Search

The preparation of single crystals, especially large-size ones, is highly important but challenging. Herein, exploiting the special nucleation and growth environment provided by the Marangoni effect, we synthesised oriented centimetre-sized Zn-MOF crystals. These large-size single crystals can be employed for separation of mixed-ionic dyes without any further processing. This work opens up a brand-new avenue for the synthesis of large-size single-crystals. [ABSTRACT FROM AUTHOR]

Epitaxial metal–organic framework (MOF) films have shown huge potential for use in separation applications. Herein, bendable epitaxial MOF films are fabricated via spraying. The synthesized MOF films show excellent oil-in-water emulsion separation performance even after being bent for multiple times at high curvatures. [ABSTRACT FROM AUTHOR]

Redox‐active metal–organic frameworks (MOFs), with switchable physicochemical properties depending on their redox state, are widely used in catalysis, selective separation, and electrochemical sensing. However, the complex fabrication process limits the applications. Herein, a post‐synthetic modification strategy is proposed to prepare redox‐active MOFs by covalent grafting organic selenium compounds. The selenium moieties can reduce metal salt to in situ generate metal nanoparticles (MNPs) without an external reducing agent, and also act as anchors to stabilize the generated MNPs. As a proof of concept, two kinds of MOFs are selected to prepare redox‐active MOFs‐Se and further fabricate MNPs@MOFs composite materials. With controllable confinement of the MNPs, the MNPs@MOFs composite show noteworthy photocatalytic and electrocatalytic activity. [ABSTRACT FROM AUTHOR]

A mesoporous silica bearing uniformly distributed copper oxide nanoparticles (CuO@mesoporous SiO2) was prepared through silica nanocasting copper metal organic frameworks (MOFs) followed by calcination. The nanocasting filled the micropores of MOFs with silica and then, the calcination removed the organic linker in MOFs and converted copper metal ions into CuO particles, resulting in the CuO@mesoporous SiO2 architecture. The characterization results indicated that the final product basically maintained the original MOF morphology and the mesoporous silica effectively prevented the aggregation of nanoparticles. In addition, the CuO@mesoporous SiO2 exhibited a superior activity for catalyzing the oxidation of styrene, which could be attributed to the fact that the dispersed CuO particles in mesoporous silica provided more accessible catalytic sites and better stability. This work provides a new strategy to prepare nanoparticles@mesoporous silica with adjustable morphology structure, which has a promising potential in the field of heterogeneous catalysis. Nanocasting SiO2 into metal organic frameworks (MOF) provides adequate protection for the pyrolysis of MOF into CuO nanoparticles and prevents their aggregation. The prepared CuO@SiO2 exhibited outstanding catalytic performance and excellent recyclability in the styrene oxidation reaction owing to the abundant active sites and the good stability brought by the SiO2 skeleton. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) as templates can easily form homogeneous multimetallic materials via metal ion exchange, and they have been widely used as electrocatalysts in the oxygen evolution reaction (OER) due to the synergistic effect of the metal ions. Herein, by selecting Cu(BDC) as a template, a simple one-step impregnation method was used to prepare CuCoNi trimetallic electrocatalysts, which exhibited excellent catalytic performance for the OER with a low overpotential of 327 mV at a 10 mA cm−2 current density and a small Tafel slope of 75.7 mV dec−1. The outstanding OER activity may be attributed to the transformed 2D lamellar morphology, amorphous structure and the synergistic effect of the metal species. [ABSTRACT FROM AUTHOR]

A feasible and rapid one-step strategy has been developed to fabricate 2D metal–organic framework nanosheet (MOF-NS)@fiber composites at room temperature by spray technique, through which five kinds of MOF-NS@fiber were successfully prepared. The representative nanoscale CuBDC were synthesized on the surface of carbon fibers with homogeneous dispersion and high coverage. [ABSTRACT FROM AUTHOR]

Pore size enlargement plays a vital role in the catalytic applications of metal-organic frameworks (MOFs). There is still a big challenge in achieving two-dimension (2D) ultrathin MOF nanosheets with controllable meso-pores, although it has huge demanding. In this work, various kinds of mesoporous MOF nanosheets with uniform meso-pore channels and crystallized microporous frameworks were constructed using surfactants (cetyltrimethyl ammonium bromide, CTAB) as sacrificial templates. CTAB was firstly introduced into MOF nanosheet structure during the formation of MOF nanosheets, and mesopores could be produced by removing CTAB from MOF nanosheets. Remarkably, the integration of ultrathin nanosheets and mesoporous property enables mesoporous CuBDC nanosheets enhanced catalytic activity for C–S cross-coupling reaction, providing a new concept and feasible strategy for highly efficient mesoporous MOF catalyst synthesis. Image 1 • Synthesis of mesoporous two-dimension metal-organic frameworks nanosheets. • High performance in C–S cross-coupling reaction. • Kinetic study of catalytic reaction. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) hybrids are novel porous composite materials with potential applications in advanced membrane separations. However, the preparation of defect-free and self-standing separation membranes remains challenging. Here, we report a COF-MOF composite membrane with a sandwich layer structure and a two-dimensional (2D) intergrown nanosheet morphology. This was achieved by inducing the secondary growth of a layer of MOF (ZIF-67) membrane using a two-dimensional COF (TpPa1) membrane as a seed layer and porous support. It is worth noting that a rare ZIF-67 membrane consisting of 2D nanosheets was grown on the TpPa1 porous support. The [TpPa1]-[ZIF-67] membranes exhibited excellent permeance for organic solvents, pure water (95.3 L m−2 h−1 bar−1), with high rejection rates (>97 %) towards dyes larger than 700 Da, while maintaining a low rejection rate for hydrated salt ions (<14 %) and outstanding dye/salt selectivity. The membranes also displayed considerable long-term operational stability and could be easily transferred to other substrates without damaging their integrity. The excellent separation properties achieved through layer-by-layer filtration are mainly due to the sandwich structure and the synergistic effect of the components. Preparation of self-standing [TpPa1]-[ZIF-67] composite membranes with a sandwich layer structure and a two-dimensional intergrown nanosheet morphology. The [TpPa1]-[ZIF-67] membranes provide high flux for organic solvents, pure water, low rejection of salt ions and high rejection of dyes with long term operational stability. [Display omitted] • Preparation of self-standing COF-MOF membranes with a sandwich layer structure and a 2D intergrown nanosheet morphology. • A rare two-dimensional nanosheet of ZIF-67 was grown on the TpPa1 porous support. • The [TpPa1]-[ZIF-67] membranes provide high flux high rejection of dyes, and long term operational stability. • The separation performance are primarily attributed to the synergistic effect of each component of the sandwich structure. [ABSTRACT FROM AUTHOR]

The Cu-based metal–organic framework (MOF) analogues, copper 1,4-benzenedicarboxylate (CuBDC), copper 2,6-naphthalenedicarboxylate (Cu(2,6-NDC)), and copper 1,4-naphthalenedicarboxylate (Cu(1,4-NDC)) MOF nanosheets, are prepared as biosensor nanoplatforms for DNA detection by a spray method. With the ultrathin 2D structure, the fabricated MOF nanosheets exhibited better detection of target DNA, in particular when compared with the corresponding 3D MOF bulky crystals, when used as a DNA biosensor platform. The Cu(1,4-NDC) nanosheets display a distinct sensitivity with a detection limit of 0.3 nM and linear range of 0–20 nM, and selectivity for the target DNA or target DNA mixture. The feasible biosensor nanoplatform composed of 2D MOF nanosheets broadens the application scope of MOF nanosheets. Cu-based 2D MOF nanosheets are fabricated as sensing nanoplatforms for DNA detection. The representative Cu(1,4-NDC) nanosheets provide good sensitivity and selectivity towards target DNA (T1 and T2) or a target DNA mixture in the presence with dye-labelled probe DNA (P1 and P2), which is evaluated by fluorescence intensity. [ABSTRACT FROM AUTHOR]

[Display omitted] • This work directly fabricating 2D MOFs with good colloidal stability. • Based on coordination modulation to improve the colloidal stability of 2D MOFs. • Modulator with methoxy group can speculatively modify MOF surface. • The original morphology and porous crystal structure of 2D MOFs was remained. • The well-dispersed 2D MOFs shows excellent catalytic performance. Two-dimensional metal–organic frameworks (MOFs) have emerged as an attractive type of 2D materials, especially in surface-dependent reactions. And the colloidal stability of 2D MOF is crucial to its performance in surface-dependent application. This work provides a facile approach for directly fabricating 2D MOF with good colloidal stability by introducing monotopic ligand as modulator through coordination modulation. Modulator with methoxy group can effectively decrease the size of 2D MOF nanosheet and selectively modify MOF surface to improve its colloidal stability without changing its nanosheet morphology and porous crystal structure. The well-dispersed 2D MOFs provide more active specific surface area, which shows excellent catalytic performance in the synthesis of Schiff base. This method paves a new way to fabricate MOF-based materials with remarkable performances for surface-dependent application. [ABSTRACT FROM AUTHOR]

Two-dimensional metal-organic frameworks (2D MOFs) have presented application potential in various fields, and their size and morphology are vital to their practical application. And coordination modulation has been proved as an effective strategy to adjust MOF structure to enhance its performance by modulating MOF crystal growth. Herein, a facile method is presented to control the size and morphology of 2D MOF, CuBDC (BDC is 1,4-benzenedicarboxylic), through coordination modulation. With increased modulator 4- n -butylbenzoic acid (NBA) addition, the morphological transformation from nanosheet to nanoflower then to sheet, and the size transformation from smaller nanosheet to larger sheet are achieved by the kinetic trapping of crystal growth at room temperature. Such kinetic trapping products show different size and morphology with intact crystal structure of original CuBDC and low NBA content. Among them, nanoflower products show higher catalytic efficiency and better stability for the catalytic synthesis of benzylidene aniline relative to other products and CuBDC. [Display omitted] • Coordination modulation of two-dimensional metal-organic framework. • The morphology of products from nanosheet to nanoflower then to sheet. • The size of products from smaller nanosheet to larger sheet. • The transformation of products achieved by the kinetic trapping of crystal growth. • The nanoflower product shows higher catalytic efficiency of benzylidene aniline. [ABSTRACT FROM AUTHOR]

[Display omitted] • Post-synthetic modification of two-dimensional metal-organic framework. • CuBDC-NH 2 nanosheet reacts with isocyanate-terminated polyurethane oligomer(PU). • The CuBDC-NH 2 /PU is conducted to prepare functional nanocomposite membrane. • The CuBDC-NH 2 /PU membrane shows over 93.0 % removal rate for dye removal. Two-dimensional metal-organic framework (2D MOF) nanosheet is becoming as an attractive type of 2D materials. And Post-synthetic modification (PSM) provides a powerful method to modify the structure of MOF without altering its crystal topology, which can generate functional MOFs not accessible from direct synthesis and improve the compatibility between MOFs and other components in MOF-based composite materials, especially in MOF/polymer composite. In this work, a facile method based on PSM of 2D MOF with polymers is conducted to prepare functional nanocomposite membrane. First, the amino-functioned 2D MOF nanosheet, CuBDC-NH 2 (BDC-NH 2 is 2-amino-1,4-benzenedicarboxylate), has been prepared as PSM precursor. Then CuBDC-NH 2 nanosheet reacts with isocyanate-terminated polyurethane (PU) oligomer through PSM to obtain CuBDC-NH 2 /PU nanocomposite membrane, which show over 93.0 % removal rate for dye removal, such as methylene blue, Rhodamine B and Eosin Y. [ABSTRACT FROM AUTHOR]