Photocatalytic Hydrogen Production Coupled with Selective Benzylamine Oxidation over MOF Composites.

Photocatalytic water splitting requires separation of the mixed H2 and O2 products and is often hampered by the sluggish O2‐producing half reaction. An approach is now reported to address these issues by coupling the H2‐producing half reaction with value‐added benzylamine oxidation reaction using metal–organic framework (MOF) composites. Upon MOF photoexcitation, the electrons rapidly reduce the protons to generate H2 and the holes promote considerable benzylamine oxidation to N‐benzylbenzaldimine with high selectivity. Further experimental characterizations and theoretical calculation reveal that the highly conjugated s‐triazine strut in the MOF structure is crucial to the efficient charge separation and excellent photocatalytic activity.

An "on-off-on"-type electrochemiluminescence (ECL) aptamer sensor based on Ru@Zn-oxalate metal-organic framework (MOF) composites is constructed for sensitive detection of sulfadimethoxine (SDM). The prepared Ru@Zn-oxalate MOF composites with the three-dimensional structure provide good ECL performance for the "signal-on." The MOF structure with a large surface area enables the material to fix more Ru(bpy)32+. Moreover, the Zn-oxalate MOF with three-dimensional chromophore connectivity provides a medium which can accelerate excited-state energy transfer migration among Ru(bpy)32+ units, and greatly reduces the influence of solvent on chromophore, achieving a high-energy Ru emission efficiency. The aptamer chain modified with ferrocene at the end can hybridize with the capture chain DNA1 fixed on the surface of the modified electrode through base complementary pairing, which can significantly quench the ECL signal of Ru@Zn-oxalate MOF. SDM specifically binds to its aptamer to separate ferrocene from the electrode surface, resulting in a "signal-on" ECL signal. Theuse of the aptamer chain further improves the selectivity of the sensor. Thus, high-sensitivity detection of SDM specificity is realized through the specific affinity between SDM and its aptamer. This proposed ECL aptamer sensor has good analytical performance for SDM with low detection limit (27.3 fM) and widedetection range (100 fM-500nM). The sensor also shows excellent stability, selectivity, and reproducibility, which proved its analytical performance. Therelative standard deviation (RSD) of SDM detected by the sensor is between 2.39 and 5.32%, and the recovery is in the range 97.23 to 107.5%. The sensor shows satisfactory results in the analysis of actual seawater samples, which is expected to play a role in the explorationof marine environmental pollution.

The exploitation of photocatalysts that harvest solar spectrum as broad as possible remains a high-priority target yet grand challenge. In this work, for the first time, metal-organic framework (MOF) composites are rationally fabricated to achieve broadband spectral response from UV to near-infrared (NIR) region. In the core-shell structured upconversion nanoparticles (UCNPs)-Pt@MOF/Au composites, the MOF is responsive to UV and a bit visible light, the plasmonic Au nanoparticles (NPs) accept visible light, whereas the UCNPs absorb NIR light to emit UV and visible light that are harvested by the MOF and Au once again. Moreover, the MOF not only facilitates the generation of "bare and clean" Au NPs on its surface and realizes the spatial separation for the Au and Pt NPs, but also provides necessary access for catalytic substrates/products to Pt active sites. As a result, the optimized composite exhibits excellent photocatalytic hydrogen production activity (280 µmol g-1 h-1 ) under simulated solar light, and the involved mechanism of photocatalytic H2 production under UV, visible, and NIR irradiation is elucidated. Reportedly, this is an extremely rare study on photocatalytic H2 production by light harvesting in all UV, visible, and NIR regions.

Metal organic framework composites as adsorbents: Synergistic effect for water purification

Composites of metal-organic frameworks (MOFs) and LDHs for energy storage and environmental applications: Fundamentals, progress, and perspectives

Magnetic metal-organic frameworks nanocomposites for negligible-depletion solid-phase extraction of freely dissolved polyaromatic hydrocarbons

Organic ligands critically determine the composition and structure of metal-organic frameworks (MOFs). While iron-based MOFs have been studied as controlled-release fertilizers (CRFs), the influence of dual organic ligands on their structural and functional properties in agriculture remains poorly understood. In this study, three iron-based MOFs were synthesized: MOF1 (oxalic acid ligand), MOF2 (tartaric acid ligand), and MOF3 (1:1 dual-ligand mixture). Despite comparable nitrogen and iron contents, MOF1 and MOF2 formed uniform microcrystals, whereas MOF3 exhibited irregular, larger crystallites due to oxalic acid's dominant coordination, driven by its stronger coordination affinity relative to tartaric acid. Nutrient release studies revealed that MOF3 exhibited the fastest release kinetics, followed by MOF1 and MOF2, which were well-described by the Higuchi and Ritger-Peppas models. Soil simulation trials demonstrated that all MOFs significantly improved the fertility of saline-alkali soils, reducing pH (by 1.52 units) and salinity (by 6.75%), with MOF3 demonstrating the greatest efficacy. Pot and field trials further confirmed MOF3's superiority through promoting bok choy and maize growth in paddy soil, and increasing maize yield by 42.6% in saline-alkali soil. These results highlight the potential of dual-ligand MOFs as efficient CRFs and soil conditioners for sustainable agriculture.

Probing the capability of the MOF-74(Ni)@GrO composite for CO2 adsorption and CO2/N2 separation: A combination of experimental and molecular dynamic simulation studies

Recent development in metal-organic framework-based hybrid nanocomposites for pollutants remediation from wastewater: Challenges and opportunities

Metal-organic framework (MOF) composites as promising materials for energy storage applications

CO2 separation from flue gas mixture using [BMIM][BF4]/MOF composites: Linking high-throughput computational screening with experiments

Potential applications of MOF composites as selective membranes for separation of gases

One-pot electrodeposition of metal organic frameworks composites accelerated by electroreduced graphene oxide and gold nanoparticles for rutin electroanalysis

Metal–organic frameworks (MOFs) also known as porous coordination polymers (PCP) are crystalline compounds including metal ion or cluster of metal ions coordinated to organic linkers. To provide more functionalities and enhance the MOFs properties, design and construction of MOFs composites have been proposed. MOF composites are materials that consist of combination of nanoparticles and MOFs. In this chapter, first a brief review of MOF materials and their synthesis approaches is presented. Then, MOF composites and their synthesis methods and applications are reviewed. Finally, the latest applications of advanced atomic force microscopy techniques to study the crystallization, morphology and structures of MOFs and their composites with nanomechanical characterization are reviewed.

Photocatalytic degradation is an energy efficient, cost-effective, and stable process that has a wide-range of application. It is considered as a promising method for the removal of organic pollutants. As a new type of porous material, Metal-organic framework (MOF) composites have been proven to be an ideal catalyst for the degradation of organic pollutants due to their small size and large specific surface area. In this review, several common preparation methods of MOF composites are evaluated: microwave synthesis, solvent-thermal method, electrochemical method and layer by layer growth method. The degradation effects of MOF composites on different organic pollutants are summarized, and the excellent photocatalytic performances of some MOF composites are demonstrated. Finally, the prospects of photocatalytic degradation of organic pollutants by MOF composites are examined, and the challenges in further development of MOF composites are discussed.