共查询到20条相似文献,搜索用时 15 毫秒
1.
Shan‐Shan Wang Long Jiao Yunyang Qian Wen‐Chao Hu Gui‐Yin Xu Chen Wang Hai‐Long Jiang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10823-10827
Efficient hydrogen evolution via electrocatalytic water splitting holds great promise in modern energy devices. Herein, we demonstrate that the localized surface plasmon resonance (LSPR) excitation of Au nanorods (NRs) dramatically improves the electrocatalytic hydrogen evolution activity of CoFe‐metal–organic framework nanosheets (CoFe‐MOFNs), leading to a more than 4‐fold increase of current density at ?0.236 V (vs. RHE) for Au/CoFe‐MOFNs composite under light irradiation versus in dark. Mechanistic investigations reveal that the hydrogen evolution enhancement can be largely attributed to the injection of hot electrons from AuNRs to CoFe‐MOFNs, raising the Fermi level of CoFe‐MOFNs, facilitating the reduction of H2O and affording decreased activation energy for HER. This study highlights the superiority of plasmonic excitation on improving electrocatalytic efficiency of MOFs and provides a novel avenue towards the design of highly efficient water‐splitting systems under light irradiation. 相似文献
2.
Haixia Zhong Khoa Hoang Ly Mingchao Wang Yulia Krupskaya Xiaocang Han Jichao Zhang Jian Zhang Vladislav Kataev Bernd Büchner Inez M. Weidinger Stefan Kaskel Pan Liu Mingwei Chen Renhao Dong Xinliang Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10787-10792
Layered two‐dimensional (2D) conjugated metal–organic frameworks (MOFs) represent a family of rising electrocatalysts for the oxygen reduction reaction (ORR), due to the controllable architectures, excellent electrical conductivity, and highly exposed well‐defined molecular active sites. Herein, we report a copper phthalocyanine based 2D conjugated MOF with square‐planar cobalt bis(dihydroxy) complexes (Co‐O4) as linkages (PcCu‐O8‐Co) and layer‐stacked structures prepared via solvothermal synthesis. PcCu‐O8‐Co 2D MOF mixed with carbon nanotubes exhibits excellent electrocatalytic ORR activity (E1/2=0.83 V vs. RHE, n=3.93, and jL=5.3 mA cm?2) in alkaline media, which is the record value among the reported intrinsic MOF electrocatalysts. Supported by in situ Raman spectro‐electrochemistry and theoretical modeling as well as contrast catalytic tests, we identified the cobalt nodes as ORR active sites. Furthermore, when employed as a cathode electrocatalyst for zinc–air batteries, PcCu‐O8‐Co delivers a maximum power density of 94 mW cm?2, outperforming the state‐of‐the‐art Pt/C electrocatalysts (78.3 mW cm?2). 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(42):13181-13185
Reported herein are two new polymorphic Co‐MOFs (CTGU‐5 and ‐6) that can be selectively crystallized into the pure 2D or 3D net using an anionic or neutral surfactant, respectively. Each polymorph contains a H2O molecule, but differs dramatically in its bonding to the framework, which in turn affects the crystal structure and electrocatalytic performance for hydrogen evolution reaction (HER). Both experimental and computational studies find that 2D CTGU‐5 which has coordinates water and more open access to the cobalt site has higher electrocatalytic activity than CTGU‐6 with the lattice water. The integration with co‐catalysts, such as acetylene black (AB) leads to a composite material, AB&CTGU‐5 (1:4) with very efficient HER catalytic properties among reported MOFs. It exhibits superior HER properties including a very positive onset potential of 18 mV, low Tafel slope of 45 mV dec−1, higher exchange current density of 8.6×10−4 A cm−2, and long‐term stability. 相似文献
4.
Daopeng Sheng Lin Zhu Xing Dai Chao Xu Peng Li Carolyn I. Pearce Chengliang Xiao Jing Chen Ruhong Zhou Tao Duan Omar K. Farha Zhifang Chai Shuao Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):5022-5026
99Tc contamination at legacy nuclear sites is a serious and unsolved environmental issue. The selective remediation of 99TcO4? in the presence of a large excess of NO3? and SO42? from natural waste systems represents a significant scientific and technical challenge, since anions with a higher charge density are often preferentially sorbed by traditional anion‐exchange materials. We present a solution to this challenge based on a stable cationic metal‐organic framework, SCU‐102 (Ni2(tipm)3(NO3)4), which exhibits fast sorption kinetics, a large capacity (291 mg g?1), a high distribution coefficient, and, most importantly, a record‐high TcO4? uptake selectivity. This material can almost quantitatively remove TcO4? in the presence of a large excess of NO3? and SO42?. Decontamination experiments confirm that SCU‐102 represents the optimal Tc scavenger with the highest reported clean‐up efficiency, while first‐principle simulations reveal that the origin of the selectivity is the recognition of TcO4? by the hydrophobic pockets of the structure. 相似文献
5.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(49):15864-15868
Fabrication of hybrid MOF‐on‐MOF heteroarchitectures can create novel and multifunctional platforms to achieve desired properties. However, only MOFs with similar crystallographic parameters can be hybridized by the classical epitaxial growth method (EGM), which largely suppressed its applications. A general strategy, called internal extended growth method (IEGM), is demonstrated for the feasible assembly of MOFs with distinct crystallographic parameters in an MOF matrix. Various MOFs with diverse functions could be introduced in a modular MOF matrix to form 3D core–satellite pluralistic hybrid system. The number of different MOF crystals interspersed could be varied on demand. More importantly, the different MOF crystals distributed in individual domains could be used to further incorporate functional units or enhance target functions. 相似文献
6.
Jian Zhang Jiawei Wan Jiangyan Wang Hao Ren Ranbo Yu Lin Gu Yunling Liu Shouhua Feng Dan Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(16):5320-5325
Herein, we present heterogeneous hollow multi‐shelled structures (HoMSs) prepared by exploiting the properties of the metal–organic framework (MOFs) casing. Through accurately controlling the transformation of MOF layer into different heterogeneous casings, we can precisely design HoMSs of SnO2@Fe2O3(MOF) and SnO2@FeOx‐C(MOF), which not only retain properties of the original SnO2‐HoMSs, but also structural information from the MOFs. Tested as anode materials in LIBs, SnO2@Fe2O3 (MOF)‐HoMSs demonstrate superior lithium‐storage capacity and cycling stability to the original SnO2‐HoMSs, which can be attributed to the topological features from the MOF casing. Making a sharp contrast to the electrodes of SnO2@Fe2O3 (particle)‐HoMSs fabricated by hydrothermal method, the capacity retention after 100 cycles for the SnO2@Fe2O3 (MOF)‐HoMSs is about eight times higher than that of the SnO2@Fe2O3 (particle)‐HoMS. 相似文献
7.
Yuan Liu Xue Li Qinghua Zhang Weidong Li Yu Xie Hanyu Liu Lu Shang Zhongyi Liu Zhimin Chen Lin Gu Zhiyong Tang Tierui Zhang Siyu Lu 《Angewandte Chemie (International ed. in English)》2020,59(4):1718-1726
A challenging but pressing task to design and synthesize novel, efficient, and robust pH‐universal hydrogen evolution reaction (HER) electrocatalysts for scalable and sustainable hydrogen production through electrochemical water splitting. Herein, we report a facile method to prepare an efficient and robust Ru‐M (M=Ni, Mn, Cu) bimetal nanoparticle and carbon quantum dot hybrid (RuM/CQDs) for pH‐universal HER. The RuNi/CQDs catalysts exhibit outstanding HER performance at all pH levels. The unexpected low overpotentials of 13, 58, and 18 mV shown by RuNi/CQDs allow a current density of 10 mA cm?2 in 1 m KOH, 0.5 m H2SO4, and 1 m PBS, respectively, for Ru loading at 5.93 μgRu cm?2. This performance is among the best catalytic activities reported for any platinum‐free electrocatalyst. Theoretical studies reveal that Ni doping results in a moderate weakening of the hydrogen bonding energy of nearby surface Ru atoms, which plays a critical role in improving the HER activity. 相似文献
8.
Carolina Carrillo‐Carrin Raquel Martínez María F. NavarroPoupard Beatriz Pelaz Ester Polo Ana Arenas‐Vivo Alessandro Olgiati Pablo Taboada Mahmoud G. Soliman Úrsula Cataln Sara Fernndez‐Castillejo Rosa Sol Wolfgang J. Parak Patricia Horcajada Ramon A. Alvarez‐Puebla Pablo delPino 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7152-7156
A plasmonic core–shell gold nanostar/zeolitic‐imidazolate‐framework‐8 (ZIF‐8) nanocomposite was developed for the thermoplasmonic‐driven release of encapsulated active molecules inside living cells. The nanocomposites were loaded, as a proof of concept, with bisbenzimide molecules as functional cargo and wrapped with an amphiphilic polymer that prevents ZIF‐8 degradation and bisbenzimide leaking in aqueous media or inside living cells. The demonstrated molecule‐release mechanism relies on the use of near‐IR light coupled to the plasmonic absorption of the core gold nanostars, which creates local temperature gradients and thus, bisbenzimide thermodiffusion. Confocal microscopy and surface‐enhanced Raman spectroscopy (SERS) were used to demonstrate bisbenzimide loading/leaking and near‐IR‐triggered cargo release inside cells, thereby leading to DNA staining. 相似文献
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Neng‐Xiu Zhu Zhang‐Wen Wei Cheng‐Xia Chen Dawei Wang Chen‐Chen Cao Qian‐Feng Qiu Ji‐Jun Jiang Hai‐Ping Wang Cheng‐Yong Su 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):17189-17196
We transformed the hydrophilic metal–organic framework (MOF) UiO‐67 into hydrophobic UiO‐67‐R s (R=alkyl) by introducing alkyl chains into organic linkers, which not only protected hydrophilic Zr6O8 clusters to make the MOF interspace superoleophilic, but also led to a rough crystal surface beneficial for superhydrophobicity. The UiO‐67‐R s displayed high acid, base, and water stability, and long alkyl chains offered better hydrophobicity. Good hydrophobicity/oleophilicity were also possible with mixed‐ligand MOFs containing metal‐binding ligands. Thus, a (super)hydrophobic MOF catalyst loaded with Pd centers efficiently catalyzed Sonogashira reactions in water at ambient temperature. Studies of the hydrophobic effects of the coordination interspace and the outer surface suggest a simple de novo strategy for the synthesis of superhydrophobic MOFs that combine surface roughness and low surface energy. Such MOFs have potential for environmentally friendly catalysis and water purification. 相似文献
12.
Hang Xu Chun‐Shuai Cao Han‐Shi Hu Shi‐Bin Wang Jin‐Cheng Liu Peng Cheng Nikolas Kaltsoyannis Jun Li Bin Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(18):6083-6088
Assembled from [Th48Ni6] nanocages, the first transition‐metal (TM)‐thorium metal–organic framework (MOF, 1 ) has been synthesized and structurally characterized. 1 exhibits high solvent and acid/base stability, and resistance to 400 kGy β irradiation. Notably, 1 captures ReO4? (an analogue of radioactive 99TcO4?, a key species in nuclear wastes) with a maximum capacity of 807 mg g?1, falling among the largest values known to date. Furthermore, 1 can enrich methylene blue (MB) and can also serve as an effective and recyclable catalyst for CO2 fixation with epoxides; there is no significant loss of catalytic activity after 10 cycles. Theoretical studies with nucleus‐independent chemical shifts and natural bond orbital analysis reveal that the [Th6O8] clusters in 1 have a unique stable electronic structure with (d–p)π aromaticity, partially rationalising 1 ′s stability. 相似文献
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Beibei Li Zhanfeng Ju Mi Zhou Kongzhao Su Daqiang Yuan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7769-7773
The exploitation of new and active earth‐abundant metal catalysts is critical for sustainable chemical production. Herein, we demonstrate the design of highly efficient, robust, and reusable ZnII‐bipyridine‐based metal–organic framework (MOF) catalysts for the intramolecular hydroamination of o‐alkynylanilines to indoles. Under similar conditions homogeneous catalytic systems mainly provide hydrolysate. Our results prove that MOFs support unique internal environments that can affect the direction of chemical reactions. The ZnII‐catalyzed hydroamination reaction can be conducted without additional ligands, base, or acid, and is thus a very clean reaction system with regard to its environmental impact. 相似文献
15.
Wei Xu Hao Chen Kecheng Jie Zhenzhen Yang Tingting Li Sheng Dai 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):5072-5076
High‐entropy materials refer to a kind of materials in which five or more metal species were incorporated deliberately into a single lattice with random occupancy. Up to now, such a concept has been only restricted to hard materials, such as high‐entropy alloys and ceramics. Herein we report the synthesis of hybrid high‐entropy materials, polymetallic zeolitic imidazolate framework (also named as high‐entropy zeolitic imidazolate framework, HE‐ZIF), via entropy‐driven room‐temperature mechanochemistry. HE‐ZIF contains five metals including ZnII, CoII, CdII, NiII, and CuII which are dispersed in the ZIF structure randomly. Moreover, HE‐ZIF shows enhanced catalytic conversion of CO2 into carbonate compared with ZIF‐8 presumably a result of the synergistic effect of the five metal ions as Lewis acid in epoxide activation. 相似文献
16.
Yongqiang Zhao Tao Ling Shuangming Chen Bo Jin Anthony Vasileff Yan Jiao Li Song Jun Luo Shi‐Zhang Qiao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12380-12385
Common‐metal‐based single‐atom catalysts (SACs) are quite difficult to design due to the complex synthesis processes required. Herein, we report a single‐atom nickel iodide (SANi‐I) electrocatalyst with atomically dispersed non‐metal iodine atoms. The SANi‐I is prepared via a simple calcination step in a vacuum‐sealed ampoule and subsequent cyclic voltammetry activation. Aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy and synchrotron‐based X‐ray absorption spectroscopy are applied to confirm the atomic‐level dispersion of iodine atoms and detailed structure of SANi‐I. Single iodine atoms are found to be isolated by oxygen atoms. The SANi‐I is structural stable and shows exceptional electrocatalytic activity for the hydrogen evolution reaction (HER). In situ Raman spectroscopy reveals that the hydrogen adatom (Hads) is adsorbed by a single iodine atom, forming the I‐Hads intermediate, which promotes the HER process. 相似文献
17.
Zhiyu Lin Yang Yang Mengsi Li Hao Huang Wei Hu Ling Cheng Wensheng Yan Zhiwu Yu Kaitian Mao Guoliang Xia Jian Lu Peng Jiang Kang Yang Ruirui Zhang Pengping Xu Changlai Wang Lin Hu Qianwang Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):17129-17136
Graphene‐based materials still exhibit poor electrocatalytic activities for the hydrogen evolution reaction (HER) although they are considered to be the most promising electrocatalysts. We fabricated a graphene‐analogous material displaying exceptional activity towards the HER under acidic conditions with an overpotential (57 mV at 10 mA cm?2) and Tafel slope (44.6 mV dec?1) superior to previously reported graphene‐based materials, and even comparable to the state‐of‐the art Pt/C catalyst. X‐ray absorption near‐edge structure (XANES) and solid‐state NMR studies reveal that the distinct feature of its structure is dual graphitic‐N doping in a six‐membered carbon ring. Density functional theory (DFT) calculations show that the unique doped structure is beneficial for the activation of C?H bonds and to make the carbon atom bonded to two graphitic N atoms an active site for the HER. 相似文献
18.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(38):11584-11588
We present a crystal engineering strategy to fine tune the pore chemistry and CH4‐storage performance of a family of isomorphic MOFs based upon PCN‐14. These MOFs exhibit similar pore size, pore surface, and surface area (around 3000 m2 g−1) and were prepared with the goal to enhance CH4 working capacity. [Cu2(L2)(H2O)2]n (NJU‐Bai 41: NJU‐Bai for Nanjing University Bai's group), [Cu2(L3)(H2O)2]n (NJU‐Bai 42), and [Cu2(L4)(DMF)2]n (NJU‐Bai 43) were prepared and we observed that the CH4 volumetric working capacity and volumetric uptake values are influenced by subtle changes in structure and chemistry. In particular, the CH4 working capacity of NJU‐Bai 43 reaches 198 cm3 (STP: 273.15 K, 1 atm) cm−3 at 298 K and 65 bar, which is amongst the highest reported for MOFs under these conditions and is much higher than the corresponding value for PCN‐14 (157 cm3 (STP) cm−3). 相似文献
19.
Wei Zhou Dan‐Dan Huang Ya‐Pan Wu Jun Zhao Tao Wu Jian Zhang Dong‐Sheng Li Chenghua Sun Pingyun Feng Xianhui Bu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(13):4271-4275
The integration of heterometallic units and nanostructures into metal–organic frameworks (MOFs) used for the oxygen evolution reaction (OER) can enhance the electrocatalytic performance and help elucidate underlying mechanisms. We have synthesized a series of stable MOFs (CTGU‐10a1–d1) based on trinuclear metal carboxylate clusters and a hexadentate carboxylate ligand with a (6,6)‐connected nia net. We also present a strategy to synthesize hierarchical bimetallic MOF nanostructures (CTGU‐10a2–d2). Among these, CTGU‐10c2 is the best material for the OER, with an overpotential of 240 mV at a current density of 10 mA cm?2 and a Tafel slope of 58 mV dec?1. This is superior to RuO2 and confirms CTGU‐10c2 as one of the few known high‐performing pure‐phase MOF‐OER electrocatalysts. Notably, bimetallic CTGU‐10b2 and c2 show an improved OER activity over monometallic CTGU‐10a2 and d2. Both DFT and experiments show that the remarkable OER performance of CTGU‐10c2 is due to the presence of unsaturated metal sites, a hierarchical nanobelt architecture, and the Ni–Co coupling effect. 相似文献
20.
Yun‐Lei Peng Chaohui He Tony Pham Ting Wang Pengfei Li Rajamani Krishna Katherine A. Forrest Adam Hogan Shanelle Suepaul Brian Space Ming Fang Yao Chen Michael J. Zaworotko Jinping Li Libo Li Zhenjie Zhang Peng Cheng Banglin Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(30):10315-10320
Simultaneous removal of trace amounts of propyne and propadiene from propylene is an important but challenging industrial process. We report herein a class of microporous metal–organic frameworks ( NKMOF‐1‐M ) with exceptional water stability and remarkably high uptakes for both propyne and propadiene at low pressures. NKMOF‐1‐M separated a ternary propyne/propadiene/propylene (0.5 : 0.5 : 99.0) mixture with the highest reported selectivity for the production of polymer‐grade propylene (99.996 %) at ambient temperature, as attributed to its strong binding affinity for propyne and propadiene over propylene. Moreover, we were able to visualize propyne and propadiene molecules in the single‐crystal structure of NKMOF‐1‐M through a convenient approach under ambient conditions, which helped to precisely understand the binding sites and affinity for propyne and propadiene. These results provide important guidance on using ultramicroporous MOFs as physisorbent materials. 相似文献