Search query: ZIF-67

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abstract: Abstract Metal organic framework (MOF) is one of the most promising precursors for the fabrication of advanced photo semiconductors or cocatalysts due to its diverse structures and unique properties. However, the primitive MOF can not show greater potential and application value. Here Co ZIF 67 dodecahedron was controllably carved via the different ways for efficiently boosting the photo catalytic property of hydrogen evolution. This reasonable design can not only preserve polyhedron characteristics with the large specific surface area of ZIF 67, but also improve H2 evolution performance in Eosin Y sensitization system, which depends on the enhanced electronegativity of the surface of ZIF 6 derived polyhedrons and the quite strong adsorption of H and H2O by Co site. Meanwhile, ligand group or hetero atom adjacent to metal Co atom owing to the introduction of electronegative heteroatoms overturns the inherent structure and properties of ZIF 67 to a certain extent thereby rearranging the electron distribution and improving transfer efficiency of charge carriers. Additionally, the structural evolution of ZIF 67 constructs an efficient transport channels for migration of electron, which eliminates the resistance to be overcome when electrons migrate from the inside of a semiconductor to the surface. And the increase of optical absorption density caused by hyperchromicity effect is also a factor that can not be ignored for evolving the co catalytic performance of ZIF 67.
author_names: Yanbing Li

Zhiliang Jin

Tiansheng Zhao
title: Performance of ZIF 67 Derived fold polyhedrons for enhanced photocatalytic hydrogen evolution
year: 2020

abstract: Abstract Engineering non precious metal electrocatalysts that accompanied with excellent performance toward oxygen evolution reaction (OER) remains a great challenge. Herein, a class of CoSe2 nano vesicle that derived from ZIF 67 nanocubes is fabricated by a facile one pot hydrothermal method. Benefitting from the hollow structure, abundant oxygen vacancies, strong synergistic effect between Co and Se, and facilitated electron transfer rate, the optimized CoSe2 30 exhibits excellent OER performance with a low overpotential of 287 mV at the current density of 10 mA cm 2, and small Tafel slope of 54.3 mV dec 1, which is much superior to the reported OER electrocatalyst derived from ZIF 67 via complicated prepared method. In addition, these electrocatalysts can also maintain original current density and voltage after long term chronoamperometry and chronopotentiometry tests, respectively. This work demonstrates a favorable hydrothermal method for transforming cubic ZIF 67 nanocrystal structure into hollow CoSe2 nano vesicle with excellent electrocatalytic performance for OER and thus opens up a sunshine road for the practical applications of water electrolysis.
author_names: Zhao Li

Zizhan Jiang

Wenyou Zhu

Changchun He

Pingshan Wang

Xiang Wang

Tongxiang Li

Lin Tian
title: Facile preparation of CoSe2 nano vesicle derived from ZIF 67 and their application for efficient water oxidation
year: 2020

abstract: Potassium ion batteries (KIB) have become a compelling energy storage system owing to their cost effectiveness and the high abundance of potassium in comparison with lithium. However, its practical applications have been thwarted by a series of challenges, including marked volume expansion and sluggish reaction kinetics caused by the large radius of potassium ions. In line with this, the exploration of reliable anode materials affording high electrical conductivity, sufficient active sites, and structural robustness is the key. The synthesis of ZIF 8@ZIF 67 derived nitrogen doped porous carbon confined CoP polyhedron architectures (NC@CoP/NC) to function as innovative KIB anode materials is reported. Such composites enable an outstanding rate performance to harvest a capacity of 200 mAh g 1 at 2000 mA g 1 Additionally, a high cycling stability can be gained by maintaining a high capacity retention of 93% after 100 cycles at 100 mA g 1 Furthermore, the potassium ion storage mechanism of the NC@CoP/NC anode is systematically probed through theoretical simulations and experimental characterization. This contribution may offer an innovative and feasible route of emerging anode design toward high performance KIBs.
author_names: Yuyang Yi

Wen Zhao

Zhihan Zeng

Chaohui Wei

Chen Lu

Yuanlong Shao

Wenyue Guo

Shi Xue Dou

Jingyu Sun
title: ZIF 8@ZIF 67 Derived Nitrogen Doped Porous Carbon Confined CoP Polyhedron Targeting Superior Potassium Ion Storage.
venue: Small
year: 2020

abstract: Heterogeneous catalysts with precise surface and interface structures are of great interest to decipher the structure property relationships and maintain remarkable stability while achieving high activity. Here, we report the design and fabrication of the new sandwich composites ZIF 8@Au25@ZIF 67[tkn] and ZIF 8@Au25@ZIF 8[tkn] [tkn thickness of shell] by coordination assisted self assembly with well defined structures and interfaces. The composites ZIF 8@Au25@ZIF 67 efficiently catalyzed both 4 nitrophenol reduction and of terminal alkyne carboxylation with CO2 un der ambient conditions with remarkably improved activity and stability, compared to the simple components Au25/ZIF 8 and Au25@ZIF 8, highlighting the highly useful function of the ultrathin shell. In addition, the performances of these compo site sandwich catalysts are conveniently regulated by the shell thickness. This concept and achievements should open a new avenue to the targeted design of well defined nanocatalysts with enhanced activities and stabilities for challenging reac tions.
author_names: Yapei Yun

Hongting Sheng

Kang Bao

Li Xu

Yuanyuan Zhang

Didier Astruc

Manzhou Zhu
title: Design and Remarkable Efficiency of the Robust Sandwich Cluster Composite Nanocatalysts ZIF 8@Au25@ZIF 67.
venue: Journal of the American Chemical Society
year: 2020

abstract: Abstract For supercapacitors, development of electrode materials with superior electrochemical performance is urgently needed. Herein, we synthesized novel nickel cobalt sulfide (NiCo2S4) hollow cages as electrode materials for supercapacitors. The NiCo2S4 hollow cages possess a hollow interior and mesoporous structure, which could shorten ion diffusion distance and provide plentiful electroactive sites. Thanks to the appealing structures, the NiCo2S4 hollow cages exhibit an appealing capacitance of 1382 F g 1 at 1 A g 1. Furthermore, asymmetric supercapacitors (ASCs) are fabricated with the synthesized NiCo2S4 and active carbon (AC) as electrodes. The ASC shows an energy density of 35.3 Wh kg 1 at a power density of 750 W kg 1 and an outstanding cycling stability of 79% retention after 10,000 cycles. The excellent performance of NiCo2S4 hollow cages makes them promising candidates in supercapacitors.
author_names: Pengfei Cai

Tao Liu

Liu Yang Zhang

Bei Cheng

Jiaguo Yu
title: ZIF 67 derived nickel cobalt sulfide hollow cages for high performance supercapacitors
year: 2020

abstract: Abstract Utilized Zn/Co based metal organic framework, we successfully fabricate 1D N doped porous carbon nanofibers anchoring amorphous and graphite carbon encapsulated CoS2 nanoparticles, using a facile electrospinning strategy combined with annealing treatment. Remarkably, the composite as superior anode for sodium ion battery is rationally designed, and also exhibit enhanced Na storage performance. The composite shows a large specific capacity of 876 mAh g 1 at 100 mA g 1 in the initial cycles and an outstanding long term performance (148 mAh g 1 at a current density of 3.2 A g 1 over 1000 cycles) The improved electrochemical performance is ascribed to the 1D porous carbon nanofibers structure and the amorphous and graphite carbon coating, which can relatively inhibit agglomeration of CoS2 nanoparticles, mitigate the volume of the material changes in the process of circulation and provide stabilized electrical conductivity. This research paves the way for extending the 1D metal sulfides and metal organic framework composites toward potential applications.
author_names: Wenming Zhang

Ziwei Yue

Qiming Wang

Xiaoxi Zeng

Chaochao Fu

Qing Li

Xiaoting Li

Lide Fang

Liang Li
title: Carbon encapsulated CoS2 nanoparticles anchored on N doped carbon nanofibers derived from ZIF 8/ZIF 67 as anode for sodium ion batteries
year: 2020

abstract: Abstract This study applies two isostructural zeolitic imidazolate frameworks (ZIF 8 and ZIF 67) to rapidly adsorb and remove sulfur mustard (HD) a chemical warfare agent. Because HD is extremely toxic, some of the studies were conducted using an HD simulant, 2 chloroethyl ethyl sulfide (CEES) to understand the effect of solvent polarity on adsorption. Further, CEES and real HD were subsequently adsorbed and removed from aqueous solutions using ZIF 8 or ZIF 67. The adsorption abilities of ZIF 8 and ZIF 67 positively correlated with the polarity of the solvent. In addition, 97% of CEES (2.5 mg in 1 mL) was rapidly adsorbed by ZIF 8 and ZIF 67 within 1 min at 25 degC in a 9:1 (v/v) water/ethanol solution. ZIF 8 and ZIF 67 were also successfully fabricated on cotton, which was removed more than 95% of contaminants from substrates contaminated with the HD simulant. We believe that this work will encourage the development of ZIFs for chemical warfare defense.
author_names: Ye Rim Son

Sam Gon Ryu

Hyun Sung Kim
title: Rapid adsorption and removal of sulfur mustard with zeolitic imidazolate frameworks ZIF 8 and ZIF 67
venue: Microporous and Mesoporous Materials
year: 2020

abstract: Abstract Given the remarkable performances of metal frame works (MOFs) and ferrocene containing polymers (FCPs) in electronic devices, the research on integration of structure and function for collaborative optimization of electromagnetic wave (EMW) absorption are still missing. Herein, surface grafting and main chain polymerization methods have been employed on the FCPs modifying zeolitic imidazolate framework 67 (ZIF 67) respectively. Polydopamine coated ZIF 67 was precursor for grafting type products (ZIF 67@PDA Fc) while poly (vinyl ferrocene) was for main chain type products (ZIF 67@PVF) Furthermore, the calcined products, polyhedron capsules structured Co3O4@C@a Fe2O3 and Co3O4/a Fe2O3@C microwave absorbers were obtained from ZIF 67@PDA Fc and ZIF 67@PVF for higher performance EMW absorption. The crystal, morphological and chemical structure was detected via XRD, SEM, TEM, FTIR, Raman, XPS techniques. The EMW absorbability was calculated according to transmission line theory. In particular, the minimum reflection loss (RLmin) of Co3O4@C@a Fe2O3 reached 52.2 dB at the thickness of 3.7 mm with effective absorption band (fE) 4.4 GHz. It is worth emphasized that the broadest fE was 6.6 GHz obtained at 2.5 mm with RLmin reaching 38.4 dB. Additionally, the EMW absorption mechanism was also studied based on the dielectric and magnetic properties. This investigation will push forward further research and practical application of metal organic compounds based composites.
author_names: Zhenguo Gao

Jiaoqiang Zhang

Shijie Zhang

Di Lan

Zehao Zhao

Kaichang Kou
title: Strategies for electromagnetic wave absorbers derived from zeolite imidazole framework (ZIF 67) with ferrocene containing polymers
year: 2020

abstract: Abstract The fabricated intercalated structure composed of a Co based zeolitic imidazolate framework (ZIF 67) and expanded graphite (EG) has been prepared using a facile and simple one pot hydrothermal reaction. This framework was used to detect heavy metal ions (HMIs) via a square wave anodic stripping voltammetry (SWASV) method for the first time. Here, the composite material is useful for the selective electrochemical detection of nanomolar Cd2+ Pb2+ Cu2+ and Hg2+ in aqueous solutions simultaneously or individually. The operational parameters such as pH, electrolyte, deposition potential, and deposition time were optimized to detect various HMIs. The electrochemical properties and applications of the modified electrode were also studied. The constructed electrochemical sensor displays good performance with a large electrochemically active surface areas, high sensitivity and low limit of detection (LOD) These impressive features originate from the synergistic effects of ZIF 67 and EG. This study proposes a new strategy for heavy metal ion detection using a novel morphology of a metal organic framework (MOF) composite.
author_names: Laifeng Ma

Xueyi Zhang

Muhammad Ikram

Mohib Ullah

Hongyuan Wu

Keying Shi
title: Controllable synthesis of an intercalated ZIF 67/EG structure for the detection of ultratrace Cd2+ Cu2+ Hg2+ and Pb2+ ions
year: 2020

abstract: Abstract Mixed matrix membranes (MMMs) based on metal organic frameworks (MOFs) have proven to have high separation performance, which has great potential in separation applications. However, unsatisfactory hydrothermal stability is the Achilles' heel of MOFs in practical applications, which seriously hinders the development of MOF based MMMs. Under the advantage of crystal anisotropy, a morphology regulation strategy without post treatment is presented for the first time to efficiently improve the stability of MOF fillers in aqueous solution. Contrary to the regular dodecahedron ZIF 67 crystals, the [211] oriented ZIF 67 nanosheets (NS) can maintain an ordered microporous framework integrally in the aqueous solution of membrane preparation. The exposed [211] crystal face exhibits enhanced stability due to a lower proportion of Co N bond and higher surface atomic density. The flake morphology of ZIF 67 with economic incorporation (5.0 wt offers the MMMs significantly enhanced CO2 permeability of 139.4 barrer and CO2/N2 ideal selectivity of 73.2, improved by 50.7% and 76.0% compared with the pristine polymer membrane. This strategy provides a new idea for improving the hydrothermal stability of MOF materials and extends their separation applications under aqueous conditions.
author_names: Shou Feng

Mengqi Bu

Jiangtao Pang

Weidong Fan

Lili Fan

Haoru Zhao

Gene Jaehyoung Yang

Hailing Guo

Guodong Kong

Haixiang Sun

Zixi Kang

Daofeng Sun
title: Hydrothermal stable ZIF 67 nanosheets via morphology regulation strategy to construct mixed matrix membrane for gas separation
year: 2020