A new type of metal−organic framework, [Cd 2 (pdc)(H 2 O)(DMA) 2 ] n (pdc = 3,5-pyrazoledicarboxylic acid; DMA = dimethylamine), named Cd-MOF, was synthesized and characterized. There are regular rectangular pore channels containing a large number of dimethylamine cations in the crystal structure. AC impedance test results show the proton conductivity of Cd-MOF reaches 1.15 × 10 −3 S cm −1 at 363 K and 98% RH. In order for its application in fuel cells, the Cd-MOF was introduced into a sulfonated polyphenylene oxide matrix to prepare a hybrid membrane, and the proton conductivity of the hybrid membrane has a high value of 2.64 × 10 −1 S cm −1 at 343 K and 98% RH, which is higher than those of most MOF polymer hybrid membranes. The proton conductivity of the hybrid membrane of the SPPO polymer still maintains a certain degree of stability in a wide temperature range. To the best of our knowledge, it is the first proton exchange membrane that combines pyrazolecarboxylate cadmium MOFs and an SPPO polymer with high proton conductivity and good stability. This research may help to further develop the application of MOFs in the field of proton exchange membrane fuel cells.
Metal-organic frameworks have great potential in the field of proton conducting materials and fluorescent probes due to their structural tunability and designability. A novel water-stable metal organic framework material [Cd2(Hdpb)(H2O)3]...
The well‐defined 2D or 3D structure of covalent organic frameworks (COFs) makes it have great potential in photoelectric conversion and ions conduction fields. Herein, a new donor–accepter (D–A) COF material, named PyPz‐COF, constructed from electron donor 4,4′,4″,4′″‐(pyrene‐1,3,6,8‐tetrayl)tetraaniline and electron accepter 4,4′‐(pyrazine‐2,5‐diyl)dibenzaldehyde with an ordered and stable π‐conjugated structure is reported. Interestingly, the introduction of pyrazine ring endows the PyPz‐COF a distinct optical, electrochemical, charge‐transfer properties, and also brings plentiful CN groups that enrich the proton by hydrogen bonds to enhance the photocatalysis performance. Thus, PyPz‐COF exhibits a significantly improved photocatalytic hydrogen generation performance up to 7542 µmol g−1 h−1 with Pt as cocatalyst, also in clear contrast to that of PyTp‐COF without pyrazine introduction (1714 µmol g−1 h−1). Moreover, the abundant nitrogen sites of the pyrazine ring and the well‐defined 1D nanochannels enable the as‐prepared COFs to immobilize H3PO4 proton carriers in COFs through hydrogen bond confinement. The resulting material has an impressive proton conduction up to 8.10 × 10−2 S cm−1 at 353 K, 98% RH. This work will inspire the design and synthesis of COF‐based materials with both efficient photocatalysis and proton conduction performance in the future.
Metal-organic frameworks (MOFs), as a porous frame material, exhibit considerable electrical conductivity. In recent decades, research on the proton conductivity of MOFs has made gratifying progress. In this review, the designable guest molecules encapsulated into MOFs are summarized and generalized into four types in terms of promoting proton conductive performance, and then recent progress in the promotion of proton conductivity by MOFs encapsulating guest molecules is discussed. The existing challenges and prospects for the development of this strategy for promoting MOFs' proton conductivity are also listed.
The depletion of traditional fossil energy and the resulting environmental pollution forces people to explore new energy sources. Direct use of solar energy is now a viable solution for solving these problems. Covalent organic frameworks (COFs) are a porous crystalline material; their well-defined two-dimensional or three-dimensional frameworks can ensure the orderly arrangement of photoelectric active units, giving them potential photoelectric conversion applications. The tunable structural features endow COFs many advantages in photocatalytic hydrogen production under visible light. This review comprehensively summarizes the research progress on photoelectronic donor–acceptor (D-A) COFs with tunable structure for photocatalytic hydrogen evolution and will provide a feasible guiding strategy for applying this type of COFs in photocatalytic hydrogen production.
A new quaternary crystalline catalyst was obtained by a mixed hydrothermal method of integrating inorganic semiconductors, titanium oxide cluster (TOC) and molecular redox centers orderly into metal organic framework (MOF) materials. It shows a hydrogen production rate 3711.53 μmol g À 1 h À 1 under visible light irradiation, exceeds most of the same type of catalyst reported in recent years, and a favorable stability with. The excellent performance of the CdS/TOC/UiO-67-bpy/Co composites due to efficient promotion of photo-induced carrier separation and migration, and offering abundant active sites for generating hydrogen. This work will help to guide the preparation of new efficient and stable photocatalysts and promote the effective conversion of solar energy to chemical energy.
In order to study the influence of different solvent molecules on the proton conductivity of MOF, {[Zn(pyeb)2](DMF)(H2O)}n (1) (PyebH=4-[2-(4-pyridyl)vinyl)]-benzoic acid, DMF denotes N,N′-dimethylformamide) was selected and synthesized due to different...
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