@CdS, and more complexed CdS@ZnSx@CoSx. The obtained strawberry‐like CdS@CoSx core–shell structures exhibit a high photocatalytic H2 production activity of 3.92 mmol h?1 and an impressive apparent quantum efficiency of 67.3 % at 420 nm, which is much better than that of pure CdS nanoballs (0.28 mmol h?1), CdS/CoSx composites (0.57 mmol h?1), and 5 %wt Pt‐loaded CdS photocatalysts (1.84 mmol h?1). 相似文献
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Dual‐Pore Mesoporous Carbon@Silica Composite Core–Shell Nanospheres for Multidrug Delivery 下载免费PDF全文
Yin Fang Prof. Gengfeng Zheng Jianping Yang Haosha Tang Yafeng Zhang Biao Kong Yingying Lv Prof. Congjian Xu Prof. Abdullah M. Asiri Prof. Jian Zi Prof. Fan Zhang Prof. Dongyuan Zhao 《Angewandte Chemie (International ed. in English)》2014,53(21):5366-5370
Monodispersed mesoporous phenolic polymer nanospheres with uniform diameters were prepared and used as the core for the further growth of core–shell mesoporous nanorattles. The hierarchical mesoporous nanospheres have a uniform diameter of 200 nm and dual‐ordered mesopores of 3.1 and 5.8 nm. The hierarchical mesostructure and amphiphilicity of the hydrophobic carbon cores and hydrophilic silica shells lead to distinct benefits in multidrug combination therapy with cisplatin and paclitaxel for the treatment of human ovarian cancer, even drug‐resistant strains. 相似文献
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Dr. Shan Jiang Dr. Yi Du Dr. Marco Marcello Dr. Edward W. Corcoran Jr. Dr. David C. Calabro Dr. Samantha Y. Chong Dr. Linjiang Chen Rob Clowes Dr. Tom Hasell Prof. Andrew I. Cooper 《Angewandte Chemie (International ed. in English)》2018,57(35):11228-11232
The first examples of core–shell porous molecular crystals are described. The physical properties of the core–shell crystals, such as surface hydrophobicity, CO2 /CH4 selectivity, are controlled by the chemical composition of the shell. This shows that porous core–shell molecular crystals can exhibit synergistic properties that out‐perform materials built from the individual, constituent molecules. 相似文献
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Facile Preparation of Core–Shell Magnetic Metal–Organic Framework Nanospheres for the Selective Enrichment of Endogenous Peptides 下载免费PDF全文
Dr. Zhichao Xiong Dr. Yongsheng Ji Chunli Fang Quanqing Zhang Prof. Lingyi Zhang Prof. Mingliang Ye Prof. Weibing Zhang Prof. Hanfa Zou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(24):7389-7395
Facile preparation of core–shell magnetic metal–organic framework nanospheres by a layer‐by‐layer approach is presented. The nanospheres have high surface area (285.89 cm2 g?1), large pore volume (0.18 cm3 g?1), two kinds of mesopores (2.50 and 4.72 nm), excellent magnetic responsivity (55.65 emu g?1), structural stability, and good dispersibility. The combination of porosity, hydrophobicity, and uniform magnetism was exploited for effective enrichment of peptides with simultaneous exclusion of high molecular weight proteins. The nanospheres were successfully applied in the selective enrichment of endogenous peptides in human serum. 相似文献