排序方式: 共有16条查询结果,搜索用时 109 毫秒
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Hao Zhang Wei Xia Haoming Shen Wenhan Guo Zibin Liang Kexin Zhang Yingxiao Wu Bingjun Zhu Ruqiang Zou 《Angewandte Chemie (International ed. in English)》2020,59(5):1871-1877
Antiperovskite Co3InC0.7N0.3 nanomaterials with highly enhanced oxygen reduction reaction (ORR) performance were prepared by tuning nitrogen contents through a metal–organic framework (MOF)‐derived strategy. The nanomaterial surpasses all reported noble‐metal‐free antiperovskites and even most perovskites in terms of onset potential (0.957 V at J=0.1 mA cm?2) and half‐wave potential (0.854 V). The OER and zinc–air battery performance demonstrate its multifunctional oxygen catalytic activities. DFT calculation was performed and for the first time, a 4 e? dissociative ORR pathway on (200) facets of antiperovskite was revealed. Free energy studies showed that nitrogen substitution could strengthen the OH desorption as well as hydrogenation that accounts for the enhanced ORR performance. This work expands the scope for material design via tailoring the nitrogen contents for optimal reaction free energy and hence performance of the antiperovskite system. 相似文献
2.
Suppressed formation of CO2 and H2O in the oxidative coupling of methane over La2O3/MgO catalyst by surface modification 下载免费PDF全文
Oxidative coupling of methane (OCM) is a promising way to convert methane into C_2 hydrocarbons. However, CO_2 and H_2O are by-products of the reaction. To utilize the higher activity of lanthanum oxide and save its usage, MgO supported La_2O_3 catalyst was prepared. Surface modification of the catalyst with nitric acid was made to suppress the formation of the by-products. Experimental results indicated that the addition of nitric acid increased the surface oxygen species with binding energy of ca. 531.7 eV and at the same time reduced the pore volume of the catalyst. These effects of nitric acid finally led to the increase of C_2 selectivity and the decrease of the by-products formation. Hydrogen selectivity was found about 14%- 18% over the catalysts adopted in this work. 相似文献
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Linearly Tunable Emission Colors Obtained from a Fluorescent–Phosphorescent Dual‐Emission Compound by Mechanical Stimuli 下载免费PDF全文
Dr. Zhu Mao Dr. Zhiyong Yang Dr. Yingxiao Mu Prof. Yi Zhang Dr. Yi‐Fan Wang Prof. Zhenguo Chi Dr. Chang‐Cheng Lo Prof. Siwei Liu Dr. Alan Lien Prof. Jiarui Xu 《Angewandte Chemie (International ed. in English)》2015,54(21):6270-6273
Organic mechanoluminochromic materials are mechano/piezo‐responsive and promising for applications in sensors, displays, and data storage devices. However, their switching range of emission is seriously impeded by only one kind of emission (either a fluorescent or phosphorescent peak) in the spectrum of single organic compounds. This study presents a design strategy for pure organic compounds with excellent room‐temperature fluorescent–phosphorescent dual‐emission (rFPDE) properties, which combines the effective factors of dipenylsulfone group, crystalline state, and heavy atom effect. Following the principle of color mixing, myriad emission colors with a wide range from orange to purple and across white zone in a straight line in the chromaticity diagram of the Commission Internationale de l’Eclairage (CIE) can be obtained by simply mechanical grinding the compound. The unique properties could be concentrated on a pure organic compound through this design strategy, which provides a new efficient channel for the discovery of efficient mechano‐responsive organic materials. 相似文献
5.
Nickel(II) complex containing N‐(4,5‐dihydrooxazol‐2‐yl)benzamide ligands: highly efficient catalyst for Heck coupling reactions 下载免费PDF全文
Heck reaction catalyzed by Ni(II) containing N‐(4,5‐dihydrooxazol‐2‐yl) benzamide has been developed. The coupling of alkenes with aryl iodide or aryl bromide in the presence of potassium carbonate in DMF provides the corresponding products with moderate to good yields. This method possesses obvious advantages such as low‐cost catalyst and simple experimental operation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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An Organic Molecule with Asymmetric Structure Exhibiting Aggregation‐Induced Emission,Delayed Fluorescence,and Mechanoluminescence 下载免费PDF全文
Shidang Xu Dr. Tingting Liu Dr. Yingxiao Mu Dr. Yi‐Fan Wang Prof. Zhenguo Chi Dr. Chang‐Cheng Lo Prof. Siwei Liu Prof. Yi Zhang Dr. Alan Lien Prof. Jiarui Xu 《Angewandte Chemie (International ed. in English)》2015,54(3):874-878
Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light‐emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation‐induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE‐active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3 %, which is the highest quantum yield, to the best of our knowledge, for long‐lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound. 相似文献
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Dr. Ruo Zhao Dr. Song Gao Yingxiao Wu Zibin Liang Dr. Hao Zhang Dr. Wei Xia Dr. Shuai Li Prof. Yusheng Zhao Prof. Ruqiang Zou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(18):4001-4006
Transition-metal-based phosphides (TMPs) have been considered as attractive electrocatalysts for water splitting due to their earth-abundance and remarkable catalytic activity. As a representative type of precursors, metal-organic frameworks (MOFs) provide ideal plateaus for the design of nanostructured TMPs. In this work, the hierarchically structured iron phosphide nanobundles (FeP-500) were fabricated by one-step phosphorization of an iron-based MOF (MET(Fe)) precursor. The derived FeP-500 nanobundles were constructed by quasi-paralleled one-dimensional nanorods with uneven surface, which provided channels for electrolyte penetration, mass transport, and effective exposure of active sites during the water-splitting process. With the addition of conductive Super P, the obtained FeP-500-S exhibited a good electrocatalytic performance towards the hydrogen evolution reaction in alkaline electrolyte (1 mol L−1 KOH). Furthermore, to investigate the influence of secondary metal doping, a series of isoreticular MOF precursors and bimetallic TMPs were fabricated. The results indicated that the catalytic performance is structure dominated. 相似文献
8.
Shidang Xu Tingting Liu Yingxiao Mu Yi‐Fan Wang Zhenguo Chi Chang‐Cheng Lo Siwei Liu Yi Zhang Alan Lien Jiarui Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(3):888-892
Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light‐emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation‐induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE‐active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3 %, which is the highest quantum yield, to the best of our knowledge, for long‐lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound. 相似文献
9.
Wu Luyan Zeng Wenhui Feng Liandong Hu Yuxuan Sun Yidan Yan Yingxiao Chen Hong-Yuan Ye Deju 《中国科学:化学(英文版)》2020,63(5):741-750
Ratiometric fluorescent probes hold great promise for in vivo imaging; however, stimuli-activatable ratiometric probes with fluorescence emissions in near-infrared(NIR) region are still very few. Herein, we report a hydrogen sulfide(H_2S)-activatable ratiometric NIR fluorescent probe(1-SPN) by integrating a H_2S-responsive NIR fluorescent probe 1 into a H_2S-inert poly[2,6-(4,4-bis-(2-ethylhexyl)-4 H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)](PCPDTBT)-based NIR semiconducting polymer nanoparticle(SPN). 1-SPN shows "always on" PCPDTBT fluorescence at 830 nm and weak probe 1 fluorescence at 725 nm under excitation at 680 nm. The ratio of NIR fluorescence intensities between 725 and 830 nm(I_(725)/I_(830))is small. Upon interaction with H_2S, the fluorescence at 725 nm is rapidly switched on, resulting in a large enhancement of I_(725)/I_(830), which is allowed for sensitive visualization and quantification of H_2S concentrations in living cells. Taking advantage of enhanced tissue penetration depth of NIR fluorescence, 1-SPN is also applied for real-time ratiometric fluorescence imaging of hepatic and tumor H_2S in living mice. This study demonstrates that activatable ratiometric NIR fluorescent probes hold great potential for in vivo imaging. 相似文献
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Intermolecular Electronic Coupling of Organic Units for Efficient Persistent Room‐Temperature Phosphorescence 下载免费PDF全文
Dr. Zhiyong Yang Dr. Zhu Mao Dr. Xuepeng Zhang Dr. Depei Ou Dr. Yingxiao Mu Prof. Yi Zhang Prof. Cunyuan Zhao Prof. Siwei Liu Prof. Zhenguo Chi Prof. Jiarui Xu Dr. Yuan‐Chun Wu Dr. Po‐Yen Lu Dr. Alan Lien Prof. Martin R. Bryce 《Angewandte Chemie (International ed. in English)》2016,55(6):2181-2185
Although persistent room‐temperature phosphorescence (RTP) emission has been observed for a few pure crystalline organic molecules, there is no consistent mechanism and no universal design strategy for organic persistent RTP (pRTP) materials. A new mechanism for pRTP is presented, based on combining the advantages of different excited‐state configurations in coupled intermolecular units, which may be applicable to a wide range of organic molecules. By following this mechanism, we have developed a successful design strategy to obtain bright pRTP by utilizing a heavy halogen atom to further increase the intersystem crossing rate of the coupled units. RTP with a remarkably long lifetime of 0.28 s and a very high quantum efficiency of 5 % was thus obtained under ambient conditions. This strategy represents an important step in the understanding of organic pRTP emission. 相似文献