Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used f...Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate（Ⅱ） in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_（DCP） exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.展开更多
Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt singl...Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt single atoms(Co-SA/CTF)photocatalysts have been synthesized and used for efficient CO_(2) reduction and hydrogen production under visible light irradiation.The resulted Co-SA/CTF demonstrate excellent photocatalytic activity,with the CO and H2 evolution rates reaching 1665.74μmol g^(−1) h^(−1) and 1293.18μmol g^(−1) h^(−1),respectively,far surpassing those of Co nanoparticles anchored CTF and pure CTF.A variety of instrumental analyses collectively indicated that Co single atoms sites served as the reaction center for activating the adsorbed CO_(2) molecules,which significantly improved the CO_(2) reduction performance.Additionally,the introduction of Co single atoms could accelerate the separation/transfer of photogenerated charge carriers,thus boosting the photocatalytic performance.This study envisions a novel strategy for designing efficient photocatalysts for energy conversion and showcases the application of CTFs as attractive support for confining metal single atoms.展开更多
In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, eleme...In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, elemental analysis, SEM, TEM, and Nadsorption-desorption.The results indicate that CTF-DCBT is partially crystalline and has ultramicropore（6.5 A?） as well as high heteroatom contents（11.24 wt% and 12.61 wt% for N and S, respectively）. In addition, the BET surface area and total pore volume of CTF-DCBT are 500 m/g and 0.26 cm/g, respectively. CTF-DCBT possesses excellent thermal stability（450 °C） and chemical stability towards boiling water, 4 M HCl, and 1 M Na OH.The COadsorption capacity of CTF-DCBT is 37.8 cm/g at 1 bar and 25 °C. After six adsorption-desorption cycles, there is no obvious loss of COuptake observed. Due to the ultramicropore and high heteroatom contents, CTF-DCBT has high isosteric heats of adsorption for COand high selectivities of COover Nand CH. At 25 °C, the CO/Nand CO/CHselectivities are 112.5 and 10.3, respectively, which are higher than those of most POFs. Breakthrough curves indicate that CTF-DCBT could effectively separate CO/Nand CO/CHmixtures.展开更多
Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperatur...Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperature carbonization show an apparent variation in electrocatalytic activity toward the ORR dependent on the type of F. The samples synthesized at 900 ℃(FCTF-900) exhibits advantages in terms of high activity, high durability, and methanol-tolerant as an efficient electrocatalyst for ORR, manifests a comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte.展开更多
Flexible covalent organic framework(COF)film has drawn much attention as a promising functional material due to their unique molecular structure and self-supporting property.However,the traditional solvothermal method...Flexible covalent organic framework(COF)film has drawn much attention as a promising functional material due to their unique molecular structure and self-supporting property.However,the traditional solvothermal method of synthesizing flexible COF film is usually complicated,long-term duration and energy-consuming,making it unsuitable for scalable preparation.To address these limitations,a new method combining electrospinning and sacrificial template is proposed to quickly produce triazinebased COF fiber films at room temperature.The method is easy to operate and has a short reaction time(minimum 0.5 h)without dehydration and deoxygenation processes at room temperature,making it suitable for large-scale production(20 cm×30 cm).Different from the unprocessable of COF powder,COF films not only have good flexibility and mechanical properties,but also can be patterned with multiple functions to adapt to various application scenarios.Moreover,the functionality of triazine-structured COF is retained,enabling the use of the films in energy conversion and storage applications.Triazine-based COFs naturally have scalable conjugated structure,thus showing potential photocatalytic probability.Furthermore,the large pore structure of COF films enables loading of phase change materials endowing comprehensive properties of thermal management and flame retardance.This study proposes a strategy for the rapid synthesis of COF fiber films at room temperature and paves the way for multifunctional and high-performance COF based materials.展开更多
The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-ri...The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-rich-group triazine-based covalent organic framework(COF-TzDha)with a desolvation effect is designed as an interlayer for stable,dendrite-free LMA.The abundant triazine rings in COFTzDha as a donor effectively attract lithium ions,while the one-dimensional nanopore structure facilitates lithium-ion migration.The periodic arrangement of polar groups(-OH)in the backbone interacts with electrolyte components(DOL,DME,TFSI-)to form a hydrogen bonding network that slows solvent molecules transport.Therefore,COF-TzDha effectively desolvates lithium ions from the solvent sheath,promoting uniform lithium ion flux and Li plating/stripping.Theoretical calculations verify that COFTzDha with abundant adsorption sites and strong adsorption energy facilitates lithium ion desolvation.Consequently,the introduction of COF-TzDha obtains a high ion mobility(0.75).The Li|COF@PP|Li symmetric cell cycles stably for over 1200 h at 4 mA cm^(-2)/4.0 mA h cm^(-2).The Li|COF@PP|LiFePO_(4)full cell also displays highly stable cycling performance with 600 cycles(75.5%capacity retention,~100% Coulombic efficiency)at 1 C.This work verifies an effective strategy for inducing uniform Li deposition and achieving dendrite-free,stable LMA using a polar-rich-group COF interlayer with a desolvation effect.展开更多
Photoinduced molecular oxygen activation is crucial for artificial photosynthesis.However,metal-free semiconductor photocatalysts with high activation efficiency are still lacking up to now.Herein,two isomorphic tris(...Photoinduced molecular oxygen activation is crucial for artificial photosynthesis.However,metal-free semiconductor photocatalysts with high activation efficiency are still lacking up to now.Herein,two isomorphic tris(triazolo)triazine-based covalent organic frameworks were successfully constructed under solvothermal conditions.And they possess high crystallinity,inherent porosity with large surface area and good stability.Strong electron donor-acceptor skeletons expand the visible light harvesting,also facilitate the charge separation and thus lead to their superior activity of photoinduced molecular oxygen activation including photosynthesis of tetrahydroquinolines and hydrogen peroxide.This work provides a way to improve the efficiency of molecular oxygen activation through the rational design of COFs,and also opens new avenues for the construction of highly active and metal-free photocatalysts toward sustainable solar-to-chemical energy conversion.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
High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carb...High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carboxylic group enriched COF by post-functionalization with detecting antibody(Ab1)and ferrocene(Fc),and used for electrochemical detection of AFP.Due to the small,homogeneous pore size of the COF,Ab1 with a big size was immobilized on the surface of the COF,while Fc with a small size was covalently modified both on the surface and in the pores of COF.The covalently immobilized Ab1 was quite stable and beneficial to specifically detect AFP biomarkers.Meanwhile,the enriched Fc molecules not only improved the conductivity of the COF,but also effectively transferred and amplified the electrochemical signal.This proposed immunosensor exhibited high sensitivity in detecting AFP with a detection limit of 0.39 pg/mL(S/N of 3:1)and a wide linear response range spanning from 1 pg/mL to 100 ng/mL when plotted against logarithmic concentrations.Furthermore,this immunosensor showed excellent selectivity,stability and reproducibility in the testing of real samples.This study presents an innovative prototype for construction of a precious metal-free,antibody-directly-immobilized,simple and stable electrochemical immunoprobe.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
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
Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and effic...Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and efficient energy technologies,are constrained in their performance enhancement by the sluggish oxygen reduction reaction(ORR)kinetics at the cathode,anode CO poisoning(e.g.,from methanol crossover)and intricate water management dilemmas[1].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
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
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
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
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
Covalent organic frameworks have emerged as a hot spot in the field of photocatalysis due to their excellent structural tunability,high specific surface area,high porosity,and good chemical stability.Specifically,they...Covalent organic frameworks have emerged as a hot spot in the field of photocatalysis due to their excellent structural tunability,high specific surface area,high porosity,and good chemical stability.Specifically,they exhibit distinctive optoelectronic features by integrating different molecular building blocks with appropriate links,constructing an π-conjugated system,or introducing electron donor–acceptor units into the conjugated framework.The reasonably adjusted band structure yields excellent photocatalytic activity of covalent organic framework materials.展开更多
Per-and polyfluoroalkyl substances(PFAS)are persistent environmental contaminants that often show an adverse impact on human health.Rational design of porous adsorbents for selective and reversible removal of PFAS,suc...Per-and polyfluoroalkyl substances(PFAS)are persistent environmental contaminants that often show an adverse impact on human health.Rational design of porous adsorbents for selective and reversible removal of PFAS,such as perfluorooctane sulfonate(PFOS),is imperative and challenging.Herein,a Janus strategy based on an ionic covalent organic framework(iCOF-DGCl)composed of the alternately hydrophobic aromatic domains and hydrophilic guanidinium moieites has been proposed to meet the requirement of high-performance adsorbents.iCOF-DGCl shows fast adsorption kinetics(970.9 mg g^(−1)min^(−1))and ultrahigh uptake capacity(2491 mg g^(−1))toward PFOS,making it one of the most effective materials among the reported PFOS adsorbents.Moreover,the PFOS removal by iCOF-DGCl remains highly selective in the presence of disturbing anions,and the adsorbent could be well recovered for reuse.Mechanism studies have demonstrated that the Janus structure units of iCOF-DGCl form both hydrophobic and electrostatic interactions with the amphiphilic PFOS,thus achieving cooperative adsorption of PFOS.This work provides a facile approach based on Janus structure of COFs adsorbent for wastewater remediation.展开更多
Covalent organic frameworks(COFs)are newly developed crystalline substances that are garnering growing interest because of their ultrahigh porosity,crystalline nature,and easy-modified architecture,showing promise in ...Covalent organic frameworks(COFs)are newly developed crystalline substances that are garnering growing interest because of their ultrahigh porosity,crystalline nature,and easy-modified architecture,showing promise in the field of photocatalysis.However,it is difficult for pure COFs materials to achieve excellent photocatalytic hydrogen production due to their severe carrier recombination problems.To mitigate this crucial issue,establishing heterojunction is deemed an effective approach.Nonetheless,many of the metal-containing materials that have been used to construct heterojunctions with COFs own a number of drawbacks,including small specific surface area and rare active sites(for inorganic semiconductor materials),wider bandgaps and higher preparation costs(for MOFs).Therefore,it is necessary to choose metal-free materials that are easy to prepare.Red phosphorus(RP),as a semiconductor material without metal components,with suitable bandgap,moderate redox potential,relatively minimal toxicity,is affordable and readily available.Herein,a range of RP/TpPa-1-COF(RP/TP1C)composites have been successfully prepared through solvothermal method.The two-dimensional structure of the two materials causes strong interactions between the materials,and the construction of heterojunctions effectively inhibits the recombination of photogenic charge carriers.As a consequence,the 9%RP/TP1C composite,with the optimal photocatalytic ability,achieves a photocatalytic H2 evolution rate of 6.93 mmol g^(-1) h^(-1),demonstrating a 10.19-fold increase compared to that of bare RP and a 4.08-fold improvement over that of pure TP1C.This article offers a novel and innovative method for the advancement of efficient COF-based photocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(21373202,21525315)~~
文摘Covalent triazine-based frameworks（CTFs） are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate（Ⅱ） in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_（DCP） exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.
基金financially supported by the National Natural Science Foundation of China(Nos.51672047,21707173)the Youth Talent Support Program of Fujian Province(00387077)the National Natural Science Foundation of Fujian Province(Nos.2019J01648,2019J01226)。
文摘Single-atom catalysts(SACs)have emerged as an advanced frontier in heterogeneous catalysis due to their potential to maximize the atomic efficiency.Herein,covalent triazine-based frameworks(CTFs)confining cobalt single atoms(Co-SA/CTF)photocatalysts have been synthesized and used for efficient CO_(2) reduction and hydrogen production under visible light irradiation.The resulted Co-SA/CTF demonstrate excellent photocatalytic activity,with the CO and H2 evolution rates reaching 1665.74μmol g^(−1) h^(−1) and 1293.18μmol g^(−1) h^(−1),respectively,far surpassing those of Co nanoparticles anchored CTF and pure CTF.A variety of instrumental analyses collectively indicated that Co single atoms sites served as the reaction center for activating the adsorbed CO_(2) molecules,which significantly improved the CO_(2) reduction performance.Additionally,the introduction of Co single atoms could accelerate the separation/transfer of photogenerated charge carriers,thus boosting the photocatalytic performance.This study envisions a novel strategy for designing efficient photocatalysts for energy conversion and showcases the application of CTFs as attractive support for confining metal single atoms.
基金supported by the National Key R&D Program of China(2016YFB0600901)the Natural Science Foundation of China(grant nos.21536001 and 21606007)
文摘In this work, a 2D covalent triazine-based framework was prepared by using 1,3-dicyanobenzo[c]thiophene（DCBT） as monomer to effectively capture CO. The resulting CTF-DCBT was characterized by FT-IR, XPS, PXRD, elemental analysis, SEM, TEM, and Nadsorption-desorption.The results indicate that CTF-DCBT is partially crystalline and has ultramicropore（6.5 A?） as well as high heteroatom contents（11.24 wt% and 12.61 wt% for N and S, respectively）. In addition, the BET surface area and total pore volume of CTF-DCBT are 500 m/g and 0.26 cm/g, respectively. CTF-DCBT possesses excellent thermal stability（450 °C） and chemical stability towards boiling water, 4 M HCl, and 1 M Na OH.The COadsorption capacity of CTF-DCBT is 37.8 cm/g at 1 bar and 25 °C. After six adsorption-desorption cycles, there is no obvious loss of COuptake observed. Due to the ultramicropore and high heteroatom contents, CTF-DCBT has high isosteric heats of adsorption for COand high selectivities of COover Nand CH. At 25 °C, the CO/Nand CO/CHselectivities are 112.5 and 10.3, respectively, which are higher than those of most POFs. Breakthrough curves indicate that CTF-DCBT could effectively separate CO/Nand CO/CHmixtures.
基金Supported by the 1000 Plan Professorship for Young Talents,Hundred Talents Program of Fujian Provincethe Fujian Science and Technology Key Project(Item Number 2016H0043)
文摘Using the bottom-up method, we synthesized a series of perfluorinated covalent triazine-based frameworks(FCTFs) with porous structures for catalysis oxygen reduction reaction(ORR). The evolved FCTFs by high-temperature carbonization show an apparent variation in electrocatalytic activity toward the ORR dependent on the type of F. The samples synthesized at 900 ℃(FCTF-900) exhibits advantages in terms of high activity, high durability, and methanol-tolerant as an efficient electrocatalyst for ORR, manifests a comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte.
基金financially supported by the National Key Research and Development Program of China(2022YFB3806500)the National Natural Science Foundation of China(22273100)+1 种基金Dalian-Institute of Chemical Physics(DICPI202440 and DICP I202218)Dalian-Science and Technology-Innovation Fund(2023JJ12GX023)。
文摘Flexible covalent organic framework(COF)film has drawn much attention as a promising functional material due to their unique molecular structure and self-supporting property.However,the traditional solvothermal method of synthesizing flexible COF film is usually complicated,long-term duration and energy-consuming,making it unsuitable for scalable preparation.To address these limitations,a new method combining electrospinning and sacrificial template is proposed to quickly produce triazinebased COF fiber films at room temperature.The method is easy to operate and has a short reaction time(minimum 0.5 h)without dehydration and deoxygenation processes at room temperature,making it suitable for large-scale production(20 cm×30 cm).Different from the unprocessable of COF powder,COF films not only have good flexibility and mechanical properties,but also can be patterned with multiple functions to adapt to various application scenarios.Moreover,the functionality of triazine-structured COF is retained,enabling the use of the films in energy conversion and storage applications.Triazine-based COFs naturally have scalable conjugated structure,thus showing potential photocatalytic probability.Furthermore,the large pore structure of COF films enables loading of phase change materials endowing comprehensive properties of thermal management and flame retardance.This study proposes a strategy for the rapid synthesis of COF fiber films at room temperature and paves the way for multifunctional and high-performance COF based materials.
基金supported by the National Natural Science Foundation of China(No.51972066)the Natural Science Foundation of Guangdong Province of China(No.2024A1515012499)。
文摘The uneven deposition and high reactivity of lithium-metal anode(LMA)lead to uncontrollable dendrite growth,low Coulombic efficiency,and safety concerns,hindering their commercialization.Here,a representative polar-rich-group triazine-based covalent organic framework(COF-TzDha)with a desolvation effect is designed as an interlayer for stable,dendrite-free LMA.The abundant triazine rings in COFTzDha as a donor effectively attract lithium ions,while the one-dimensional nanopore structure facilitates lithium-ion migration.The periodic arrangement of polar groups(-OH)in the backbone interacts with electrolyte components(DOL,DME,TFSI-)to form a hydrogen bonding network that slows solvent molecules transport.Therefore,COF-TzDha effectively desolvates lithium ions from the solvent sheath,promoting uniform lithium ion flux and Li plating/stripping.Theoretical calculations verify that COFTzDha with abundant adsorption sites and strong adsorption energy facilitates lithium ion desolvation.Consequently,the introduction of COF-TzDha obtains a high ion mobility(0.75).The Li|COF@PP|Li symmetric cell cycles stably for over 1200 h at 4 mA cm^(-2)/4.0 mA h cm^(-2).The Li|COF@PP|LiFePO_(4)full cell also displays highly stable cycling performance with 600 cycles(75.5%capacity retention,~100% Coulombic efficiency)at 1 C.This work verifies an effective strategy for inducing uniform Li deposition and achieving dendrite-free,stable LMA using a polar-rich-group COF interlayer with a desolvation effect.
文摘Photoinduced molecular oxygen activation is crucial for artificial photosynthesis.However,metal-free semiconductor photocatalysts with high activation efficiency are still lacking up to now.Herein,two isomorphic tris(triazolo)triazine-based covalent organic frameworks were successfully constructed under solvothermal conditions.And they possess high crystallinity,inherent porosity with large surface area and good stability.Strong electron donor-acceptor skeletons expand the visible light harvesting,also facilitate the charge separation and thus lead to their superior activity of photoinduced molecular oxygen activation including photosynthesis of tetrahydroquinolines and hydrogen peroxide.This work provides a way to improve the efficiency of molecular oxygen activation through the rational design of COFs,and also opens new avenues for the construction of highly active and metal-free photocatalysts toward sustainable solar-to-chemical energy conversion.
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the Natural Science Foundation of ZhejiangProvince(No.LZ24B020005)the National Natural Science Foundation of China(No.22071040)for financial support.
文摘High-sensitive quantitative determination of alpha-fetoprotein(AFP)is of crucial importance for early clinical diagnosis of cancers.Herein,an AuNPs-free electrochemical immunosensor(Ab1-Fc-COF)was prepared from a carboxylic group enriched COF by post-functionalization with detecting antibody(Ab1)and ferrocene(Fc),and used for electrochemical detection of AFP.Due to the small,homogeneous pore size of the COF,Ab1 with a big size was immobilized on the surface of the COF,while Fc with a small size was covalently modified both on the surface and in the pores of COF.The covalently immobilized Ab1 was quite stable and beneficial to specifically detect AFP biomarkers.Meanwhile,the enriched Fc molecules not only improved the conductivity of the COF,but also effectively transferred and amplified the electrochemical signal.This proposed immunosensor exhibited high sensitivity in detecting AFP with a detection limit of 0.39 pg/mL(S/N of 3:1)and a wide linear response range spanning from 1 pg/mL to 100 ng/mL when plotted against logarithmic concentrations.Furthermore,this immunosensor showed excellent selectivity,stability and reproducibility in the testing of real samples.This study presents an innovative prototype for construction of a precious metal-free,antibody-directly-immobilized,simple and stable electrochemical immunoprobe.
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.
文摘Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and efficient energy technologies,are constrained in their performance enhancement by the sluggish oxygen reduction reaction(ORR)kinetics at the cathode,anode CO poisoning(e.g.,from methanol crossover)and intricate water management dilemmas[1].
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 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.
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.
基金financial support from National Natural Science Foundation of China(52272287,22268003)Yunnan Fundamental Research Projects(202305AF150116,202301AT070027)。
文摘Covalent organic frameworks have emerged as a hot spot in the field of photocatalysis due to their excellent structural tunability,high specific surface area,high porosity,and good chemical stability.Specifically,they exhibit distinctive optoelectronic features by integrating different molecular building blocks with appropriate links,constructing an π-conjugated system,or introducing electron donor–acceptor units into the conjugated framework.The reasonably adjusted band structure yields excellent photocatalytic activity of covalent organic framework materials.
基金the financial support from National Key Research and Development Program(2019YFA0210403)National Natural Science Foundation of China(22001178,21975259)+1 种基金Natural Science Foundation of Hebei Province(B2021202077,B2022202039,C20220313)S&T Program of Hebei(236Z4308G).The authors extend their gratitude to Shiyanjia Lab(www.shiyanjia.com)for XPS measurement.
文摘Per-and polyfluoroalkyl substances(PFAS)are persistent environmental contaminants that often show an adverse impact on human health.Rational design of porous adsorbents for selective and reversible removal of PFAS,such as perfluorooctane sulfonate(PFOS),is imperative and challenging.Herein,a Janus strategy based on an ionic covalent organic framework(iCOF-DGCl)composed of the alternately hydrophobic aromatic domains and hydrophilic guanidinium moieites has been proposed to meet the requirement of high-performance adsorbents.iCOF-DGCl shows fast adsorption kinetics(970.9 mg g^(−1)min^(−1))and ultrahigh uptake capacity(2491 mg g^(−1))toward PFOS,making it one of the most effective materials among the reported PFOS adsorbents.Moreover,the PFOS removal by iCOF-DGCl remains highly selective in the presence of disturbing anions,and the adsorbent could be well recovered for reuse.Mechanism studies have demonstrated that the Janus structure units of iCOF-DGCl form both hydrophobic and electrostatic interactions with the amphiphilic PFOS,thus achieving cooperative adsorption of PFOS.This work provides a facile approach based on Janus structure of COFs adsorbent for wastewater remediation.
基金supported by the National Natural Science Foundation of China(Nos.52071171,52202248,22101105)Liaoning Province Centrally Guided Local Science and Technology Development Fund Program(2024JH6/100700010,2024JH6/100700011)+8 种基金Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(2024-35)Open Research Fund of Guangdong Advanced Carbon Materials Co.,Ltd.(Kargen-2024B1001),and Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)T.M.acknowledged the Australian Research Council(ARC)through Future Fellowship(FT210100298)Discovery Project(DP220100603)Linkage Project(LP210200504,LP220100088,LP230200897)Industrial Transformation Research Hub(IH240100009)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA's Transformative Research Accelerating Commercialisation Program(TM021)European Commission's Australia-Spain Network for Innovation and Research Excellence(AuSpire)。
文摘Covalent organic frameworks(COFs)are newly developed crystalline substances that are garnering growing interest because of their ultrahigh porosity,crystalline nature,and easy-modified architecture,showing promise in the field of photocatalysis.However,it is difficult for pure COFs materials to achieve excellent photocatalytic hydrogen production due to their severe carrier recombination problems.To mitigate this crucial issue,establishing heterojunction is deemed an effective approach.Nonetheless,many of the metal-containing materials that have been used to construct heterojunctions with COFs own a number of drawbacks,including small specific surface area and rare active sites(for inorganic semiconductor materials),wider bandgaps and higher preparation costs(for MOFs).Therefore,it is necessary to choose metal-free materials that are easy to prepare.Red phosphorus(RP),as a semiconductor material without metal components,with suitable bandgap,moderate redox potential,relatively minimal toxicity,is affordable and readily available.Herein,a range of RP/TpPa-1-COF(RP/TP1C)composites have been successfully prepared through solvothermal method.The two-dimensional structure of the two materials causes strong interactions between the materials,and the construction of heterojunctions effectively inhibits the recombination of photogenic charge carriers.As a consequence,the 9%RP/TP1C composite,with the optimal photocatalytic ability,achieves a photocatalytic H2 evolution rate of 6.93 mmol g^(-1) h^(-1),demonstrating a 10.19-fold increase compared to that of bare RP and a 4.08-fold improvement over that of pure TP1C.This article offers a novel and innovative method for the advancement of efficient COF-based photocatalysts.
