ACS Applied Nano Materials
·
2021
·
IF 5.097
Ying Li,Shujuan Li,Min Bao,Linqun Zhang,Carlo Carraro,Roya Maboudian,Anran Liu,Wei Wei,Yuanjian Zhang,Songqin Liu
Nanomaterials possessing intrinsic enzyme-mimetic activity are becoming an important topic of current research. However, their enzyme-mimetic activity is limited by the particle size of the nanomaterials. In this study, Pd nanoclusters with an average size of 1.4 nm are synthesized by using a metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), as a matrix via an impregnation-reaction method. By virtue of the confined channels of ZIF-8 and the strong chemical interaction between the Pd nanoclusters and ZIF-8 framework, the Pd nanoclusters show a high dispersity and stability. The obtained Pd@ZIF-8 is proven to have enhanced intrinsic peroxidase-like activity, showing Michaelis–Menten constants (Km) as high as 0.13 mM for 3,3′,5,5′-tetramethylbenzidine and 14.02 mM for hydrogen peroxide. Colorimetric testing and electron spin resonance spectra reveal that radicals are generated during the catalytic process of peroxidase-like Pd@ZIF-8 toward H2O2. With the addition of glucose or cholesterol oxidase, the Pd@ZIF-8 can be utilized to construct a highly selective and sensitive fluorescent sensor for glucose and cholesterol, exhibiting a detection limit of 0.10 and 0.092 μΜ, respectively. Additionally, the proposed fluorescent platform exhibits the capability to detect glucose and cholesterol in serum samples with satisfactory recovery, indicating potential application prospects in biochemical analysis.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Xilu Hong,Zong Lu,Yali Zhao,Luxi Lyu,Li Ding,Yanying Wei,Haihui Wang
As one of the green, renewable, and clean energy resources, hydrogen is widely developed and utilized throughout the world. Highly efficient membrane separation for hydrogen production is required to give promising gas permeance with enough H 2 selectivity. The membranes are desired to be produced in large-scale, fast and facile methods. Here we report for the first time a kind of freestanding MXene-ZIF-8 dual-layered membrane for hydrogen separation. Fast synthesis of such membranes is realized by combining electrophoretic deposition (EPD) and fast current-driven synthesis (FCDS), achieving the assemble of MXene layer and growth of ZIF-8 layer, respectively, overcoming the traditional time-consuming vacuum filtration methods and solvothermal synthesis . The MXene-ZIF-8 dual-layered membrane prepared within 20 min exhibits significantly improved gas separation performance, whose H 2 /CO 2 selectivity increases from 44 for the pristine MXene membrane to 77 with H 2 permeance of 5.97 × 10 −8 mol m −2 s −1 Pa −1 . This concept of structure design of membrane can also be extended to other dual-layered membranes, including various 2D nanosheet layers combined with different MOF layers.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Tengyang Zhu,Sheng Xu,Fen Yu,Xi Yu,Yan Wang
In this study, ZIF-8@GO composites with continuous inner channels for ethanol molecules were prepared by the in-situ growth of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles onto the surface of graphene oxide (GO) nanosheets , and filled into polydimethylsiloxane (PDMS) matrix to fabricate PDMS/ZIF-8@GO mixed matrix membranes (MMMs) for ethanol recovery via pervaporation . The as-prepared ZIF-8@GO composites and PDMS/ZIF-8@GO MMMs were characterized by various techniques. The results showed that ZIF-8 nanoparticles were uniformly dispersed on the surface of GO nanosheets and the hydrophobicity of ZIF-8@GO composites was stronger than GO due to the surface modification of GO by hydrophobic ZIF-8. Moreover, ZIF-8@GO composites as the filler not only exhibited the excellent compatibility with PDMS but also showed the good dispersion in PDMS matrix as compared to ZIF-8 nanoparticles. Therefore, ZIF-8@GO-based MMMs showed better separation performance than ZIF-8-based MMMs. The pervaporation performance of PDMS/ZIF-8@GO MMMs was studied by adjusting the filler type, particle loading, membrane thickness, and feed temperature. The optimized PDMS/ZIF-8@GO MMMs displayed a prominent separation factor of 22.2 with a total flux of 443.8 g/m 2 h with 5 wt% ethanol aqueous solution at 40 °C, and therefore the superior pervaporation performance to most other PDMS-based MMMs. The excellent pervaporation results were attributed to the synergistic effect of GO nanosheet as a strong barrier and hydrophobic ZIF-8 nanoparticles with the continuous inner channels. The synergistic effect of hybrid particles may provide valuable guidance to the development of high-performance PDMS-based MMMs for pervaporation recovery of various organic compounds.
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 21
·期 45
·6935-6944
·
IF 3.382
Qunling Fang,Yuhang Sun,Jinyu Duan,Linfeng Bai,Kezhu Xu,Qinshan Xiong,Huajian Xu,Ken Cham-Fai Leung,Ailing Hui,Shouhu Xuan
Metal–organic framework (MOF)-derived nanostructures exhibit wonderful characteristics and possess broad application potential by modulating the complex composition and inner nanostructure. Although various MOF-based nanocomposites have been successfully developed, a facile method that can easily modulate the structure-dependent chemical components of the MOF-derived hybrids remains a challenge. By coating zeolitic imidazolate framework-8 (ZIF-8) with Au/polydopamine (Au/PDA) via in situ redox-oxidation polymerization of HAuCl4 and dopamine, it was found that the ZIF-8 templates were simultaneously etched off to give Au/PDA hybrid microcapsules with a cubic shape. This one-step sacrificial templating process followed a competing chelation between gold ions and Zn2+ cations to 2-methylimidazole and PDA; thus, both the hollow and the yolk-like hybrid cubic microcapsules were controllably obtained by varying the synthetic dynamics. Owing to the hollow nature, penetrated PDA shell, well-distributed Au nanocrystals, and unique stable nanostructure, the non-spherical Au/PDA hybrid cubic microcapsules showed high performance in catalyzing the reduction of 4-nitrophenol as well as adsorption/release of ibuprofen as a model drug. Moreover, this simple strategy offers a controllable design in developing multifunctional nanocomposites with definite inner nanostructures and activities for nanocatalysis, drug delivery, energy storage etc.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Long Zhou,Na Li,Gary Owens,Zuliang Chen
Many wastewaters commonly contain complex mixtures of both antibiotics and heavy metals, where the simultaneous removal of these mixed contaminants is still a challenge. In this paper, ZIF-8, a metal-organic framework material, was proposed as a potential absorbent to simultaneously remove norfloxacin and copper from wastewater. Batch adsorption experiments showed that ZIF-8 could simultaneously remove 95.4% of Cu and 80.3% of norfloxacin. ZIF-8 was characterized before and after the removal of the mixed contaminants. X-ray powder diffraction (XRD) showed that ZIF-8 was synthesized successfully and maintained a stable structure after contaminant adsorption. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) both suggested that contaminants were partially adsorbed on the surface of ZIF-8. X-ray photoelectron spectroscopy (XPS) also indicated the presence of both carboxyl and Cu on the ZIF-8 surface confirming that a mixture of contaminants was adsorbed. For both contaminants, adsorption followed pseudo-second-order kinetics and best fit the Freundlich adsorption model with correlation coefficients (R 2 ) of 0.973 and 0.994, for copper and norfloxacin, respectively. Finally, removal mechanisms for copper and norfloxacin by ZIF-8 were proposed. For Cu, the adsorption process on ZIF-8 was mainly due to ion exchange, whereas electrostatic interactions and π-π stacking may be responsible for norfloxacin adsorption. Overall this study demonstrated that ZIF-8 was a promising material for the treatment of wastewater containing mixtures of organic and metallic contaminants.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Zhihao Si,Di Cai,Shufeng Li,Changwei Zhang,Peiyong Qin,Tianwei Tan
Recently, zeolitic imidazolate framework-8 (ZIF-8) has been recognized as one of the most potential doping particles for pervaporation separation of organics because of its unique pore structure and high surface area. However, in this work, ZIF-8-based mixed matrix membrane (MMM) was found to have poor stability in separating acetone-butanol-ethanol (ABE) fermentation broth due to the organic acids caused the degradation of ZIF-8 framework. To improve the stability of ZIF-8-based MMM in practical application, ZIF-8-derived nanoporous carbon (ZNC) was prepared via direct carbonization and used to replace ZIF-8 in MMM. Results indicated the acid-stability, specific surface area and pore volume of ZNC were all remarkably improved compared with those of ZIF-8. The ZNC-based MMM showed high hydrophobicity and good compatibility between particles and polymer. More attractively, during 100 h of continuous operation for ABE recovery from fermentation broth, ZNC incorporated MMM exhibited a stable performance with an average total flux of 1870 g m −2 h −1 and a n -butanol separation factor of 20.
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Zhenghong Zhao,Tianran Lin,Wenren Liu,Li Hou,Fanggui Ye,Shulin Zhao
Zeolitic imidazolate framework-8 (ZIF-8) has become one of the most typical examples of nanostructures for multi-enzyme immobilization due to its economical, mild and easy synthesis process. However, ZIF-8 nanocrystals are easily decomposed under acidic conditions. To solve this problem, the Fe-polydopamine (Fe-PDA) was bonded with ZIF-8 surface to form [email protected] hybrid shell with good stability. Based on this, we developed glucose [email protected] @Fe-PDA ( [email protected] @Fe-PDA) integrated nanozymes (INAzymes) with cascade reactions via a mild and environmentally friendly method. In order to synthesize the INAzymes, GOx was first embedded in ZIF-8 by coprecipitation ( [email protected] ), and then [email protected] was bonded with Fe-PDA, which acted as a peroxidase mimic. The [email protected] hybrid shell protected the INAzymes nanostructure from degradation under acidic conditions, which results in good chemical stability of the [email protected] @Fe-PDA. In the INAzymes system, glucose is converted to gluconic acid by GOx in the presence of oxygen to produce H 2 O 2 as an intermediate. The H 2 O 2 reacts rapidly with Fe-PDA to generate OH, which oxidizes 3,3′,5,5′-tetramethylbenzidine (TMB). The UV absorbance of oxidized TMB is directly proportional to the glucose concentration, and has a good linear relationship in the range of 5.0–100.0 μM glucose with detection limit of 1.1 μM. The INAzymes system has been successfully applied to rapid colorimetric detection of blood glucose levels. The INAzymes system exhibits high catalytic activity, excellent sensitivity, and enhanced chemical stability, playing great promise in clinical diagnosis and biosensing.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2019
·Vol. 65
·期 8
·e16620
·
IF 3.463
Xiaoxu Zhao,Hao Zhang,Sheng Xu,Yan Wang
In this study, a novel covalent-assisted seeding method is developed to fabricate well-intergrown ZIF-8 membrane on polyimide (PI) substrate with imidazole-2-carboxaldehyde (ICA) as the covalent agent between ZIF-8 layer and PI substrate. Compared to ethylenediamine-crosslinked PI membrane and ZIF-8/PI membrane synthesized without covalent-assisted seeding method, ZIF-8/PI membrane synthesized with ICA covalent-assisted seeding method shows improved pervaporation performance for isopropanol dehydration. Subsequent surface coating with polydimethylsiloxane or polydopamine is applied to mitigate the grain boundary of ZIF-8/PI membrane, which results in a further performance enhancement. The morphologies and physicochemical properties of the resultant membranes are characterized by scanning electron microscope, attenuated total reflectance-Fourier transform infrared, X-ray diffraction, and water contact angle. The effect of operation temperature on the separation performance is also carried out. This work demonstrates the novel covalent-assisted seeding method for the preparation of ZIF-8 membrane with high-performance, which may hold a great potential for various ZIF membranes separation applications.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Atian Xie,Jiuyun Cui,Jin Yang,Yangyang Chen,Jihui Lang,Chunxiang Li,Yongsheng Yan,Jiangdong Dai
The oil/water emulsion separation has become a thorny problem worldwide. Membrane separation based on superwetting materials has attracted immense attention in the domain of oil/water separation, while the single wettability severely limits their applications for treatment of different types oily wastewater. In this work, ZIF-8 modified membrane (RC@PDA/ZIF-8) is prepared via coordination-driven in situ self-assembly ZIF-8 on polydopamine (PDA) coated regenerated cellulose membrane (RC). The surface wettability of resultant membrane can be switched between underwater superoleophobicity and underoil (super)hydrophobicity by water or oils prewetted without additional external stimuli, which is suitable for controllable oil/water emulsion separation. Moreover, this membrane also displays superior separation capacity as high as above 99% and good flux for various oil-in-water and water-in-oil emulsions. Furthermore, the membrane shows good recyclability that it can retain high separation efficiency (98.5%) and flux after at least 10 times cycles. Also, the controllable emulsion separation mechanisms are analyzed and elucidated in detail. This ZIF-8 modified membrane with easy preparation and simple operation exhibits excellent separation efficiency and recyclability for controllable oil/water emulsion separation. Our work demonstrates MOFs-based membrane has potential applications including controllable oil/water separation and fuel purification.
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Pengfang Zhang,Yun Xiao,Hui Sun,Xiaoping Dai,Xin Zhang,Haixia Su,Yuchen Qin,Daowei Gao,Axiang Jin,Hai Wang,Xiubing Wang,Shigang Sun
Morphology-controlled synthesis of metal–organic frameworks (MOFs) is of tremendous importance to understand the morphology–structure–property relationships. Although great emphasis has been placed on the controllable synthesis of MOFs, the preparation of hollow and nanoframe-like MOFs, especially using the microwave irradiation method, remains a great challenge. In the present work, we report microwave-assisted synthesis of hollow butterfly and ring zeolitic imidazolate framework-8 (ZIF-8) with the stimuli of Ni ions. Interestingly, the sphere, butterfly, and fiber ZIF-8 catalysts were also fabricated when adjusting the weight ratio of Zn and Ni resources. Specifically, sphere, butterfly, hollow butterfly, and ring particles have maintained the ZIF-8 structure. On the basis of the time sequential experiments, we inferred that the formation of hollow butterfly and ring particles is driven by the change of surface energy. The Knoevenagel reaction was carried out to explore the catalytic activity of these ZIF materials. The ring particles with ZIF-8 structure showed the highest catalytic activity. The open structure, thin walls, and the amount of basicity have been extensively discussed to shed light on the superior catalytic performance of ring particles.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Wenji Zheng,Rui Ding,Kai Yang,Yan Dai,Xiaoming Yan,Gaohong He
Poly (ether- block -amide) (Pebax) based mixed matrix membranes (MMMs) were prepared by using size-tunable ZIF-8 nanoparticles as fillers. ZIF-8 nanoparticles with sizes of 40, 60, 90 and 110 nm (ZIF-8-40, ZIF-8-60, ZIF-8-90 and ZIF-8-110) were synthesized in microemulsion by controlling the ratio of Zn 2+ to Hmim (1:16, 1:8, 1:5, 1:2). And they were distributed uniformly in Pebax matrix without obvious agglomerations and defects at the loading of 0–20 wt.%, which was confirmed by field-emission scanning electron microscopy (FE-SEM). The incorporation of ZIF-8 resulted in a significant improvement in CO 2 permeability and the CO 2 /N 2 selectivity increased with the BET surface area of ZIF-8 increasing. The enhanced permeability is attributed to an improvement in the free volume of the polymer induced by larger sized ZIF-8, while the increased selectivity results from the high specific surface area of large sized ZIF-8, which can provide more active sites for CO 2 capture and great mass transfer resistance for N 2 . At 5 wt.% loading of ZIF-8-90, the MMM presents the best separation performance with CO 2 permeability of 99.7 Barrer and CO 2 /N 2 selectivity of 59.6, both of which are increased by about 25% by comparison to the pure Pebax membrane. The present study provides an effective way to obtain size-controlled ZIF-8 fillers and high separation performances of Pebax based MMMs.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Baokai Ma,Ling-Zhi Cheong,Xinchu Weng,Chin-Ping Tan,Cai Shen
Organophosphorus pesticides especially p -nitrophenyl pesticides (methyl parathion) have neurotoxic effects and it is a difficult to remove organophosphorus pesticides residues from contaminated water. Present work has developed a sensitive, direct and rapid lipase@ZIF-8/chitosan/glassy carbon electrode (GCE) and lipase@amine-modified ZIF-8(An-ZIF-8)/chitosan/GCE biosensors for detection of methyl parathion . ZIF-8 and An-ZIF-8 nanoparticles which are a type of metal-organic frameworks with large surface area and high porosity have been facilely prepared under mild biocompatible conditions and used as lipase immobilization matrixes in the biosensors. The optimized lipase@ZIF-8/chitosan/GCE and lipase@An-ZIF-8/chitosan/GCE biosensors can detect methyl parathion with a wide linear range, good repeatability, recovery and limit of detection as low as 0.28 μM. The as-prepared biosensors can be stored in 0.05 M PBS (pH 7) at 4 °C and reused for at least 20 days with a retainment of at least 80% of its initial response to methyl parathion. This indicated that both ZIF-8/chitosan and An-ZIF-8/chitosan are suitable for immobilization of lipase that favors generation of p -nitrophenol from methyl parathion; and subsequent electrochemical oxidation and electron transfer of the p -nitrophenol.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）