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Simultaneous laser-induced synthesis and micro-patterning of a metal organic framework
摘要： Micro-patterning of a metal organic framework (MOF) from a solution of precursors is achieved by local laser heating. Nano-sized MOFs are formed, followed by rapid assembly due to convective flows around a heat-induced micro-bubble. This laser-induced bottom-up technique is the first to suggest simultaneous synthesis and micro-patterning of MOFs, alleviating the need for pre-preparation and stabilization.
关键词： laser-induced synthesis,metal organic framework,Marangoni convection flows,micro-patterning,nano-MOFs
更新于2025-09-12 10:27:22
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Investigating Adsorption/Desorption of DNA on ZIF-8 Surface by Fluorescently Labeled Oligonucleotides
摘要： As an important subclass of MOFs, ZIF-8, built from 2-methylimidazole and Zn(NO3)2 · 6H2O, possesses the excellent biocompatibility and high stability in aqueous solution. Recently, it has been found that ZIF-8 can efficiently adsorb DNA, and quench the adsorbed fluorophores to a large extent. These properties make it possible to prepare DNA-based optical sensors using ZIF-8. Although practical analytical applications are being demonstrated, the basic understanding of the binding between ZIF-8 and DNA in solution has received relatively little attention. In this work, we report that the adsorption of 12-, 18-, 24-, and 36-mer single-stranded DNAs on ZIF-8 are affected by several factors. It is found from the outcomes that shorter DNAs are adsorbed more rapidly to the surface of ZIF-8. On the other hand, desorption of the probe DNA can be achieved using complementary strand DNA to restore the fluorescence value. Furthermore, the salt contributes to adsorption to some extent. These findings are important for further understanding of the interactions between DNA and ZIF-8 and for the optimization of DNA and MOF-based devices and sensors.
关键词： fluorescent DNA probe,MOFs,optical sensors,ZIF-8
更新于2025-09-12 10:27:22
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Self‐Assembly of Hybrid Oxidant POM@Cu‐BTC for Enhanced Efficiency and Long‐Term Stability of Perovskite Solar Cells
摘要： The controllable oxidation of spiro-OMeTAD and improving the stability of hole-transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid framework material, (POM@MOF) [Cu2(BTC)4/3(H2O)2]6[H3PMo12O40]2 or POM@Cu-BTC, for the oxidation of spiro-OMeTAD with Li-TFSI and TBP. When POM@Cu-BTC is introduced to the HTM layer as a dopant, the PSCs achieve a superior fill factor of 0.80 and enhanced power conversion efficiency 21.44 %, as well as improved long-term stability in an ambient atmosphere without encapsulation. The enhanced performance is attributed to the oxidation activity of this POM anions and solid-state nanoparticles. Therefore, research presents a facile way by using hybrid porous materials to accelerate oxidation of spiro-OMeTAD, further improving the efficiency and stability of PSCs.
关键词： hole-transport materials,metal–organic frameworks (MOFs),polyoxometalates,perovskites,solar cells
更新于2025-09-11 14:15:04
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Metal-organic Frameworks Derived Porous Cake-like TiO2 as an Efficient Scattering Layer for Dye-Sensitized Solar Cells
摘要： Porous anatase cake-like TiO2 was prepared by annealing Ti-based metal-organic frameworks (MOFs) MIL-125, which was then used as an efficient scattering layer in dye-sensitized solar cells (DSSCs). The morphology and structure of the prepared porous cake-like TiO2 were characterized by SEM, TEM, and XRD. DSSCs with porous cake-like TiO2 as an efficient scattering layer exhibited a photoelectric conversion efficiency (PCE) of 6.91%, which was greater than that of single P25 TiO2 based DSSCs (3.89%). The improved photoelectric conversion efficiency was attributed to the crucial role of porous cake-like TiO2 in promoting surface area and incident light scattering performance, as demonstrated by N2 adsorption/desorption isotherm analysis, diffuse reflectance spectroscopy, incident photon-to-current efficiency (IPCE) analysis, and electrochemical impedance spectroscopy (EIS).
关键词： MOFs,DSSCs,Porous cake-like TiO2,Light scattering layer
更新于2025-09-11 14:15:04
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Zn-Free MOFs like MIL-53(Al) and MIL-125(Ti) for the preparation of defect-rich, ultrafine ZnO nanosheets with high photocatalytic performance
摘要： Metal organic frameworks (MOFs) are exploited in many applications of materials science and very recently were investigated as precursors or reagents for material synthesis. In a new way different from previous approaches, here we introduce for the first time the synthesis of metal oxide MxOy in the presence of M-free MOF acting partially as a sacrificial template and as a provider of doping metal atom. We demonstrate this approach in the case of ZnO prepared by a simple hydrothermal method in the presence of a Zn-free MOF like MIL-53(Al) or MIL-125(Ti). The resulting ZnO show low content of Al or Ti < 2% and properties are significantly different depending on whether MIL-53(Al) or MIL-125(Ti) are used or if no MOF is present. The nature and presence of MOF has different major effects on the morphology, the specific surface area of as prepared ZnO and also on the oxygen defects in its crystal structure. Corroborating the XPS, UV-Vis DRS, PL, EPR and DFT studies evidence the role of such O-defects on band gap narrowing for samples calcined at 400°C. These exhibit high efficiency in photodegradation of methyl orange (MO) compared to ZnO prepared in MOF-free conditions or previous literatures. The kinetics of MO degradation is different depending on the morphology, the specific surface and oxygen defects. The present data open the door to a new approach of the synthesis of metal oxides and a control of their properties
关键词： Oxygen defects,Zinc oxide,MOFs,Template,Photocatalysis
更新于2025-09-10 09:29:36
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Photoreduction of Carbon Dioxide to Methanol over Copper Based Zeolitic Imidazolate Framework-8: A New Generation Photocatalyst
摘要： The efficient reduction of CO2 into valuable products such as methanol, over metal-organic frameworks (MOFs) based catalyst, has received much attention. The photocatalytic reduction is considered the most economical method due to the utilization of solar energy. In this study, Copper (II)/Zeolitic Imidazolate Framework-8 (Cu/ZIF-8) catalysts were synthesized via a hydrothermal method for photocatalytic reduction of CO2 to methanol. The synthesized catalysts were characterized by X-ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray (EDX), Ultraviolet-visible (UV-vis) spectroscopy, and X-Ray Diffraction (XRD). The host ZIF-8, treated with 2 mmol copper prepared in 2M ammonium hydroxide solution showed the highest photocatalytic activity. The crystal structures of ZIF-8 and 2Cu/ZIF-8N2 catalysts were observed as cubic and orthorhombic, respectively and the XPS analysis confirmed the deposition of Cu (II) ions over ZIF-8 surface among all the prepared catalysts. The orthorhombic structure, nano-sized crystals, morphology and Cu loading of the 2Cu/ZIF-8N2 catalyst were the core factors to influence the photocatalytic activity. The yield of Methanol was found to be 35.82 μmol/L·g after 6 h of irradiations on 2Cu/ZIF-8N2 catalyst in the wavelength range between 530–580 nm. The copper-based ZIF-8 catalyst has proven as an alternative approach for the economical photocatalytic reduction of CO2 to CH3OH.
关键词： Cu/ZIF-8,photocatalytic CO2 reduction,methanol production,metal-organic frameworks (MOFs)
更新于2025-09-10 09:29:36
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Fabrication of Novel ZIF-8@BiVO4 Composite with Enhanced Photocatalytic Performance
摘要： In this work, a novel metal-organic framework (MOF) and BiVO4 (BVO) composite photocatalyst was successfully synthesized by an in-situ growth method. The characterization of obtained samples was done by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, N2 adsorption, and photoluminescence spectroscopy. The photocatalytic performance of ZIF-8@BiVO4 composite was evaluated by the degradation of methylene blue (MB) under simulated visible light irradiation. Compared with the mixture of BVO and ZIF-8, the composite photocatalyst exhibited superior photodegradation ef?ciency, which could be attributed to the synergistic effect between BVO and ZIF-8. The reduced recombination of photogenerated electrons and holes was considered to be an important reason for the enhancement of photocatalytic performance. This design demonstrates a rational method to improve the photocatalytic performance by combining photocatalysts with MOFs.
关键词： photocatalyst,BiVO4,MOFs,visible light
更新于2025-09-09 09:28:46
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MOFs-derived ultrathin holey Co3O4 nanosheets for enhanced visible light CO2 reduction
摘要： Reducing carbon dioxide (CO2) to various value-added chemical products by photocatalysis could effectively alleviate the serious problems of global warming and energy shortages. Currently, most commonly prepared photocatalysts present poor performance under visible light irradiation. In this study, we adopted a facile, scalable and controllable approach to prepare ultrathin two-dimensional (2D) porous Co3O4 catalysts (Co3O4-NS) by air calcining of the ultrathin metal-organic framework (MOFs) nanosheet templates to validly reduce CO2 with a Ru-based photosensitizer under visible light irradiation. Benefitting from the structural nature of MOFs precursors, the calcined Co3O4-NS inherit the morphology of 2D and well-developed porosity, which support the transport of electrons, enhance the adsorption of CO2 molecules, and render abundant catalytic sites for CO2 activation. As a result, the CO generation rate is approximately 4.52 μmol·h-1 with selectivity of 70.1%, which is superior to the Co3O4 bulk catalysts (Co3O4-BK). Additionally, density functional theory (DFT) calculations reveal that the model of Co3O4 monolayer has stronger CO2 adsorption energy than that of the Co3O4 bulk, which is beneficial for the CO2-to-CO conversion. This MOF-engaged strategy provides new insight into the controlled synthesis of advanced ultrathin holey nanosheets to improve the efficiency of photocatalytic CO2 reduction.
关键词： ultrathin nanosheets,Co3O4,photocatalysis,MOFs derived,CO2 reduction
更新于2025-09-04 15:30:14
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Noble metal nanoparticle-functionalized Zr-metal organic frameworks with excellent photocatalytic performance
摘要： Noble metal nanoparticles (NPs) functionalized MOFs are attractive materials for photocatalytic reactions, and outstanding catalytic performances can be expected, especially when they have intrinsically matched crystal faces between metals and MOFs. This study discovered that the photocatalytic oxidation of aromatic alcohols to aldehydes was enhanced over Au/UiO-66-NH2 or Au/UiO-66 but suppressed over Pt loaded counterparts, whereas the reduction of Cr(VI) was boosted over both two catalysts. In reactions, the conversion of benzyl alcohol was 17.1% over UiO-66-NH2 and 7.6% over UiO-66, and an enhanced conversion was obtained over Au/UiO-66-NH2 (30.5%) and Au/UiO-66 (24.1%). However, the conversion was decreased over Pt/UiO-66-NH2 (9.3%) and Pt/UiO-66 (<1%). Experimental results revealed strong correlations between Zr-MOFs and loaded metal NPs, as Zr centers promoted the formation of Pt(200) planes that suppressed the production of (cid:1)O2 intermediates to oxidize aromatic alcohols, whereas Pt(200) exhibited no effect on the Cr(VI) reduction triggered by photo-induced electrons. The findings in this study on constructing noble metal NPs functionalized Zr-MOFs catalysts with specially-matched crystal structures and on distinguishing photocatalytic mechanisms on oxidation of alcohols and reduction of Cr(VI) would provide valuable information for designer (photo)catalysts based on MOFs and their applications in such as catalysis and environmental remediation.
关键词： Photocatalysis,Zr-MOFs,Metal loading,Pt(200) plane
更新于2025-09-04 15:30:14
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Four new luminescent-organic frameworks exhibiting highly sensing of nitroaromatics: an experimental and computational insight
摘要： Four new metal–organic frameworks (MOFs) namely {[Cd(L)(bpp)]·H2O}n (1), {[Zn(L)(bpp)]·H2O}n (2), {[Cd(L)(bpz)]·H2O}n (3), [Zn(L)(bib)(H2O)]n (4), (H2L = 1,4-bis(4-carboxylbenzyl)piperazine acid; bpp =1,3-bis(4-pyridyl)propane; bpz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole, bib = 1,4-bis(imidazol-1-yl)butane)) have been designed, synthesized and characterized. The MOFs 1 and 2 are isostructural and possess 4-connected dia topology with rare 8-fold interpenetrating network. In 3, the dianionic ligand L and bpz ligands link binuclear Cd(II) centres to generate a 2D layer framework with a double stranded chain. While in 4, the Zn(II) centres are bridged by L and bib ligands to furnish a 2D framework, which further generates a 3D supramolecular structure through the hydrogen bonding interactions formed between coordinated water molecules and carboxylate groups. The MOF 1 have been utilized as a possible luminescent sensor to detect nitroaromatic compounds (NACs). The results indicates that 1 showed good sensitivity towards p-nitrophenol (PNP) in comparison to other NACs by the decline in its luminescent intensity. The detection limit for PNP was found to be extremely low(1.27 ppm in solution) which represents one of the most efficient MOF-based sensors for PNP. The most plausible mechanism associated with sensing have been explained with the aid of theoretical calculations which indicated that a simultaneous electron/energy transfer phenomenon operating between 1 and NACs contributes toward the decline in the luminescence intensity
关键词： Nitroaromatic,Luminescence sensor,MOFs,Theoretical calculation
更新于2025-09-04 15:30:14