Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nano...Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance.展开更多
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under...(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.展开更多
Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded...Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded organic frameworks(HOFs)have promising application potential for embedding enzymes.In fact,no metal involvement is required,and HOFs exhibit superior biocompatibility,and free access to substrates in mesoporous channels.Herein,a facile in situ growth approach was proposed for the self-assembly of alcohol dehydrogenase encapsulated in HOF.The micron-scale bio-catalytic composite was rapidly synthesized under mild conditions(aqueous phase and ambient temperature)with a controllable embedding rate.The high crystallinity and periodic arrangement channels of HOF were preserved at a high enzyme encapsulation efficiency of 59%.This bio-composite improved the tolerance of the enzyme to the acid-base environment and retained 81%of its initial activity after five cycles of batch hydrogenation involving NADH coenzyme.Based on this controllably synthesized bio-catalytic material and a common lipase,we further developed a two-stage cascade microchemical system and achieved the continuous production of chiral hydroxybutyric acid(R-3-HBA).展开更多
Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreo...Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreover,due to the accumulation of COFs nanoparticles,it is not conducive to the full utilization of their surface functional groups.Currently,the strategy of COFs assembling into aerogel can be a good solution to this problem.Herein,we successfully synthesize composite aerogels(CSR)by in-situ self-assembly of two-dimensional COFs and graphene based on crosslinking of sodium alginate.Sodium alginate in the composite improves the mechanical properties of the aerogel,and graphene provides a template for the in-situ growth of COFs.Impressively,CSR aerogels with different COFs and sizes can be prepared by changing the moiety of the ligand and modulating the addition amount of COFs.The prepared CSR aerogels exhibit porous,low density,good processability and good mechanical properties.Among them,the density of CSR-N-1.6 is only 5 mg/cm3,which is the lowest density among the reported COF aerogels so far.Due to these remarkable properties,CSR aerogels perform excellent adsorption and recycling properties for the efficient and rapid removal of organic pollutants(organic dyes and antibiotics)from polluted water.In addition,it is also possible to visually recognize the presence of antibiotics by fluorescence detection.This work not only provides a new strategy for synthesizing COF aerogels,but also accelerates the practical application of COF aerogels and contributes to environmental remediation.展开更多
Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent y...Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent yet remain challenge to achieve.Herein,we propose a robust,universal and efficient fluorescence-based strategy for hierarchical warning of coating damage and metal corrosion by introducing the concepts of damage-induced fluorescence enhancement effect(DIE)and ionic-recognition induced quenching effect(RIQ).The coatings with dualresponsiveness for coating defect and steel corrosion are constructed by incorporating synthesized nanoprobes composed of metal organic frameworks(Ni–Zn-MOFs)loaded with Rhodamine B(RhB@MOFs).The initial damage to the coating causes an immediate intensification of fluorescence,while the specific ionic-recognition characteristic of RhB with Fe3t results in an evident fluorescence quenching,enabling the detection of coating damage and corrosion.Importantly,this nanoprobes are insensitive to the coating matrix and exhibit stable corrosion warning capability across various coating systems.Meanwhile,electrochemical investigations indicate that the impedance values of RM/EP maintain above 10^(8)Ωcm^(2)even after 60 days of immersion.Therefore,the incorporation of fluorescent nanoprobes greatly inhibits the intrusion of electrolytes into polymer and improves the corrosion protection performance of the coating.This powerful strategy towards dual-level damage warning provides insights for the development of long-term smart protective materials.展开更多
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ...A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.展开更多
Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomer...Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomers(p-phenylenediamine(Pa),benzidine(BD),and 4,4"-diamino-p-terphenyl(DATP))were used to synthesize a series of two-dimensional covalent-organic frameworks(COFs).The resulting COFs were named TpPa,TpBD,and TpDATP,respectively,and they showed uniform zincophilic sites,different pore sizes,and high Young's moduli on the Zn anode.Among them,TpPa and TpBD showed lower surface work functions and higher ion transfer numbers,which were conducive to uniform galvanizing/stripping zinc and inhibited dendrite growth.Theoretical calculations showed that TpPa and TpBD had wider negative potential region and greater adsorption capacity for Zn2+than TpDATP,providing more electron donor sites to coordinate with Zn^(2+).Symmetric cells protected by TpPa and TpBD stably cycled for more than 2300 h,whereas TpDATP@Zn and the bare zinc symmetric cells failed after around 150 and200 h.The full cells containing TpPa and TpBD modification layers also showed excellent cycling capacity at 1 A/g.This study provides comprehensive insights into the construction of highly reversible Zn anodes via COF modification layers for advanced rechargeable ZIBs.展开更多
Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high po...Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other gases.This review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO_(2)capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit interactions.Besides,the main challenges associated with porous frameworks for CO_(2)capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and emphasized.This review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.展开更多
The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Cova...The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.展开更多
The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNT...The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNTs)during the growth process of MOF crystals,synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure.Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin.Simultaneously,the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency.X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co,optimizing the electronic structure.Consequently,the E_(1/2) of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V(vs.RHE),outperforming the catalyst without CNTs.When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells(MFCs)with Nafion-117 as the proton exchange membrane,the maxi-mum power density of MFCs reached approximately 500 mW·m^(-2).展开更多
Photocatalytic CO_(2)cycloaddition reaction presents a promising CO_(2)conversion strategy to establish carbon neutrality.Among emerging catalysts,metal‑organic frameworks(MOFs)have been regarded as paradigmshifting p...Photocatalytic CO_(2)cycloaddition reaction presents a promising CO_(2)conversion strategy to establish carbon neutrality.Among emerging catalysts,metal‑organic frameworks(MOFs)have been regarded as paradigmshifting photocatalysts for their atomic precision in active site engineering,controllable porosity,and exceptional photochemical stability under ambient conditions.However,inherent limitations persist in conventional MOFs,including restricted solar spectrum utilization,inefficient charge carrier separation,and inadequate epoxide activation ability.Recent breakthroughs address these challenges through multiple strategies:ligand engineering,dopant incorporation,and composite construction.This review systematically maps the evolutionary trajectory of MOF‑based photocatalysts,providing mechanistic insights into structure‑activity relationships and providing insights and directions for the design of high‑performance MOF‑based photocatalysts.展开更多
The residues of Al^(3+),Ga^(3+),and In^(3+)in the environment pose an increasingly serious threat to human health and ecosystems.However,their specific and rapid detection remains challenging.In this study,we present ...The residues of Al^(3+),Ga^(3+),and In^(3+)in the environment pose an increasingly serious threat to human health and ecosystems.However,their specific and rapid detection remains challenging.In this study,we present a water‑stable cadmium metal‑organic framework(Cd‑MOF)based luminescence probe,which can detect Al^(3+),Ga^(3+),and In^(3+)ions in aqueous solutions via a luminescence“turn‑on”mode.The corresponding detection limits for the Al^(3+),Ga^(3+),and In^(3+)ions were 2.31,3.06,and 2.78μmol·L^(-1),respectively.This probe operated effectively within a pH range of 3‑10 in an all‑aqueous environment.Investigations into the detection mechanism revealed that this“turn‑on”recognition is attributed to the formation of new structures upon ion interaction.展开更多
As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 n...As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.展开更多
Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environm...Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environmental pollution.Especially,the improper treatment and disposal of toxic sludge generated from different industrial processes or specific wastewater treatment operations exerted significant pressure and threat to hydrosphere,pedosphere,atmosphere and even biosphere.展开更多
Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethy...Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].展开更多
In this work,a novel electrochemical sensor based on covalent organic framework@carbon black@molecularly imprinted polydopamine(COF@CB@MPDA)was developed for selective recognition and determination of ciprofloxacin(CF...In this work,a novel electrochemical sensor based on covalent organic framework@carbon black@molecularly imprinted polydopamine(COF@CB@MPDA)was developed for selective recognition and determination of ciprofloxacin(CF).COF@CB@MPDA possessed good water dispersibility and was synthesized by the selfpolymerization of dopamine under alkaline conditions in the presence of the COF,CB and CF.The high surface area COF enhanced the adsorption of CF,whilst CB gave the composites high electrical conductivity to improve the sensitivity of the proposed COF@CB@MPDA/glassy carbon electrode(GCE)sensor.The specific recognition of CF by COF@CB@MPDA involved hydrogen bonding and van der Waals interactions.Under optimized conditions,the sensor showed a good linear relationship with CF concentration over the range of 5.0×10^(–7)and 1.0×10^(–4)mol/L,with a limit of detection(LOD)of 9.53×10^(–8)mol/L.Further,the developed sensor exhibited high selectivity,repeatability and stability for CF detection in milk and milk powders.The method used to fabricate the COF@CB@MPDA/GCE sensor could be easily adapted for the selective recognition and detection of other antibacterial agents and organic pollutants in the environment.展开更多
Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks l...Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks leads to different electronic states by external stimuli, such as solvent, pH, and water. Herein, we introduced an alkynyl-based building block (ETBA) with high planarity to synthesize two imine-based alkynyl-COFs (ETBA-TAPE-COF and ETBA-PYTA-COF) with high yield, good crystallinity, and chemical stability. Due to the presence of acetylene bonds, ETBA-TAPE-COF does not adopt the completely overlapping AA stacking mode. Slight interlayer displacement occurs along the parallel direction relative to the acetylene linkages, which facilitates lower configurational energy. Additionally, the introduction of pyrene group contributes to high π-electron mobility of ETBA-PYTA-COF. The interactions between electron-withdrawing group (ETBA) and electron-donating group (PYTA) during the processes of protonation and intramolecular charge transfer (ICT) endow ETBA-PYTA-COF with excellent acidochromic and solvatochromic properties, respectively. Based on this, a fluorescence sensor is successfully established, which can be used for rapid response to trace amounts of water in organic solvents. In contrast, ETBA-TAPE-COF does not exhibit these photophysical properties due to its higher HOMO–LUMO gap compared to ETBA-PYTA-COF. This work proposes a new strategy for designing and preparing COFs with unique photophysical properties without introducing additional functional groups.展开更多
Metal organic frameworks(MOFs)have emerged as promising candidates for atmospheric water harvesting due to their high porosity and tunable functionality.Among diverse MOFs,MOF-303 has demonstrated excellent water adso...Metal organic frameworks(MOFs)have emerged as promising candidates for atmospheric water harvesting due to their high porosity and tunable functionality.Among diverse MOFs,MOF-303 has demonstrated excellent water adsorption capacity,rapid desorption kinetics and structural stability.Nevertheless,its practical application is still limited by the time-consuming synthesis process and difficultiesin morphological control.To overcome these challenges,a surfactant-mediated microwaveassisted strategy was proposed.Compared to conventional heating methods,microwave irradiation reduced the reaction duration from 24 h to 1 h with a 13%increase in product yield(from 76%to 89%).However,the accelerated nucleation under microwave irradiation resulted in smaller crystal dimensions(from 50 nm±10 nm to 35 nm±10 nm),therefore inducing severe particle agglomeration.To mitigate this morphological drawback,systematic investigations were conducted to evaluate the effects of surfactants’species on crystal growth.Among the selected surfactants,poly(sodium-p-styrene sulfonate)(PSS)was identifiedas an effective morphology-directing agent,achieving uniform crystal sizes with improved monodispersity through preferential adsorption on specificcrystallographic planes of the MOF.Subsequent optimization of synthetic conditions,including temperature(120-160℃),reaction time(15 min^(-1) h),and surfactant concentration,yielded MOF-303 with a yield of 96.37%,with particle uniformity of(35 nm±10 nm)and predominantly blocky crystal morphology.Water adsorption measurements confirmedthat the surfactant-modifiedMOF-303 retained comparable performance to the surfactant-free counterpart,with a maximum capacity(water/MOF)of 0.214 g·g^(-1) at 35%RH.This study establishes a scalable and tunable synthetic protocol for MOF-303,providing critical insights into microwave-accelerated crystal engineering.展开更多
Ultramicroporous materials(pore dimension<7Å,as defined by IUPAC)have emerged as an intriguing class of porous substances with exceptional potential in molecular separation.Current benchmark materials includin...Ultramicroporous materials(pore dimension<7Å,as defined by IUPAC)have emerged as an intriguing class of porous substances with exceptional potential in molecular separation.Current benchmark materials including zeolites face inherent limitations in achieving hyperfine control of pore metrics,which hinder their ability to discriminate and separate molecules of very close dimensions and properties.Metal-organic frameworks,constructed by deliberate connections of metal nodes and organic linkers,have offered a great solution in addressing these challenges due to their atomic precision that allows angstrom-level engineering of pore width[1-3].展开更多
Dimensionality has great influence on the photo/electro-catalysts properties of covalent organic frameworks(COFs) because of the different electronic and porous structures.However,very rare attention has been paid on ...Dimensionality has great influence on the photo/electro-catalysts properties of covalent organic frameworks(COFs) because of the different electronic and porous structures.However,very rare attention has been paid on the dimensionality and function correlations of COF materials.In the present work,one new two-dimensional phthalocyanine COF,namely 2D-NiPc-COF,and one new three-dimensional phthalocyanine COF,namely 3D-NiPc-COF,were fabricated according to the imide reaction between tetraanhydrides of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(Ⅱ) with [2,2-bipyridine]-5,5-diamine and tetrakis(4-aminophenyl) methane,respectively.The crystalline structures of both COFs are verified by the powder X-ray diffraction analysis,computational simulation,and high resolution transmission electron microscopy measurement.Notably,3D-NiPc-COF with dispersed conjugated modules has high utilization efficiency of NiPc electroactive sites of 26.8%,almost two times higher than the in-plane stacking2D-NiPc-COF measured by electrochemical measurement,in turn resulting in its superior electrocatalytic performance with high CO_(2)-to-CO Faradaic efficiency over 90% in a wide potential window,a large partial CO current density of-13.97 mA/cm^(2) at-0.9 V(vs.reversible hydrogen electrode) to 2D-NiPc-COF.Moreover,3D-NiPc-COF has higher turnover number and turnover frequency of 5741.6 and 0.18 s^(-1) at-0.8 V during 8 h lasting measurement.The present work provides an example for the investigation on the correlation between dimensionality and electrochemical properties of 2D and 3D phthalocyanine COFs.展开更多
文摘Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance.
文摘(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.
基金supported by the National Key Research and Development Program of China(2019YFA0905100)the National Natural Science Foundation of China(21991102,22378227).
文摘Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded organic frameworks(HOFs)have promising application potential for embedding enzymes.In fact,no metal involvement is required,and HOFs exhibit superior biocompatibility,and free access to substrates in mesoporous channels.Herein,a facile in situ growth approach was proposed for the self-assembly of alcohol dehydrogenase encapsulated in HOF.The micron-scale bio-catalytic composite was rapidly synthesized under mild conditions(aqueous phase and ambient temperature)with a controllable embedding rate.The high crystallinity and periodic arrangement channels of HOF were preserved at a high enzyme encapsulation efficiency of 59%.This bio-composite improved the tolerance of the enzyme to the acid-base environment and retained 81%of its initial activity after five cycles of batch hydrogenation involving NADH coenzyme.Based on this controllably synthesized bio-catalytic material and a common lipase,we further developed a two-stage cascade microchemical system and achieved the continuous production of chiral hydroxybutyric acid(R-3-HBA).
基金the financial support provided by the National Natural Science Foundation of China(Nos.22175094,21971113)。
文摘Covalent organic frameworks(COFs)have great potential as adsorbents due to their customizable functionality,low density and high porosity.However,COFs powder exists with poor processing and recycling performance.Moreover,due to the accumulation of COFs nanoparticles,it is not conducive to the full utilization of their surface functional groups.Currently,the strategy of COFs assembling into aerogel can be a good solution to this problem.Herein,we successfully synthesize composite aerogels(CSR)by in-situ self-assembly of two-dimensional COFs and graphene based on crosslinking of sodium alginate.Sodium alginate in the composite improves the mechanical properties of the aerogel,and graphene provides a template for the in-situ growth of COFs.Impressively,CSR aerogels with different COFs and sizes can be prepared by changing the moiety of the ligand and modulating the addition amount of COFs.The prepared CSR aerogels exhibit porous,low density,good processability and good mechanical properties.Among them,the density of CSR-N-1.6 is only 5 mg/cm3,which is the lowest density among the reported COF aerogels so far.Due to these remarkable properties,CSR aerogels perform excellent adsorption and recycling properties for the efficient and rapid removal of organic pollutants(organic dyes and antibiotics)from polluted water.In addition,it is also possible to visually recognize the presence of antibiotics by fluorescence detection.This work not only provides a new strategy for synthesizing COF aerogels,but also accelerates the practical application of COF aerogels and contributes to environmental remediation.
基金support by the National Natural Science Foundation of China(52201077)the Natural Science Foundation of Shandong Province(ZR2022QE191)+1 种基金Elite Scheme of Shandong University of Science and Technology(0104060541123)Talent introduction and Research Start-up Fund of Shandong University of Science and Technology(0104060510124).
文摘Coating microdefects and localized corrosion in coating/metal system are inevitable,accelerating the degradation of metal infrastructure.Early evaluating coating microdefects and detecting corrosion sites are urgent yet remain challenge to achieve.Herein,we propose a robust,universal and efficient fluorescence-based strategy for hierarchical warning of coating damage and metal corrosion by introducing the concepts of damage-induced fluorescence enhancement effect(DIE)and ionic-recognition induced quenching effect(RIQ).The coatings with dualresponsiveness for coating defect and steel corrosion are constructed by incorporating synthesized nanoprobes composed of metal organic frameworks(Ni–Zn-MOFs)loaded with Rhodamine B(RhB@MOFs).The initial damage to the coating causes an immediate intensification of fluorescence,while the specific ionic-recognition characteristic of RhB with Fe3t results in an evident fluorescence quenching,enabling the detection of coating damage and corrosion.Importantly,this nanoprobes are insensitive to the coating matrix and exhibit stable corrosion warning capability across various coating systems.Meanwhile,electrochemical investigations indicate that the impedance values of RM/EP maintain above 10^(8)Ωcm^(2)even after 60 days of immersion.Therefore,the incorporation of fluorescent nanoprobes greatly inhibits the intrusion of electrolytes into polymer and improves the corrosion protection performance of the coating.This powerful strategy towards dual-level damage warning provides insights for the development of long-term smart protective materials.
基金supported by the National Natural Science Foundation of China(No.U2067212)the National Science Fund for Distinguished Young Scholars(No.21925603).
文摘A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
基金financially supported by the National Natural Science Foundation of China(62464010)Spring City Plan-Special Program for Young Talents(K202005007)+3 种基金Yunnan Talents Support Plan for Yong Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Key Laboratory of Artificial Microstructures in Yunnan Higher EducationFrontier Research Team of Kunming University 2023。
文摘Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomers(p-phenylenediamine(Pa),benzidine(BD),and 4,4"-diamino-p-terphenyl(DATP))were used to synthesize a series of two-dimensional covalent-organic frameworks(COFs).The resulting COFs were named TpPa,TpBD,and TpDATP,respectively,and they showed uniform zincophilic sites,different pore sizes,and high Young's moduli on the Zn anode.Among them,TpPa and TpBD showed lower surface work functions and higher ion transfer numbers,which were conducive to uniform galvanizing/stripping zinc and inhibited dendrite growth.Theoretical calculations showed that TpPa and TpBD had wider negative potential region and greater adsorption capacity for Zn2+than TpDATP,providing more electron donor sites to coordinate with Zn^(2+).Symmetric cells protected by TpPa and TpBD stably cycled for more than 2300 h,whereas TpDATP@Zn and the bare zinc symmetric cells failed after around 150 and200 h.The full cells containing TpPa and TpBD modification layers also showed excellent cycling capacity at 1 A/g.This study provides comprehensive insights into the construction of highly reversible Zn anodes via COF modification layers for advanced rechargeable ZIBs.
基金the Natural Science Foundation of Shanghai(23ZR1422600)the Innovative research team of high-level local university in Shanghai for their financial support.
文摘Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other gases.This review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO_(2)capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit interactions.Besides,the main challenges associated with porous frameworks for CO_(2)capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and emphasized.This review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.
基金supported by the National Natural Science Foundation of China(Nos.22375031,22202037,22472023)the Fundamental Research Funds for the Central Universities(Nos.2412023YQ001,2412023QD019,2412024QD014)+1 种基金supported by grants from the seventh batch of Jilin Province Youth Science and Technology Talent Lifting Project(No.QT202305)Science and Technology Development Plan Project of Jilin Province,China(No.20240101192JC)。
文摘The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.
基金the financial support from the National Natural Science Foundation of China(No.22178307)China Southern Power Grid(Grant Nos.0470002022030103HX00002-01).
文摘The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNTs)during the growth process of MOF crystals,synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure.Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin.Simultaneously,the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency.X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co,optimizing the electronic structure.Consequently,the E_(1/2) of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V(vs.RHE),outperforming the catalyst without CNTs.When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells(MFCs)with Nafion-117 as the proton exchange membrane,the maxi-mum power density of MFCs reached approximately 500 mW·m^(-2).
文摘Photocatalytic CO_(2)cycloaddition reaction presents a promising CO_(2)conversion strategy to establish carbon neutrality.Among emerging catalysts,metal‑organic frameworks(MOFs)have been regarded as paradigmshifting photocatalysts for their atomic precision in active site engineering,controllable porosity,and exceptional photochemical stability under ambient conditions.However,inherent limitations persist in conventional MOFs,including restricted solar spectrum utilization,inefficient charge carrier separation,and inadequate epoxide activation ability.Recent breakthroughs address these challenges through multiple strategies:ligand engineering,dopant incorporation,and composite construction.This review systematically maps the evolutionary trajectory of MOF‑based photocatalysts,providing mechanistic insights into structure‑activity relationships and providing insights and directions for the design of high‑performance MOF‑based photocatalysts.
文摘The residues of Al^(3+),Ga^(3+),and In^(3+)in the environment pose an increasingly serious threat to human health and ecosystems.However,their specific and rapid detection remains challenging.In this study,we present a water‑stable cadmium metal‑organic framework(Cd‑MOF)based luminescence probe,which can detect Al^(3+),Ga^(3+),and In^(3+)ions in aqueous solutions via a luminescence“turn‑on”mode.The corresponding detection limits for the Al^(3+),Ga^(3+),and In^(3+)ions were 2.31,3.06,and 2.78μmol·L^(-1),respectively.This probe operated effectively within a pH range of 3‑10 in an all‑aqueous environment.Investigations into the detection mechanism revealed that this“turn‑on”recognition is attributed to the formation of new structures upon ion interaction.
基金support from the National Natural Science Foundation of China(22088101,21733003,22365021,22305132)the Inner Mongolia Autonomous Region“Grassland Talents”Project(2024098)+3 种基金the Inner Mongolia Natural Science Foundation Youth Fund(2023QN02014)The Local Talent Project of Inner Mongolia(12000-15042222)the Basic Research Expenses Supported under 45 Years Old of Inner Mongolia(10000-23112101/036)the“Young Academic Talents”Program of Inner Mongolia University 23600-5233706.
文摘As a class of crystalline porous materials,metal-organic frameworks(MOFs)have shown unique advantages in the fields of catalysis,gas storage and separation,but their inherent microporous structure(pore diameter<2 nm)severely limits their application in scenarios such as macromolecular mass transfer and so on.In order to overcome this re-striction,mesoporous MOFs(meso-MOFs)with a larger aperture(2-50 nm)have attracted much attention due to their potential applications in biological macromolecular catalysis,energy storage and other fields.To date,how to accurately regulate its mesopore topology and pore ordering still faces important technical challenges.
基金supported by National Natural Science Foundation of China(Nos.52370025,22176012)BUCEA Post Graduate Innovation Project(No.PG2024086)。
文摘Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environmental pollution.Especially,the improper treatment and disposal of toxic sludge generated from different industrial processes or specific wastewater treatment operations exerted significant pressure and threat to hydrosphere,pedosphere,atmosphere and even biosphere.
基金supported by National Natural Science Foundation of China(22361031,22308260).
文摘Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].
基金supported by the Project of Key R&D Program of Shandong Province(2023CXGC010712).Geoffrey I.N.
文摘In this work,a novel electrochemical sensor based on covalent organic framework@carbon black@molecularly imprinted polydopamine(COF@CB@MPDA)was developed for selective recognition and determination of ciprofloxacin(CF).COF@CB@MPDA possessed good water dispersibility and was synthesized by the selfpolymerization of dopamine under alkaline conditions in the presence of the COF,CB and CF.The high surface area COF enhanced the adsorption of CF,whilst CB gave the composites high electrical conductivity to improve the sensitivity of the proposed COF@CB@MPDA/glassy carbon electrode(GCE)sensor.The specific recognition of CF by COF@CB@MPDA involved hydrogen bonding and van der Waals interactions.Under optimized conditions,the sensor showed a good linear relationship with CF concentration over the range of 5.0×10^(–7)and 1.0×10^(–4)mol/L,with a limit of detection(LOD)of 9.53×10^(–8)mol/L.Further,the developed sensor exhibited high selectivity,repeatability and stability for CF detection in milk and milk powders.The method used to fabricate the COF@CB@MPDA/GCE sensor could be easily adapted for the selective recognition and detection of other antibacterial agents and organic pollutants in the environment.
基金supported by the National Natural Science Foundation of China(22172055)the Science Fund for Distinguished Young Scholars of Guangdong Province(2023B1515040026)+1 种基金the Key Area Research and Development Program of Guangdong Province(2023B0101200008)the Natural Science Foundation of Guangdong Province(2022A1515011892).
文摘Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks leads to different electronic states by external stimuli, such as solvent, pH, and water. Herein, we introduced an alkynyl-based building block (ETBA) with high planarity to synthesize two imine-based alkynyl-COFs (ETBA-TAPE-COF and ETBA-PYTA-COF) with high yield, good crystallinity, and chemical stability. Due to the presence of acetylene bonds, ETBA-TAPE-COF does not adopt the completely overlapping AA stacking mode. Slight interlayer displacement occurs along the parallel direction relative to the acetylene linkages, which facilitates lower configurational energy. Additionally, the introduction of pyrene group contributes to high π-electron mobility of ETBA-PYTA-COF. The interactions between electron-withdrawing group (ETBA) and electron-donating group (PYTA) during the processes of protonation and intramolecular charge transfer (ICT) endow ETBA-PYTA-COF with excellent acidochromic and solvatochromic properties, respectively. Based on this, a fluorescence sensor is successfully established, which can be used for rapid response to trace amounts of water in organic solvents. In contrast, ETBA-TAPE-COF does not exhibit these photophysical properties due to its higher HOMO–LUMO gap compared to ETBA-PYTA-COF. This work proposes a new strategy for designing and preparing COFs with unique photophysical properties without introducing additional functional groups.
基金financial support from the National Natural Science Foundation of China (22222809, 22308250)the fellowship of the China Postdoctoral Science Foundation(2022TQ0232, 2022M722365)the support from Haihe Laboratory of Sustainable Chemical Transformations
文摘Metal organic frameworks(MOFs)have emerged as promising candidates for atmospheric water harvesting due to their high porosity and tunable functionality.Among diverse MOFs,MOF-303 has demonstrated excellent water adsorption capacity,rapid desorption kinetics and structural stability.Nevertheless,its practical application is still limited by the time-consuming synthesis process and difficultiesin morphological control.To overcome these challenges,a surfactant-mediated microwaveassisted strategy was proposed.Compared to conventional heating methods,microwave irradiation reduced the reaction duration from 24 h to 1 h with a 13%increase in product yield(from 76%to 89%).However,the accelerated nucleation under microwave irradiation resulted in smaller crystal dimensions(from 50 nm±10 nm to 35 nm±10 nm),therefore inducing severe particle agglomeration.To mitigate this morphological drawback,systematic investigations were conducted to evaluate the effects of surfactants’species on crystal growth.Among the selected surfactants,poly(sodium-p-styrene sulfonate)(PSS)was identifiedas an effective morphology-directing agent,achieving uniform crystal sizes with improved monodispersity through preferential adsorption on specificcrystallographic planes of the MOF.Subsequent optimization of synthetic conditions,including temperature(120-160℃),reaction time(15 min^(-1) h),and surfactant concentration,yielded MOF-303 with a yield of 96.37%,with particle uniformity of(35 nm±10 nm)and predominantly blocky crystal morphology.Water adsorption measurements confirmedthat the surfactant-modifiedMOF-303 retained comparable performance to the surfactant-free counterpart,with a maximum capacity(water/MOF)of 0.214 g·g^(-1) at 35%RH.This study establishes a scalable and tunable synthetic protocol for MOF-303,providing critical insights into microwave-accelerated crystal engineering.
基金support from the National Key R&D Program of China(2023YFA1507601)the National Natural Science Foundation of China(52373213,22301176)the Shanghai Pujiang Program(23PJ1405000).
文摘Ultramicroporous materials(pore dimension<7Å,as defined by IUPAC)have emerged as an intriguing class of porous substances with exceptional potential in molecular separation.Current benchmark materials including zeolites face inherent limitations in achieving hyperfine control of pore metrics,which hinder their ability to discriminate and separate molecules of very close dimensions and properties.Metal-organic frameworks,constructed by deliberate connections of metal nodes and organic linkers,have offered a great solution in addressing these challenges due to their atomic precision that allows angstrom-level engineering of pore width[1-3].
基金Financial support from the Natural Science Foundation(NSF) of China(Nos.22205015,22175020,and 22235001)the National Postdoctoral Program for Innovative Talents(No.BX20220032)+1 种基金the China Postdoctoral Science Foundation Funded Project(No.2022BG013)the Fundamental Research Funds for the Central Universities(Nos.00007709 and 00007770)。
文摘Dimensionality has great influence on the photo/electro-catalysts properties of covalent organic frameworks(COFs) because of the different electronic and porous structures.However,very rare attention has been paid on the dimensionality and function correlations of COF materials.In the present work,one new two-dimensional phthalocyanine COF,namely 2D-NiPc-COF,and one new three-dimensional phthalocyanine COF,namely 3D-NiPc-COF,were fabricated according to the imide reaction between tetraanhydrides of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(Ⅱ) with [2,2-bipyridine]-5,5-diamine and tetrakis(4-aminophenyl) methane,respectively.The crystalline structures of both COFs are verified by the powder X-ray diffraction analysis,computational simulation,and high resolution transmission electron microscopy measurement.Notably,3D-NiPc-COF with dispersed conjugated modules has high utilization efficiency of NiPc electroactive sites of 26.8%,almost two times higher than the in-plane stacking2D-NiPc-COF measured by electrochemical measurement,in turn resulting in its superior electrocatalytic performance with high CO_(2)-to-CO Faradaic efficiency over 90% in a wide potential window,a large partial CO current density of-13.97 mA/cm^(2) at-0.9 V(vs.reversible hydrogen electrode) to 2D-NiPc-COF.Moreover,3D-NiPc-COF has higher turnover number and turnover frequency of 5741.6 and 0.18 s^(-1) at-0.8 V during 8 h lasting measurement.The present work provides an example for the investigation on the correlation between dimensionality and electrochemical properties of 2D and 3D phthalocyanine COFs.
