High-aspect ratio zeolitic imidazolate framework (ZIF) nanoplates for hydrocarbon separation membranes.
Ontology highlight
ABSTRACT:
SUBMITTER: Kwon O
PROVIDER: S-EPMC8730619 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:RHO zeolitic imidazolate framework (ZIF), Zn1.33 (O.OH)0.33 (nim)1.167 (pur), crystals with a rhombic dodecahedral morphology were synthesized by a solvothermal process. The growth of the crystals was studied over time using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD) and Brunauer-Emmett-Teller (BET) analyses, and a reversed crystal growth mechanism was revealed. Initially, precursor materials joined together to form disordered aggregates, which then underwent surface recrystallization forming a core-shell structure, in which a disordered core is encased in a layer of denser, less porous crystal. When the growth continued, the shell became less and less porous, until it was a layer of true single crystal. The crystallization then extended from the surface to the core over a six-week period until, eventually, true single crystals were formed.
| S-EPMC4736437 | biostudies-literature
Project description:Adsorption and photodegradation of rhodamine B by ZIF-8 nanocrystals were studied using spectroscopic techniques coupled with density functional theory (DFT) cluster calculations. A fast adsorption rate was observed in the dark, but upon exposure to visible light or UV irradiation the adsorption rate noticeably increased. Although several studies previously reported this phenomenon involving bulk ZIF-8 powder, this is the first mechanistic study to our knowledge that demonstrates adsorption and degradation of rhodamine B by nanosized ZIF-8 under various light conditions. The combined study of N2 sorption pore analysis and surface-sensitive X-ray photoelectron spectroscopy (XPS) confirmed the surface adsorption was mainly due to the open metal sites and surface groups of nanoporous ZIF-8. The fluorescence studies suggested ZIF-8 nanocrystals were able to generate hydroxyl radicals in water but only under UV illumination. The work presented here provides an insight into understanding nanoscale metal-organic frameworks (MOFs) in the removal of organic molecules from wastewater.
| S-EPMC6088371 | biostudies-literature
Project description:The development of wide-spectrum responsive photocatalysts for efficient formaldehyde (HCHO) removal is highly desired yet remains a great challenge. Here we successfully converted zeolitic imidazolate framework-8 (ZIF-8), one of the most well-studied metal-organic frameworks (MOFs), from routine ultraviolet-driven to novel broad-spectrum-driven photocatalyst via a facile thermal treatment. The isocyanate groups (-N[double bond, length as m-dash]C[double bond, length as m-dash]O) formed in the thermally treated ZIF-8 (ZIF-8-T) is crucial in enabling the superior photocatalytic performance in formaldehyde degradation. Specifically, the best-performing ZIF-8-T sample showed around 2.1 and 9.4 times the HCHO adsorption amount and the solar photocatalytic degradation rate, respectively, of pristine ZIF-8. In addition, ZIF-8-T exhibited visible light (λ ≥ 400 nm) photocatalytic HCHO degradation performance, photo-converting 72% and nearly 100% of 20 ppm and 10 ppm HCHO within 1 hour, respectively. This work affords new insights and knowledge that inspire and inform the design and development of MOF-based photocatalysts with broad-spectrum responses for efficient air purification operations.
| S-EPMC8159372 | biostudies-literature
Project description:The development of novel electrode materials for rapid and sensitive detection of neurotransmitters in the human body is of great significance for early disease diagnosis and personalized therapy. Herein, gold nanorod@zeolitic imidazolate framework-8 (AuNR@ZIF-8) core-shell nanostructures were prepared by controlled encapsulation of gold nanorods within a ZIF-8 assembly. The designed AuNR@ZIF-8 nanostructures have uniform morphology, good dispersion, a large specific surface area, and an average size of roughly 175 nm. Compared with individual ZIF-8 and AuNR-modified electrodes, the obtained core-shell-structured AuNR@ZIF-8 nanocomposite structure-modified electrode shows excellent electrocatalytic performance in the determination of dopamine (DA) and serotonin (ST). The designed AuNR@ZIF-8 exhibited a wide linear range of 0.1-50 μM and low detection limit (LOD, 0.03 μM, S/N = 3) for the determination of DA, as well as a linear range of 0.1-25 μM and low LOD (0.007 μM, S/N = 3) for monitoring ST. The improved performance is attributed to the synergistic effect of the high conductivity of AuNRs and multiple catalytic sites of ZIF-8. The good electroanalytical ability of AuNR@ZIF-8 for detection of DA and ST can provide a guide to efficiently and rapidly monitor other neurotransmitters and construct novel electrochemical sensors.
| S-EPMC8655944 | biostudies-literature
Project description:Zeolitic imidazolate frameworks, like ZIF-8 and related structures, have shown great potential for the capture of carbon dioxide. Modifying their structure by exchanging part of the constituent organic ligands is a proven method for enhancing the capacity to absorb CO2. In this work, we performed solvent-assisted ligand exchange (SALE) on nanosized ZIF-8 (nZIF-8) with a series of functionalized imidazole derivatives (exchange percentages, after 24 h): 2-bromoimidazole (19%), 2-chloroimidazole (29%), 2-trifluoromethylbenzimidazole (4%), 2-mercaptobenzimidazole (4%), and 2-nitroimidazole (54%). The sodalite topology and porosity of nZIF-8 were maintained with all SALE modifications. Low-pressure CO2 adsorption of nZIF-8 (38.5 cm3 g-1) at STP was appreciably enhanced with all mixed-linker SALE products. Using halogenated (-Cl, -Br, and -CF3) imidazole derivatives in a 24 h SALE treatment resulted in increases between 11 and 22% in CO2 adsorption, while the thiol (-SH)- and nitro (-NO2)-functionalized SALE products led to 32 and 100% increases in CO2 uptakes, respectively. These CO2 uptakes were further optimized by varying the SALE treatment time. The SHbIm- and NO2Im-exchanged SALE products of nZIF-8 show 87 and 98 cm3 g-1 of CO2 uptakes after 60 and 120 h of SALE, respectively. These are record high CO2 adsorptions for all reported ZIF derivatives at low-pressure conditions.
| S-EPMC8412924 | biostudies-literature
Project description:The preparation and characterization of composite polybenzimidazole (PBI) membranes containing zeolitic imidazolate framework 8 (ZIF-8) and zeolitic imidazolate framework 67 (ZIF-67) is reported. The phosphoric acid doped composite membranes display proton conductivity values that increase with increasing temperatures, maintaining their conductivity under anhydrous conditions. The addition of ZIF to the polymeric matrix enhances proton transport relative to the values observed for PBI and ZIFs alone. For example, the proton conductivity of PBI@ZIF-8 reaches 3.1 × 10-3 S·cm-1 at 200 °C and higher values were obtained for PBI@ZIF-67 membranes, with proton conductivities of up to 4.1 × 10-2 S·cm-1. Interestingly, a composite membrane containing a 5 wt.% binary mixture of ZIF-8 and ZIF-67 yielded a proton conductivity of 9.2 × 10-2 S·cm-1, showing a synergistic effect on the proton conductivity.
| S-EPMC6215102 | biostudies-literature
Project description:Porous metal-organic frameworks have emerged to resolve important challenges of our modern society, such as CO2 sequestration. Zeolitic imidazolate frameworks (ZIFs) can undergo a glass transition to form ZIF glasses; they combine the liquid handling of classical glasses with the tremendous potential for gas separation applications of ZIFs. Using millimetre-sized ZIF-62 single crystals and centimetre-sized ZIF-62 glass, we demonstrate the scalability and processability of our materials. Further, following the evolution of gas penetration into ZIF crystals and ZIF glasses by infrared microimaging techniques, we determine the diffusion coefficients and changes to the pore architecture on the ångström scale. The evolution of the material on melting and processing is observed in situ on different length scales by using a microscope-coupled heating stage and analysed microstructurally by transmission electron microscopy. Pore collapse during glass processing is further tracked by changes in the volume and density of the glasses. Mass spectrometry was utilized to investigate the crystal-to-glass transition and thermal-processing ability. The controllable tuning of the pore diameter in ZIF glass may enable liquid-processable ZIF glass membranes for challenging gas separations.
| S-EPMC10837076 | biostudies-literature
Project description:Zeolitic imidazolate framework (ZIF) hybrid fluorescent nanoparticles and ZIF antibody conjugates have been synthesized, characterized, and employed in lateral-flow immunoassay (LFIA). The bright fluorescence of the conjugates and the possibility to tailor their mobility gives a huge potential for diagnostic assays. An enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase (HRP) as label, proved the integrity, stability, and dispersibility of the antibody conjugates, LC-MS/MS provided evidence that a covalent link was established between these metal-organic frameworks and lysine residues in IgG antibodies.
| S-EPMC8362128 | biostudies-literature
Project description:B-hive? A family of crystalline materials analogous to porous AlPO(4) but based on boron imidazolate frameworks (BIFs) can be formed by the crosslinking of various presynthesized boron imidazolates with monovalent cations (Li(+) and Cu(+), see picture). This synthetic method is capable of generating a large variety of open frameworks, ranging from the four-connected zeolitic sodalite type to the three-connected chiral (10,3)-a type.
| S-EPMC2790048 | biostudies-literature
Project description:Zeolitic imidazolate frameworks (ZIFs) are very useful as high-capacity iodine (I2) adsorbents. The adsorption performance is usually probed by measuring a statistical average property over an entire sample consisting of a large number of ZIF particles, leaving the interparticle heterogeneity information among individuals. Here we report a dark-field microscopy (DFM) method to visualize gaseous I2 adsorption on single ZIF-90 particles in situ and in real time. The adsorption of I2 is found to alter the scattering spectrum of ZIF-90 particles, inducing a distinct color change from bluewhite to yellow. According to correlating the adsorption amount of gaseous I2 with the change of B value from DFM images, we quantitatively image the adsorption process and estimate the related kinetic parameters at the single particle level. Single particle measurements clarify the large particle-to-particle heterogeneity in adsorption reactivity and significant adsorption activity improvement of ZIF-90 after introduction of linker defects, which provides a microscopic understanding of the structure-activity relationship. We further demonstrate the capacity of this strategy for studying gaseous I2 adsorption on single ZIF-91 particle as a derivative of ZIF-90 to illustrate the generality.
| S-EPMC8302588 | biostudies-literature