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metal-organic framework

Avelino Corma, Pilar García-García, Sergio Rojas-Buzo
A series of highly crystalline, porous, hafnium-based metal-organic frameworks (MOFs) have shown to catalyze the transfer hydrogenation reaction of levulinic ester to produce γ-valerolactone using isopropanol as hydrogen donor and the results are compared with the zirconium-based counterparts. The role of the metal center in Hf-MOFs has been identified and reaction parameters optimized. NMR studies with isotopically labeled isopropanol evidences that the transfer hydrogenation occurs via a direct intermolecular hydrogen transfer route...
November 15, 2017: ChemSusChem
Ghasem Sargazi, Daryoush Afzali, Ali Mostafavi
Reverse micelle (RM) and ultrasound assisted reverse micelle (UARM) were applied to the synthesis of novel thorium nanostructures as metal organic frameworks (MOFs). Characterization with different techniques showed that the Th-MOF sample synthesized by UARM method had higher thermal stability (354°C), smaller mean particle size (27nm), and larger surface area (2.02×10(3)m(2)/g). Besides, in this novel approach, the nucleation of crystals was found to carry out in a shorter time. The synthesis parameters of UARM method were designed by 2(k-1) factorial and the process control was systematically studied using analysis of variance (ANOVA) and response surface methodology (RSM)...
March 2018: Ultrasonics Sonochemistry
Mahboobeh Tanhaei, Ali Reza Mahjoub, Vahid Safarifard
Graphene oxide-[Zn2(oba)2(bpfb)]·(DMF)5 metal-organic framework nanocomposite (GO-TMU-23; H2oba=4,4'-oxybisbenzoic acid, bpfb=N,N'-bis-(4-pyridylformamide)-1,4-benzenediamine, DMF=N,N-dimethylformamide) is prepared through a simple and large-scale sonochemical preparation method at room temperature. The obtained nanocomposite is characterized by Field Emission Scanning Electron Microscopy (FE-SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Additionally, the absorption ability of GO-TMU-23 nanocomposite toward cationic dye methylene blue was also performed...
March 2018: Ultrasonics Sonochemistry
Sayed Ali Akbar Razavi, Mohammad Yaser Masoomi, Ali Morsali
A pillared MOF, [Zn(OBA)(H2DPT)0.5].DMF (TMU-34), based on dihydro tetrazine functionalized pillar spacer (H2DPT=3,6-di(pyridin-4-yl)-1,4-dihydro-1,2,4,5-tetrazine) and V-shape dicarboxylate linker (H2OBA=4,4'-oxybis(benzoic acid)) was synthesized by reflux and ultrasonic methods. The effects of sonication time, initial concentration of reagents and sonication power on size and morphology have been optimized. This MOF has been characterized by scanning electron microscopy, FT-IR spectra, X-ray powder diffraction and N2 adsorption at 77K...
March 2018: Ultrasonics Sonochemistry
Shiqiang Cui, Shuqing Gu, Yaping Ding, Jiangjiang Zhang, Zhen Zhang, Zongqian Hu
Hollow mesoporous CuCo2O4 (meso-CuCo2O4) microspheres were successfully synthesized by decomposing metal-organic frameworks (MOFs) as the template. The as-prepared CuCo2O4 microspheres were first simultaneously used for H2O2 biosensing and glucose biofuel cell (GFC) as the enzyme mimic. The resulting of meso-CuCo2O4 displayed not only excellent catalytic performances to H2O2 including a super-fast response time (within 2s), a super-high sensitivity (654.23 μA mM(-1) cm(-2)) and a super-low detection limit (3nM at S/N = 3) on the sensor, but also great values in GFC as anode material with an open circuit voltage of 0...
February 1, 2018: Talanta
Zhoubing Huang, Shuqin Liu, Jiangqiao Xu, Li Yin, Fen Sun, Ningbo Zhou, Gangfeng Ouyang
The introduction of functional groups into metal organic frameworks has great potential for enhancement in adsorption performance of nitrosamines using solid phase microextraction (SPME). However, pre-functionalization and post-modification generally suffer from the same limitation that the additional functional groups occupy the free volume and thereby decreasing pore volume and special surface area. Herein, we use a modulator-induced defect-formation strategy to prepare the 8-aminocaprylic acid doped UIO-66 (Am-UIO-66) with high adsorption capacity of nitrosamines...
February 1, 2018: Talanta
Lei Zhang, Jing Zhang
Metal-organic framework derived hierarchical bayberry-like Ni@carbon hollow nanosphere/reduced graphene oxide (Ni@CHS/rGO) hybrid was synthesized by combining a simple solvothermal reaction with a further annealing treatment. 3D hierarchical bayberry-like Ni@CHS/rGO hybrid not only offered a continuous highly conductive Ni metal and graphene matrix to facilitate the charge transfer, but also allowed uptaking and releasing of electrolytes and enchanted adsorbing of targets due to a hollow structure and introduction of graphene...
February 1, 2018: Talanta
Yongming Guo, Jing Li, Shuming Chai, Jingjing Yao
Overexposure to fluoride ions (F(-)) causes serious diseases in human beings. Extensive efforts have been made to develop sensitive and selective approaches for F(-) detection and a variety of F(-) sensors have been constructed recently. The burgeoning nanotechnology has provided novel materials for F(-) analysis due to the extraordinary properties of nanomaterials. In this review, we present the recent advances in different nanomaterials-based approaches for the optical F(-) detection via colorimetric, fluorescent and chemiluminescent responses...
November 14, 2017: Nanoscale
Yongwu Peng, Meiting Zhao, Bo Chen, Zhicheng Zhang, Ying Huang, Fangna Dai, Zhuangchai Lai, Xiaoya Cui, Chaoliang Tan, Hua Zhang
The exploration of new porous hybrid materials is of great importance because of their unique properties and promising applications in separation of materials, catalysis, etc. Herein, for the first time, by integration of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), a new type of MOF@COF core-shell hybrid material, i.e., NH2 -MIL-68@TPA-COF, with high crystallinity and hierarchical pore structure, is synthesized. As a proof-of-concept application, the obtained NH2 -MIL-68@TPA-COF hybrid material is used as an effective visible-light-driven photocatalyst for the degradation of rhodamine B...
November 14, 2017: Advanced Materials
Supaporn Bouson, Atiweena Krittayavathananon, Nutthaphon Phattharasupakun, Patcharaporn Siwayaprahm, Montree Sawangphruk
Although metal-organic frameworks (MOFs) or porous coordination polymers have been widely studied, their antimicrobial activities have not yet been fully investigated. In this work, antifungal activity of copper-based benzene-tricarboxylate MOF (Cu-BTC MOF), which is water stable and industrially interesting, is investigated against Candida albicans, Aspergillus niger, Aspergillus oryzae and Fusarium oxysporum. The Cu-BTC MOF can effectively inhibit the growth rate of C. albicans and remarkably inhibit the spore growth of A...
October 2017: Royal Society Open Science
Zhengqiang Xia, Xu Jing, Cheng He, Xiaoge Wang, Chunying Duan
The production and availability of enantiomerically pure compounds that spurred the development of chiral technologies and materials are very important to the fine chemicals and pharmaceutical industries. By coordinative alignment of enantiopure guests in the metal‒organic frameworks, we reported an approach to control over the chirality of homochiral crystallization and asymmetric transformation. Synthesized by achiral triphenylamine derivatives, the chirality of silver frameworks was determined by the encapsulated enantiopure azomethine ylides, from which clear interaction patterns were observed to explore the chiral induction principles...
November 13, 2017: Scientific Reports
Zi-Rui Yang, Shang-Qing Wang, Jing Wang, Ai-Ju Zhou, Chang-Wei Xu
Carbon material containing nickel, nitrogen and sulfur (Ni-NSC) has been synthesized using metal-organic frameworks (MOFs) as precursor by annealing treatment with a size from 200 to 300 nm. Pd nanoparticles supported on the Ni-NSC (Pd/Ni-NSC) are used as electrocatalysts for ethanol oxidation in alkaline media. Due to the synergistic effect between Pd and Ni, S, N, free OH radicals can form on the surface of Ni, N and S atoms at lower potentials, which react with CH3CO intermediate species on the Pd surface to produce CH3COO(-) and release the active sites...
November 13, 2017: Scientific Reports
Douglas W Agnew, Ida M DiMucci, Alejandra Arroyave, Milan Gembicky, Curtis E Moore, Samantha N MacMillan, Arnold L Rheingold, Kyle M Lancaster, Joshua S Figueroa
A permanently porous, three-dimensional metal-organic material formed from zero-valent metal nodes is presented. Combination of ditopic m-terphenyl diisocyanide, [CNArMes2]2, and the d10 Ni(0) precursor Ni(COD)2, produces a porous metal-organic material featuring tetrahedral [Ni(CNArMes2)4]n structural sites. X-ray absorption spectroscopy provides firm evidence for the presence of Ni(0) centers, while gas-sorption and differential-scanning calorimetry analysis reveal the characteristics of a robust network with a micro-domain N2-adsorption profile...
November 13, 2017: Journal of the American Chemical Society
Ruben Demuynck, Sven M J Rogge, Louis Vanduyfhuys, Jelle Wieme, Michel Waroquier, Veronique Van Speybroeck
In order to reliably predict and understand the breathing behavior of highly flexible metal-organic frameworks from thermodynamic considerations, an accurate estimation of the free energy difference between their different metastable states is prerequisite. Herein, a variety of free energy estimation methods are thoroughly tested for their ability to construct the free energy profile as a function of the unit cell volume of MIL-53(Al). The methods comprise free energy perturbation, thermodynamic integration, umbrella sampling, metadynamics, and variationally enhanced sampling...
November 13, 2017: Journal of Chemical Theory and Computation
Jiashen Meng, Xiong Liu, Jiantao Li, Qi Li, Chuan Zhao, Lin-Han Xu, Xuanpeng Wang, Fang Liu, Wei Yang, Xiaoming Xu, Ziang Liu, Chaojiang Niu, Liqiang Mai
Earth-abundant metal-based nanostructured materials have been widely studied for potential energy conversion and storage. However, controlled synthesis of functional nanostructures with high electron conductivity, high reaction activity and structural stability is still a formidable challenge for further practical applications. Herein, for the first time, we develop a facile, efficient and general method for the oriented synthesis of precise carbon-confined nanostructures by low-pressure vapor superassembly of a thin metal-organic framework (MOF) shell and subsequent controlled pyrolysis...
November 13, 2017: Nano Letters
Haicheng Wang, Long Xiang, Wei Wei, Jing An, Jun He, Chunhong Gong, Yanglong Hou
Magnetic nanoparticles (NPs)/highly porous carbon nanocomposites, derived from metal organic frameworks (MOFs) are of great potential candidates for electromagnetic wave absorbents because of their excellent properties such as strong absorption, low density and good compatibility. In this study, a facile and effective method was developed to synthesize Co magnetic NPs/metal organic frameworks (Co NPs/ZIF-67) nanocomposites. The Co NPs/porous C composites were subsequently obtained by annealing the Co NPs/ZIF-67 nanocomposites at different temperatures under inert atmosphere...
November 13, 2017: ACS Applied Materials & Interfaces
Rui Zhai, Yifeng Yuan, Fenglong Jiao, Feiran Hao, Xiang Fang, Yangjun Zhang, Xiaohong Qian
Mass spectrometry (MS) based bottom-up strategy is now the first choice for proteomics analysis. In this process, highly efficient and complete enzymatic degradation of protein samples is extremely important to achieve in-depth protein coverage and high-throughput protein profiling. However, conventional in-solution digestion suffer from long digestion time and enzyme autolysis that limit the protein sample processing throughput and identification accuracy. Here, we developed a novel type of magnetic metal organic frameworks (MOFs)-based immobilized enzyme reactor, Fe3O4@DOTA-ZIF-90-trypsin...
November 22, 2017: Analytica Chimica Acta
Xiuling Zhang, Na Wang, Longlong Geng, Junna Fu, Hui Hu, Dashuai Zhang, Baoyong Zhu, Jesse Carozza, Haixiang Han
Design and synthesis of low-cost catalysts with high activity and stability for hydrogenation reactions is an important research area of applied catalysis. In this work, we present a kind of ultrafine cobalt oxides encapsulated by N-doped carbon (donated as CoOx/CN) as efficient catalysts for hydrogenation of 4-nitrophenol (4-NP) process. The CoOx/CN was fabricated through a pyrolysis strategy using an N-containing metal-organic framework (Co-MOF) as precursor followed by a fine thermal-treatment. With an optimized pyrolysis temperature of 500 °C, the CoOx species present as ultrafine particles highly dispersed in the obtained catalyst (CoOx/CN-500)...
November 7, 2017: Journal of Colloid and Interface Science
Ryuichi Murase, Chanel F Leong, Deanna M D'Alessandro
The fundamentally important phenomenon of mixed valency has been discussed in detail over the past 50 years, predominantly in the context of dinuclear complexes, which are used as model systems for understanding electron delocalization in more complex biological and physical systems. Very recently, mixed valency has been shown to be an important mechanism for charge transfer, leading to delocalization and conductivity in two- and three-dimensional framework materials such as metal-organic frameworks and related systems including covalent organic frameworks and semicrystalline semiconducting metal-organic graphenes...
November 10, 2017: Inorganic Chemistry
Charity C Epley, Madeline D Love, Amanda J Morris
Exploring defect sites in metal-organic framework materials has quickly become an interesting topic of discussion in the literature. With reports of the enhancement of material properties with increasing defect sites, we were interested in probing the defect nature of UiO-AZB (UiO = University of Oslo, AZB = 4,4'-azobenzenedicarboxylate) nanoparticles. In this report, we investigate the use of acetic, formic, and benzoic acids as the modulators to prepare UiO-AZB. The results of (1)H NMR techniques and BET surface area analysis elucidate the extent of defects in our samples and are provided along with detailed discussions of the observed experimental trends...
November 9, 2017: Inorganic Chemistry
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