Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct...Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.展开更多
The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative p...The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative potential of metal-organic frameworks(MOFs)as next-generation adsorbents for PM recovery,focusing on their synthesis,functionalization,and multiscale adsorption mechanisms.We critically analyze conventional pyrometallurgical and hydrometallurgical methods and highlight their limitations in terms of selectivity,energy consumption,and secondary pollution.In contrast,MOFs offer tunable porosity,abundant active sites,and tunable surface chemistry,enabling efficient PM capture via synergistic physical and chemical adsorption.Advanced modification techniques,including direct synthesis and post-synthetic modification,are reviewed to propose strategies for enhancing the adsorption kinetics and selectivity for Au,Ag,Pt,and Pd.Key structure-property relationships are established through multiscale characterization and thermodynamic models,revealing the critical roles of hierarchical porosity,soft donor atoms,and framework stability.Industrial challenges,such as aqueous stability and scalability,are addressed via Zr-O bond strengthening,hydrophobic functionalization,and support immobilization.This study consolidates the experimental and theoretical advances in MOF-based PM recovery and provides a roadmap for translating laboratory innovations into practical applications within the circular-economy framework.展开更多
Polyimide-linkage covalent organic frameworks(PI-COFs),as a subclass of the COFs material family,featuring the unique combination of excellent thermal stability of polyimide,tunable pore sizes,as well as high crystall...Polyimide-linkage covalent organic frameworks(PI-COFs),as a subclass of the COFs material family,featuring the unique combination of excellent thermal stability of polyimide,tunable pore sizes,as well as high crystallinity and surface area of COFs,are expected to be a novel type of promising crystalline porous material with potential applications in adsorption and separation,catalysis,chemical sensing,and energy storage.Therefore,it is increasingly important to summarize polyimide-linkage in COFs and related applications and provide in-depth insight to accelerate future development.In this review,we offer a comprehensive overview of recent advancements in PI-COFs,emphasizing their synthesis methods,design principles and applications.Finally,our brief outlooks on the current challenges and future developments of PI-COFs are provided.Overall,this review aims to guide the recent and future development of PI-COFs.展开更多
Cellulose frameworks have emerged as promising materials for light management due to their exceptional light-scattering capabilities and sustainable nature.Conventional biomass-derived cellulose frameworks face a fund...Cellulose frameworks have emerged as promising materials for light management due to their exceptional light-scattering capabilities and sustainable nature.Conventional biomass-derived cellulose frameworks face a fundamental trade-off between haze and transparency,coupled with impractical thicknesses(≥1 mm).Inspired by squid’s skin-peeling mechanism,this work develops a peroxyformic acid(HCOOOH)-enabled precision peeling strategy to isolate intact 10-μm-thick bamboo green(BG)frameworks—100×thinner than wood-based counterparts while achieving an unprecedented optical performance(88%haze with 80%transparency).This performance surpasses delignified biomass(transparency<40%at 1 mm)and matches engineered cellulose composites,yet requires no energy-intensive nanofibrillation.The preserved native cellulose I crystalline structure(64.76%crystallinity)and wax-coated uniaxial fibril alignment(Hermans factor:0.23)contribute to high mechanical strength(903 MPa modulus)and broadband light scattering.As a light-management layer in polycrystalline silicon solar cells,the BG framework boosts photoelectric conversion efficiency by 0.41%absolute(18.74%→19.15%),outperforming synthetic anti-reflective coatings.The work establishes a scalable,waste-to-wealth route for optical-grade cellulose materials in next-generation optoelectronics.展开更多
Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability...Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability.However,precise control and tune the pore size of such frameworks still remains a significant challenge to date.In this study,we constructed supramolecular polymer frameworks using rigid tetrahedral star polyisocyanides with tunable length and sufficiently narrow distribution as building block.First,a series of tetrahedral four-arm star polyisocyanides with controlled chain lengths and narrow molecular weight distributions was prepared via the Pd(Ⅱ)-catalyzed living isocyanide polymerization.Then 2-ureido-4[1H]-pyrimidinone(Upy) unit was installed onto each chain-end of polyisocyanide arms via post-polymerization functionalization.Leveraging the supramolecular hydrogen bonding interactions between the terminal Upy units,well-ordered supramolecular polymer frameworks were readily obtained.Notably,the pore size was dependent on the chain length of the polyisocyanide arms.Precisely control the chain length of polyisocyanide arms,supramolecular polymer frameworks with pore sizes ranging from 5.06 nm to 9.72 nm were achieved.These frameworks,with tunable and large pore apertures,demonstrated exceptional capabilities in encapsulating enzymes of different sizes,such as lipase(TL),horseradish peroxidase(HRP),and glucose oxidase(GOx).The encapsulated enzymes exhibited significantly enhanced catalytic activity and durability.Moreover,the frameworks' tunable and large pore apertures facilitated the co-encapsulation of multiple enzymes,enabling efficient dual-enzyme cascade reactions.展开更多
Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synt...Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synthesized two redox-active PAFs(PAF-305 and PAF-306)with different nitrogen-containing motifs,and demonstrated their application as cathode materials for SIBs.Density functional theory(DFT)calculations reveal that nitrogen-rich PAF-305 exhibits a lower lowest unoccupied molecular orbital(LUMO)energy level(-3.35 eV)and a narrower energy gap(E_(g))(2.40 eV)compared with nitrogen-poor PAF-306.As expected,PAF-305 displays outstanding electrochemical performance,comprising a high reversible capacity of 145.2 mAh g^(-1)at 0.05 A g^(-1)and satisfactory cycling stability with 92% capacity retention over 1000 cycles at 0.2 A g^(-1).Remarkably,PAF-305 maintains robust electrochemical properties across a wide temperature range(-20℃ to 50℃).Through a combination of experimental characterizations and theoretical calculations,the sodium-ion storage mechanism of PAF-305 is elucidated.This study not only provides a promising strategy for exploring other redox-active organic units in the design of novel PAFs,but also expands the potential applications of PAFs in energy storage systems.展开更多
CO_(2)reduction technology can promote the resource utilization of carbon and help alleviate global warming and energy supply pressure.It is an effective way to achieve energy conversion and utilization.Covalent organ...CO_(2)reduction technology can promote the resource utilization of carbon and help alleviate global warming and energy supply pressure.It is an effective way to achieve energy conversion and utilization.Covalent organic frameworks(COFs)are porous crystalline materials formed by connecting organic monomers through covalent bonds.They have the characteristics of functional diversity and rich chemical properties.Their advantages,such as high porosity,a wide range of visible light absorption,and excellent charge separation efficiency,give them good potential in CO_(2)capture,separation,and conversion.Currently,Cu is a key metal in the catalytic CO_(2)reduction reaction(CO_(2)RR)for the preparation of high-value-added chemicals.The preparation of highly stable and large-pore Cu-based COFs using COFs as an ideal sacrificial template for loading Cu can be used to develop high-performance electrocatalysts and photocatalysts.In this review,we discuss the latest advancements in this field,including the development of various Cu-based COFs and their applications as catalysts for CO_(2)RR.Here,we mainly introduce the synthesis strategies,some important characterization information,and the applications of electrocatalytic and photocatalytic CO_(2)conversion using these previously reported Cu-based COFs.展开更多
The practical deployment of lithium metal batteries remains severely constrained,especially under elevated temperatures.Although metal-organic frameworks(MOFs)improve the thermal stability of liquid electrolytes by ca...The practical deployment of lithium metal batteries remains severely constrained,especially under elevated temperatures.Although metal-organic frameworks(MOFs)improve the thermal stability of liquid electrolytes by capturing them in well-ordered sub-nanopores,interparticle voids between MOF particles readily absorb liquid electrolyte,obscuring our understanding of the intrinsic role of nanopores in directing Li^(+)transport.To address this challenge,we introduce a one-dimensional(1D)MOF model architecture that eliminates interparticle effects and enables direct observation of Li^(+)solvation and de-solvation dynamics.Comparative studies of 1D HKUST-1 and ZIF-8 uncover distinct transport behaviors,supported by both experimental measurements and neural network potential-based molecular dynamics simulations.Building on these insights,we construct a hierarchical core-shell MOF architecture by integrating ZIF-8(core)and HKUST-1(shell)onto a hybrid fiber scaffold.This design harnesses the complementary strengths of both MOFs to achieve continuous ion pathways,directional Li^(+)conduction,and improved thermal and electrochemical resilience.展开更多
The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Coval...The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Covalent organic frameworks(COFs) are ideal adsorbents for gold recovery owing to their large surface area,good stability,easily functionalized ability,periodic structures,and definitive nanopores.Herein,a cyano-functionalized COF(COF-CN) with high crystallinity was large-scale prepared under mild conditions for the recovery of gold.The introduction of cyano groups enable COF-CN to exhibit excellent gold recovery performance,which possesses fast adsorption kinetics,high cycling stability,and adsorption capacity up to 663.67 mg/g.Excitingly,COF-CN showed extremely high selectivity for gold ions,even in the presence of various competing cations and anions.The COF-CN maintained excellent selectivity and removal efficiency in gold recovery experiments from WEEE.The facile synthesis of COF-CN and its outstanding selectivity in actual samples make it an attractive opportunity for practical gold recovery.展开更多
Two supramolecular organic frameworks(SOFs)have been constructed from the co-assembly of biimidazolium-derived octacationic components and cucurbit[8]uril in water.Dynamic light scattering and ^(1)H NMR experiments re...Two supramolecular organic frameworks(SOFs)have been constructed from the co-assembly of biimidazolium-derived octacationic components and cucurbit[8]uril in water.Dynamic light scattering and ^(1)H NMR experiments reveal that both SOFs can undergo reversible assembly and disassembly at room temperature.One of the SOFs displays unprecedently high maximum tolerated dose of 120 mg/kg with mice,which improves by 40%compared with the highest value of the reported SOFs.In vitro and in vivo tests show that the SOF can adsorb doxorubicin and overcome the resistance of multidrugresistant MDR A549/ADR tumor cells to realize intracellular delivery,leading to enhanced antitumor efficacy.Moreover,it can also completely inhibit the posttreatment phototoxicity of photofrin and fully neutralize the anticoagulation of both unfractionated heparin and low molecular weight heparins through efficient inclusion and elimination or sequestration mechanism.As the first examples that undergo roomtemperature reversible assembly and disassembly,the new SOFs in principle allow for quantitative analysis of the molecular components in the body that is prerequisite for preclinical evaluation in the future.展开更多
Photosynthesis of hydrogen peroxide(H_(2)O_(2))via oxygen reduction reaction(ORR)and water oxidation reaction(WOR)pathways requires controlled formation of radical intermediates.However,achieving precise control over ...Photosynthesis of hydrogen peroxide(H_(2)O_(2))via oxygen reduction reaction(ORR)and water oxidation reaction(WOR)pathways requires controlled formation of radical intermediates.However,achieving precise control over radical formation in metal-free catalysts remains challenging.Herein,we report a fluorinated COF(Kf-F-COF)featuring framework-bound carbonyl groups as intrinsic radical-generating sites for efficient dual-channel H_(2)O_(2)photosynthesis.This design enables the simultaneous activation of O_(2)and H_(2)O through radical-mediated hydrogen atom transfer processes.Mechanistic studies reveal that fluorination enhances the electron affinity of the carbonyl sites,facilitates diradical formation,and lowers the energy barriers of key reaction steps.As a result,Kf-F-COF achieves a high H_(2)O_(2)production rate of 6.42 mmol g^(-1)h^(-1)and long-term stability under natural sunlight and seawater conditions.This work presents a frameworkcentered radical strategy for dual-pathway H_(2)O_(2)photosynthesis and offers mechanistic insights into regulating COF-based photocatalysts.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
This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with ...This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with 84 students from a middle school selected as the research subjects(44 in the experimental group and 40 in the control group).The experimental group used the reflective feedback model,while the control group used the factual feedback model.The results show that,compared with factual feedback,the reflective feedback model based on the pedagogical agent significantly improves students’problem-solving ability,especially at the action and thinking levels.In addition,this model effectively reduces students’cognitive load,especially in terms of internal and external load.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
Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases ...Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases into the atmosphere contributes to greenhouse effects and generates toxic substances.Developing porous materials for the energy-efficient capture,separation,and recovery of F-gases is highly desired.Recently,as a highly designable porous adsorbents,metal–organic frameworks(MOFs)exhibit excellent selective sorption performance toward F-gases,especially for the recognition and separation of different F-gases with highly similar properties,showing their great potential in F-gases control and recovery.In this review,we discuss the capture and separation of F-gases and their azeotropic,near-azeotropic,and isomeric mixtures in various application scenarios by MOFs,specifically classify and analyze molecular interaction between F-gases and MOFs,and interpret the mechanisms underlying their high performance regarding both adsorption capacity and selectivity,providing a repertoire for future materials design.Challenges faced in the transformation research roadmap of MOFs adsorbent separation technologies toward F-gases are also discussed,and areas for future research endeavors are highlighted.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
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
Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation d...Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs anode.Herein,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for SIBs.Moreover,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 cycles.This work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.展开更多
We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dh...We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.展开更多
The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and...The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and[Mg_(2)(L)_(2)(DMSO)_(3)(H_(2)O)](2)with a 2D(4,4)-net structure.Interestingly,the two compounds exhibit distinct luminescent responses to external mechanical stimuli.1 exhibited exceptional resistance mechanical chromic luminescence(RMCL),which can be attributed to the predominant hydrogen bonds and the presence of high-boiling-point solvent molecules within its structure.2 had a reversible MCL property,which can be attributed to the dominantπ-πweak interactions,coupled with the reversible destruction/restoration of its crystallinity under grinding/fumigation.CCDC:2410963,1;2410964,2.展开更多
文摘Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
基金supported by the National Natural Science Foundation of China(No.52304329)the Yunnan Fundamental Research Projects(No.202201BE070001-003),Guo Lin would like to acknowledge Xing Dian talent support program of Yunnan Province.
文摘The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative potential of metal-organic frameworks(MOFs)as next-generation adsorbents for PM recovery,focusing on their synthesis,functionalization,and multiscale adsorption mechanisms.We critically analyze conventional pyrometallurgical and hydrometallurgical methods and highlight their limitations in terms of selectivity,energy consumption,and secondary pollution.In contrast,MOFs offer tunable porosity,abundant active sites,and tunable surface chemistry,enabling efficient PM capture via synergistic physical and chemical adsorption.Advanced modification techniques,including direct synthesis and post-synthetic modification,are reviewed to propose strategies for enhancing the adsorption kinetics and selectivity for Au,Ag,Pt,and Pd.Key structure-property relationships are established through multiscale characterization and thermodynamic models,revealing the critical roles of hierarchical porosity,soft donor atoms,and framework stability.Industrial challenges,such as aqueous stability and scalability,are addressed via Zr-O bond strengthening,hydrophobic functionalization,and support immobilization.This study consolidates the experimental and theoretical advances in MOF-based PM recovery and provides a roadmap for translating laboratory innovations into practical applications within the circular-economy framework.
基金supported by the National Key R&D Program of China(No.2023YFA1507204)National Natural Science Foundation ofChina(Nos.22475074,22171139,22225109,22302055)+4 种基金Natural Science Foundation of Guangdong Province(No.2023B1515020076)Key Scientific Research Project Plan of Colleges and Universities of Henan Province(No.24B150004)The Double Thousand Talents Plan of Jiangxi Province(No.jxsq2023102003)Project supported by the Guangdong Provincial Key Laboratory of Carbon Dioxide Resource Utilization(No.2024B121201001)Project supportedby the Major Research plan of the National Natural Science Foundation of China(No.92461310).
文摘Polyimide-linkage covalent organic frameworks(PI-COFs),as a subclass of the COFs material family,featuring the unique combination of excellent thermal stability of polyimide,tunable pore sizes,as well as high crystallinity and surface area of COFs,are expected to be a novel type of promising crystalline porous material with potential applications in adsorption and separation,catalysis,chemical sensing,and energy storage.Therefore,it is increasingly important to summarize polyimide-linkage in COFs and related applications and provide in-depth insight to accelerate future development.In this review,we offer a comprehensive overview of recent advancements in PI-COFs,emphasizing their synthesis methods,design principles and applications.Finally,our brief outlooks on the current challenges and future developments of PI-COFs are provided.Overall,this review aims to guide the recent and future development of PI-COFs.
基金supported by National Natural Science Foundation of China(32494793).
文摘Cellulose frameworks have emerged as promising materials for light management due to their exceptional light-scattering capabilities and sustainable nature.Conventional biomass-derived cellulose frameworks face a fundamental trade-off between haze and transparency,coupled with impractical thicknesses(≥1 mm).Inspired by squid’s skin-peeling mechanism,this work develops a peroxyformic acid(HCOOOH)-enabled precision peeling strategy to isolate intact 10-μm-thick bamboo green(BG)frameworks—100×thinner than wood-based counterparts while achieving an unprecedented optical performance(88%haze with 80%transparency).This performance surpasses delignified biomass(transparency<40%at 1 mm)and matches engineered cellulose composites,yet requires no energy-intensive nanofibrillation.The preserved native cellulose I crystalline structure(64.76%crystallinity)and wax-coated uniaxial fibril alignment(Hermans factor:0.23)contribute to high mechanical strength(903 MPa modulus)and broadband light scattering.As a light-management layer in polycrystalline silicon solar cells,the BG framework boosts photoelectric conversion efficiency by 0.41%absolute(18.74%→19.15%),outperforming synthetic anti-reflective coatings.The work establishes a scalable,waste-to-wealth route for optical-grade cellulose materials in next-generation optoelectronics.
基金The National Natural Science Foundation of China (NSFC,Nos.92256201,52273006,22071041,92356302,and 21971052)Natural Science Foundation of Jilin Province (No.20240101181JC) are gratefully appreciated for financial the supportssupported by the User Experiment Assist System of Shanghai Synchrotron Radiation Facility (SSRF)。
文摘Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability.However,precise control and tune the pore size of such frameworks still remains a significant challenge to date.In this study,we constructed supramolecular polymer frameworks using rigid tetrahedral star polyisocyanides with tunable length and sufficiently narrow distribution as building block.First,a series of tetrahedral four-arm star polyisocyanides with controlled chain lengths and narrow molecular weight distributions was prepared via the Pd(Ⅱ)-catalyzed living isocyanide polymerization.Then 2-ureido-4[1H]-pyrimidinone(Upy) unit was installed onto each chain-end of polyisocyanide arms via post-polymerization functionalization.Leveraging the supramolecular hydrogen bonding interactions between the terminal Upy units,well-ordered supramolecular polymer frameworks were readily obtained.Notably,the pore size was dependent on the chain length of the polyisocyanide arms.Precisely control the chain length of polyisocyanide arms,supramolecular polymer frameworks with pore sizes ranging from 5.06 nm to 9.72 nm were achieved.These frameworks,with tunable and large pore apertures,demonstrated exceptional capabilities in encapsulating enzymes of different sizes,such as lipase(TL),horseradish peroxidase(HRP),and glucose oxidase(GOx).The encapsulated enzymes exhibited significantly enhanced catalytic activity and durability.Moreover,the frameworks' tunable and large pore apertures facilitated the co-encapsulation of multiple enzymes,enabling efficient dual-enzyme cascade reactions.
基金supported by the Science&Technology Department of Jilin Province(20230508057RC)。
文摘Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synthesized two redox-active PAFs(PAF-305 and PAF-306)with different nitrogen-containing motifs,and demonstrated their application as cathode materials for SIBs.Density functional theory(DFT)calculations reveal that nitrogen-rich PAF-305 exhibits a lower lowest unoccupied molecular orbital(LUMO)energy level(-3.35 eV)and a narrower energy gap(E_(g))(2.40 eV)compared with nitrogen-poor PAF-306.As expected,PAF-305 displays outstanding electrochemical performance,comprising a high reversible capacity of 145.2 mAh g^(-1)at 0.05 A g^(-1)and satisfactory cycling stability with 92% capacity retention over 1000 cycles at 0.2 A g^(-1).Remarkably,PAF-305 maintains robust electrochemical properties across a wide temperature range(-20℃ to 50℃).Through a combination of experimental characterizations and theoretical calculations,the sodium-ion storage mechanism of PAF-305 is elucidated.This study not only provides a promising strategy for exploring other redox-active organic units in the design of novel PAFs,but also expands the potential applications of PAFs in energy storage systems.
文摘CO_(2)reduction technology can promote the resource utilization of carbon and help alleviate global warming and energy supply pressure.It is an effective way to achieve energy conversion and utilization.Covalent organic frameworks(COFs)are porous crystalline materials formed by connecting organic monomers through covalent bonds.They have the characteristics of functional diversity and rich chemical properties.Their advantages,such as high porosity,a wide range of visible light absorption,and excellent charge separation efficiency,give them good potential in CO_(2)capture,separation,and conversion.Currently,Cu is a key metal in the catalytic CO_(2)reduction reaction(CO_(2)RR)for the preparation of high-value-added chemicals.The preparation of highly stable and large-pore Cu-based COFs using COFs as an ideal sacrificial template for loading Cu can be used to develop high-performance electrocatalysts and photocatalysts.In this review,we discuss the latest advancements in this field,including the development of various Cu-based COFs and their applications as catalysts for CO_(2)RR.Here,we mainly introduce the synthesis strategies,some important characterization information,and the applications of electrocatalytic and photocatalytic CO_(2)conversion using these previously reported Cu-based COFs.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2023-00217581)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(RS-2024-00406724)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(RS-2025-25430676)。
文摘The practical deployment of lithium metal batteries remains severely constrained,especially under elevated temperatures.Although metal-organic frameworks(MOFs)improve the thermal stability of liquid electrolytes by capturing them in well-ordered sub-nanopores,interparticle voids between MOF particles readily absorb liquid electrolyte,obscuring our understanding of the intrinsic role of nanopores in directing Li^(+)transport.To address this challenge,we introduce a one-dimensional(1D)MOF model architecture that eliminates interparticle effects and enables direct observation of Li^(+)solvation and de-solvation dynamics.Comparative studies of 1D HKUST-1 and ZIF-8 uncover distinct transport behaviors,supported by both experimental measurements and neural network potential-based molecular dynamics simulations.Building on these insights,we construct a hierarchical core-shell MOF architecture by integrating ZIF-8(core)and HKUST-1(shell)onto a hybrid fiber scaffold.This design harnesses the complementary strengths of both MOFs to achieve continuous ion pathways,directional Li^(+)conduction,and improved thermal and electrochemical resilience.
基金financially supported by the National Natural Science Foundation of China (No.51972302)。
文摘The recovery of gold from waste electronic and electric equipment(WEEE) has gained great attention with the increased number of WEEE,because it can largely alleviate the pressure on the environment and resources.Covalent organic frameworks(COFs) are ideal adsorbents for gold recovery owing to their large surface area,good stability,easily functionalized ability,periodic structures,and definitive nanopores.Herein,a cyano-functionalized COF(COF-CN) with high crystallinity was large-scale prepared under mild conditions for the recovery of gold.The introduction of cyano groups enable COF-CN to exhibit excellent gold recovery performance,which possesses fast adsorption kinetics,high cycling stability,and adsorption capacity up to 663.67 mg/g.Excitingly,COF-CN showed extremely high selectivity for gold ions,even in the presence of various competing cations and anions.The COF-CN maintained excellent selectivity and removal efficiency in gold recovery experiments from WEEE.The facile synthesis of COF-CN and its outstanding selectivity in actual samples make it an attractive opportunity for practical gold recovery.
基金the National Natural Science Foundation of China(No.21921003 for Z.T.L.and 22201293 for S.B.Y.)Shanghai Sailing Program(No.22YF1458300 for S.B.Y.)for financial support。
文摘Two supramolecular organic frameworks(SOFs)have been constructed from the co-assembly of biimidazolium-derived octacationic components and cucurbit[8]uril in water.Dynamic light scattering and ^(1)H NMR experiments reveal that both SOFs can undergo reversible assembly and disassembly at room temperature.One of the SOFs displays unprecedently high maximum tolerated dose of 120 mg/kg with mice,which improves by 40%compared with the highest value of the reported SOFs.In vitro and in vivo tests show that the SOF can adsorb doxorubicin and overcome the resistance of multidrugresistant MDR A549/ADR tumor cells to realize intracellular delivery,leading to enhanced antitumor efficacy.Moreover,it can also completely inhibit the posttreatment phototoxicity of photofrin and fully neutralize the anticoagulation of both unfractionated heparin and low molecular weight heparins through efficient inclusion and elimination or sequestration mechanism.As the first examples that undergo roomtemperature reversible assembly and disassembly,the new SOFs in principle allow for quantitative analysis of the molecular components in the body that is prerequisite for preclinical evaluation in the future.
基金supported by the National Key R&D Program of China(2022YFA1502902)the National Natural Science Foundation of China(22201209,22271218,22071182,21931007,22301235)+1 种基金the Shaanxi Province Young Talent Support Plan(2023SYJ28)the Start-Up Funding of Tianjin University and Xi’an Jiaotong University。
文摘Photosynthesis of hydrogen peroxide(H_(2)O_(2))via oxygen reduction reaction(ORR)and water oxidation reaction(WOR)pathways requires controlled formation of radical intermediates.However,achieving precise control over radical formation in metal-free catalysts remains challenging.Herein,we report a fluorinated COF(Kf-F-COF)featuring framework-bound carbonyl groups as intrinsic radical-generating sites for efficient dual-channel H_(2)O_(2)photosynthesis.This design enables the simultaneous activation of O_(2)and H_(2)O through radical-mediated hydrogen atom transfer processes.Mechanistic studies reveal that fluorination enhances the electron affinity of the carbonyl sites,facilitates diradical formation,and lowers the energy barriers of key reaction steps.As a result,Kf-F-COF achieves a high H_(2)O_(2)production rate of 6.42 mmol g^(-1)h^(-1)and long-term stability under natural sunlight and seawater conditions.This work presents a frameworkcentered radical strategy for dual-pathway H_(2)O_(2)photosynthesis and offers mechanistic insights into regulating COF-based photocatalysts.
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023 Zhejiang Provincial Department of Education General Project:Research on an interdisciplinary teaching model to promote the development of computational thinking in the context of the new curriculum standards[Grant NO:Y202351596]Key Project of Zhejiang Provincial Education Science Planning:Research on an interdisciplinary teaching model to promote students’computational thinking from multiple analytical perspectives[Grant NO:2025SB103].
文摘This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with 84 students from a middle school selected as the research subjects(44 in the experimental group and 40 in the control group).The experimental group used the reflective feedback model,while the control group used the factual feedback model.The results show that,compared with factual feedback,the reflective feedback model based on the pedagogical agent significantly improves students’problem-solving ability,especially at the action and thinking levels.In addition,this model effectively reduces students’cognitive load,especially in terms of internal and external load.
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funded by the National Key Research and Development Program of China(2022YFE0110500)National Natural Science Foundation of China(22376161,52373154,52103181)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe Interdisciplinary Project in Environmental Science and Engineering of Tongji University(2023-3-YB-02)。
文摘Fluorinated gases(F-gases)play a vital role in the chemical industry and in the fields of air conditioning,refrigeration,health care,and organic synthesis.However,the direct emission of waste gases containing F-gases into the atmosphere contributes to greenhouse effects and generates toxic substances.Developing porous materials for the energy-efficient capture,separation,and recovery of F-gases is highly desired.Recently,as a highly designable porous adsorbents,metal–organic frameworks(MOFs)exhibit excellent selective sorption performance toward F-gases,especially for the recognition and separation of different F-gases with highly similar properties,showing their great potential in F-gases control and recovery.In this review,we discuss the capture and separation of F-gases and their azeotropic,near-azeotropic,and isomeric mixtures in various application scenarios by MOFs,specifically classify and analyze molecular interaction between F-gases and MOFs,and interpret the mechanisms underlying their high performance regarding both adsorption capacity and selectivity,providing a repertoire for future materials design.Challenges faced in the transformation research roadmap of MOFs adsorbent separation technologies toward F-gases are also discussed,and areas for future research endeavors are highlighted.
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financially supported by the National Natural Science Foundation of China(Nos.U1904173 and 52272219)the Key Research Projects of Henan Provincial Department of Education(No.19A150043)+2 种基金the Natural Science Foundation of Henan Province(Nos.202300410330 and 222300420276)the Nanhu Scholars Program for Young Scholars of Xinyang Normal Universitythe Xinyang Normal University Analysis&Testing Center。
文摘Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs anode.Herein,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for SIBs.Moreover,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 cycles.This work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.
文摘We have developed a novel S-scheme heterojunction photocatalyst for the photocatalytic production of hydrogen peroxide(H_(2)O_(2))via a two-electron(2e^(-))oxygen reduction reaction.This S-scheme heterojunction Tph-Dha-COF@Nb_(2)C was fabricated via the in-situ solvothermal growth of Tph-Dha-COF nanostructures on amino-functionalized Nb_(2)C MXene nanoflakes(Nb_(2)C-NH_(2)).The integration of Nb_(2)C significantly extended the visible light absorption of Tph-Dha-COF into the near-infrared region for photocatalytic H_(2)O_(2) production.The Tph-Dha-COF@Nb_(2)C composite demonstrated efficient charge separation,rapid electron transfer,and enhanced oxygen adsorption.Consequently,the Tph-Dha-COF@Nb_(2)C heterojunction exhibited a high H_(2)O_(2) production rate of 1833μmol g^(-1) h^(-1) without sacrificial agents.In-situ Fourier transformed infrared spectroscopy and density functional theory calculations revealed the photocatalytic H_(2)O_(2) production mechanism.The generated H_(2)O_(2) demonstrated enhanced antibacterial activity.This work presents the first application of Nb_(2)C in the photocatalytic synthesis of H_(2)O_(2) and provides a novel strategy for constructing COF-based heterojunctions for photocatalytic H_(2)O_(2) generation and wastewater treatment.
文摘The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and[Mg_(2)(L)_(2)(DMSO)_(3)(H_(2)O)](2)with a 2D(4,4)-net structure.Interestingly,the two compounds exhibit distinct luminescent responses to external mechanical stimuli.1 exhibited exceptional resistance mechanical chromic luminescence(RMCL),which can be attributed to the predominant hydrogen bonds and the presence of high-boiling-point solvent molecules within its structure.2 had a reversible MCL property,which can be attributed to the dominantπ-πweak interactions,coupled with the reversible destruction/restoration of its crystallinity under grinding/fumigation.CCDC:2410963,1;2410964,2.
