In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitr...In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported.Selenization temperature plays a significant role in determining the phases,morphology,and lithium-ion storage performance of the composite.Notably,the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g,surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C-or ZnSe@C-based anodes.Furthermore,ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite.展开更多
Suboptimal treatment of laryngeal squamous cell carcinoma(LSCC)provides poor survival rate.The poor bioavailability,resistance to cetuximab(Cet),and the instability of small interfering RNA(siRNA)limit their efficacy ...Suboptimal treatment of laryngeal squamous cell carcinoma(LSCC)provides poor survival rate.The poor bioavailability,resistance to cetuximab(Cet),and the instability of small interfering RNA(siRNA)limit their efficacy in LSCC therapy.The present study has been aimed to develop a Cet and focal adhesion kinase(FAK)siRNA(siFAK)co-delivery nanosystem.Zeolitic imidazolate framework-8(ZIF-8),with its large specific surface area and pH-responsive properties,is an ideal delivery carrier allowing controlled drug release in the acidic tumor microenvironment.Therefore,Cet was loaded onto ZIF-8 and encapsulated in a TU177 cell membrane(TCM)after the electrostatic adsorption of siFAK.Fourier transform infrared(FTIR)spectroscopy,transmission electron microscopy(TEM),scanning electron microscopy(SEM),zeta potential,X-ray diffraction,and particle size analyses were deployed to characterize Cet/siFAK@ZIF-8@TCM.TU177 cells and subcutaneously transplanted tumor-bearing nude mice were used to evaluate the intracellular uptake,cytotoxicity,in vivo biocompatibility,biodistribution,biosafety,pH responsiveness,and anti-LSCC efficacy of Cet/siFAK@ZIF-8@TCM.After ZIF-8@TCM were loaded with Cet and siFAK,alterations in their physical and crystal structures,particle size,and zeta potential were observed.Meanwhile,the co-delivery system increased the loading of Cet through the electrostatic adsorption of siFAK to Cet-loaded ZIF-8.The intracellular uptake of Cet/siFAK@ZIF-8@TCM also protected siFAK from degradation,effectively decreasing the messenger RNA(mRNA)and protein expression levels of FAK in LSCC cells.The ZIF-8@TCM nanosystem for co-delivery of Cet and siFAK exhibited pH-responsiveness and tumor-targeting capabilities,thereby exerting anti-LSCC effects.Co-delivery of Cet and siFAK via the pH-responsive ZIF-8@TCM system enabled the targeted release of the chemotherapeutic and gene,in turn maximizing their anti-LSCC effect while ensuring biosafety.展开更多
Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spa...Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spacing of layered double hydroxides(LDH)to achieve high electrochemical activity.The hierarchical hollow LDH was prepared from bimetallic zeolitic imidazolate frameworks(ZIF)by a facile cation exchange strategy.Zn and Cu elements were selected as the second metals incorporated in Co-ZIF.The characteristics of the corresponding derivatives were studied.Besides,the transformation mechanism of CoZn-ZIF into nanosheet-assembled hollow Co Zn Ni LDH(denoted as CoZnNi-OH)was systematically investigated.Importantly,the interlayer spacing of CoZnNi-OH expands due to Zn^(2+)incorporation.The prepared CoZnNi-OH offers large surface area,exposed active sites,and rapid mass transfer/diffusion rate,which lead to a significant enhancement in the specific capacitance,rate performance,and cycle stability of CoZnNi-OH electrode.In addition,the aqueous alkaline CoZnNi-OH//Zn showed a maximum energy density/power density of 0.924 m Wh/cm^(2),8.479 m W/cm^(2).This work not only raises an insightful strategy for regulating the morphology and interlayer spacing of LDH,but also provides a reference of designing hollow nickel-based nanomaterials for aqueous batteries.展开更多
Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies.As a subtype of metal-organic frameworks(MOFs),zeolitic imidazolate frameworks(ZIFs)have e...Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies.As a subtype of metal-organic frameworks(MOFs),zeolitic imidazolate frameworks(ZIFs)have exploded in popularity in the field of biomaterials as excellent protective materials with the advantages of conformational flexibility,thermal and chemical stability,and functional controllability.With these superior properties,the applications of ZIF-based materials in combination with various therapies for cancer treatment have grown rapidly in recent years,showing remarkable achievements and great potential.This review elucidates the recent advancements in the use of ZIFs as drug delivery agents for cancer therapy.The structures,synthesis methods,properties,and various modifiers of ZIFs used in oncotherapy are presented.Recent advances in the application of ZIF-based nanoparticles as single or combination tumor treatments are reviewed.Furthermore,the future prospects,potential limitations,and challenges of the application of ZIF-based nanomaterials in cancer treatment are discussed.We except to fully explore the potential of ZIF-based materials to present a clear outline for their application as an effective cancer treatment to help them achieve early clinical application.展开更多
Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysi...Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.展开更多
Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounte...Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounters many issues,such as inconvenient surface modification,fast drug release during blood circulation,undesired damage to major organs,and severe in vivo toxicity.To address the above issues,we developed an Mn-ZIF-90 nanosystem functionalized with an originally designed active-targeting and pH-responsive magnetic resonance imaging(MRI)Y1 receptor ligand[Asn28,Pro30,Trp32]-NPY(25-36)for imaging-guided tumor therapy.After Y1 receptor ligand modification,the Mn-ZIF-90 nanosystem exhibited high drug loading,better blood circulation stability,and dual breast cancer cell membrane and mitochondria targetability,further favoring specific microenvironment-triggered tumor therapy.Meanwhile,this nanosystem showed promising T1-weighted magnetic resonance imaging contrast in vivo in the tumor sites.Especially,this nanosystem with fast clean-up had almost no obvious toxicity and no damage occurred to the major organs in mice.Therefore,this nanosystem shows potential for use in imaging-guided tumor therapy.展开更多
Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowi...Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowing wearable electronics. Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube(CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks(ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction(onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution(10 m Acm^-2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability(97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials(0.82 V at 1 m A cm^-1) and excellent structure stability in the bending tests. These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.展开更多
The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facil...The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facile method for rapidly synthesizing hierarchically porous ZIF-90 nanocrystals(particle sizes of~300 nm)using hydroxyl double salts as intermediates at room temperature.The as-synthesized ZIF-90 contained hierarchical porous structures developed using a crystalline interior and a random stack of multiple nanoparticles.Both the morphology and particle size of ZIF-90 nanocrystals could be tuned by controlling the molar ratio of ICA/Zn^(2+).Note that the as-synthesized hierarchically porous ZIF-90 nanocrystals exhibited higher thermal stability compared with the conventional ZIF-90.Because of the introduction of hierarchical porous structures,the resultant hierarchically porous ZIF-90 nanocrystals showed enhanced toluene adsorption capacity than those of conventional metal organic frameworks and zeolites.展开更多
Freestanding carbon nanofibers loaded with bimetallic hollow nanocage structures were synthesized.The nanocages inherited the rhombic dodecahedral morphology of the zeolitic imidazolate framework(ZIF)precursors,ZIF-8 ...Freestanding carbon nanofibers loaded with bimetallic hollow nanocage structures were synthesized.The nanocages inherited the rhombic dodecahedral morphology of the zeolitic imidazolate framework(ZIF)precursors,ZIF-8 and ZIF-67.As anode materials for lithium-ion batteries(LIBs),the bimetallic nanocage-loaded freestanding carbon nanofibers effectively buffered volume expansions and alleviated pulverization through their different reduction and oxidation potentials.The higher capacities of the composite anodes arose via the formation of the Li_(x)Zn alloy and Li_(2)O by Zn and Co ions,respectively,and the enhanced conductivity conferred by the carbon nanofibers.A synergistic effect of the composite components toward the strong electrochemical performance(688 m A h·g^(-1)at 1200 m A·g^(-1))of the bimetallic nanocage-loaded fibers was demonstrated through the superior long-term stability of the anode(1048 m A h·g^(-1)after 300 cycles at 100 m A·g^(-1)),suggesting that the fabricated anode can be a promising material for use in portable LIBs.展开更多
Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-co...Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.展开更多
Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial abilit...Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.展开更多
To find potential zeolitic imidazolate frameworks(ZIFs)for CO_(2)capture from flue gas,we built 169,898 ZIF models from 84,949 hypothetical zeolite networks.By calculating their lattice energies,accessible volumes to ...To find potential zeolitic imidazolate frameworks(ZIFs)for CO_(2)capture from flue gas,we built 169,898 ZIF models from 84,949 hypothetical zeolite networks.By calculating their lattice energies,accessible volumes to CO_(2),the isosteric adsorption heat(Qst)of H2 O,Henry’s constant ratio(SKH)of CO_(2)/N_(2),percent regenerability(R%),CO_(2)working capacity(ΔN CO_(2)),CO_(2)/N_(2)adsorption selectivity(S CO_(2)/N_(2))and adsorbent performance score(APS),we identi fied 49 hydrophobic ZIF structures that might outplay already-realised ZIFs built from the same imidazolate linkers for CO_(2)capture from flue gas.展开更多
As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting t...As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.展开更多
The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither ...The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither efficient in developing a thermally stable char layer nor reducing the release of toxic byproducts during polymer combustion.In this work,we aim to discuss the effects of zeolitic imidazolate frameworks(ZIFs)on synergistically improving the flame retardancy behaviors in polypropylene(PP)composites,including thermal degradation(evolved gas analysis),free radical reactions in the gaseous phase(in-situ chemiluminescent image analysis),and carbonaceous structure in the condensed phase(micro-morphology and composition analysis).It is found that the transition metals in ZIFs can catalytically accelerate the crosslinking reaction at a lower initial temperature and decrease the amount of hydrocarbon volatiles in the gaseous phase.Once ignited,the embedded ZIFs can firstly bridge adjacent phosphorus chains in the polymer matrix to expand crosslinking degrees and then they are anchored in the developed N-doped phospho-carbonaceous networks after pyrolysis.As a result,more compact char residue structures are observed in the condensed phase for ZIF-reinforced composites.For example,by replacing 2 wt%of IFR with ZIF-67,the peak heat release rate,peak smoke production rate,and peak CO production rate are reduced by 69%,80%,and 72%,respectively,when compared to the conventional composite.These results indicate an excellent solution to resolve inherent fire hazards associated with IFRs in polymers and achieve necessary efficiency for industrial applications.It also provides a new strategy for determining flammability characteristics and combustion mechanisms of polymer composites using in-situ chemiluminescence analysis.展开更多
A novel flower-shaped zeolitic imidazolate framework(ZIF) doped organic-inorganic hybrid monolithic column(ZIF-HMC) was prepared by a simple sol-gel "one-step" method and utilized for efficient capillary mic...A novel flower-shaped zeolitic imidazolate framework(ZIF) doped organic-inorganic hybrid monolithic column(ZIF-HMC) was prepared by a simple sol-gel "one-step" method and utilized for efficient capillary microextraction(CME) of four brominated flame retardants.The prepared monolithic was characterized by Fourier transform infrared,scanning electron microscopy,X-ray photoelectron spectroscopy,energy disperse spectroscopy,and N_(2) adsorption-desorption.The parameters of CME were optimized by orthogonal array design.Under the optimal conditions,the ZIF-HMC showed excellent extraction efficiency,the limit of detection(LODs) and the limit of quantification(LOQs) were in the range of0.52$3.1 mg/L and 1.7$10 mg/L,respectively,and the proposed method demonstrated good recovery(88.8%–116.6%) with the RSD less than 13.6% and a reusability of at least 30 times.The ZIF-HMC possessed great potential for separating organic pollutants and the strategy used here could be extended to prepare other derivatized HMC functionalized monoliths.展开更多
A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tail...A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.展开更多
In this study,we put forward a facile strategy for preparing high-performance composites utilizing epoxy resin and dodecahedral bimetallic imidazolate frameworks as the matrix resin and wear-resisting agents,respectiv...In this study,we put forward a facile strategy for preparing high-performance composites utilizing epoxy resin and dodecahedral bimetallic imidazolate frameworks as the matrix resin and wear-resisting agents,respectively,with varied weight ratios via a combination of sonochemical and solution-mixing methods.The results indicate that the synthesized bimetallic imidazolate frameworks possess a dodecahedral morphology,which is composed of nickel/cobalt transition metals and imidazolium salt organic ligands,dispersing homogeneously within the resin matrix.After carefully investigating the mechanical,dry-sliding and thermal properties,we have clearly demonstrated the significance of the added bimetallic imidazolate frameworks in endowing epoxy composites with excellent wear resistance.As the filler content increases,the epoxy composites display reliable mechanical properties and thermal stabilities.Meanwhile,compared with pure resin,the wear rate is significantly reduced by 92.3%,reaching the lowest value of 0.74×10^(-5)mm^(3)·Nm^(-1).Moreover,various characterizations have been carried out to reveal the wearing mechanism.This study aims to enhance the potential of bimetallic imidazolate frameworks in the applications of creating superior wear-resistant polymeric composites with satisfactory mechanical and thermal properties.展开更多
The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole lin...The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole linkage were synthesized as photocatalysts for H_(2)O_(2)production via the precise N-substituted microenvironment regulation(benzene,pyridine,pyrimidine,and triazine).The corresponding frameworks enable water and dissolved oxygen to reach the catalytic sites easily via planar skeletons and regulation of nitrogen-atom numbers.Additionally,the N-adjustment of heterocycle units in these COFs could significantly regulate the electronic band structures,light-harvesting capacity,and hydrophilic properties.The experimental investigation demonstrated that the photocatalytic process of COFs was composed of a dominant and indirect two-electron(2e^(-))oxygen reduction reaction(ORR).Notably,compared to H-COF(benzene),P-COF(pyridine),and M-COF(pyrimidine),T-COF with triazine unit exhibited the highest H_(2)O_(2)production rate of 42,180μmol·g^(-1)·h^(-1)due to its wider visible light absorption and higher separation efficiency of photogenerated electron-hole pairs.Theoretical investigations confirmed that N-heterocycle units in COFs could precisely modulate the energy barrier related to the formation of*OOH and*O_(2-).This study is expected to provide a new way for rationally designing imidazole-linked COFs as promising photocatalysts for efficiently photocatalytic H_(2)O_(2)generation.展开更多
Adjusting the structure and composition of active sites is a highly effective method for activating linear CO_(2)molecules.Nonetheless,precise control of interfacial chemistry within molecular-scale environments prese...Adjusting the structure and composition of active sites is a highly effective method for activating linear CO_(2)molecules.Nonetheless,precise control of interfacial chemistry within molecular-scale environments presents a significant challenge in heterogeneous catalysis.In our study,we present symmetry-broken Mo-O-Co triple-atom active sites within the hybrid zeolite imidazole framework HZIF-Co Mo.These sites disrupt the electronic balance and create a weak built-in electric field,thus promoting photocatalytic CO_(2)reduction.The CO yield over HZIF-Co Mo is improved to 3.1 mmol g^(-1)h^(-1),which is over four times higher than the parent cobalt-imidazole framework MAF-6-Co.Both experimental and theoretical studies indicate that electronic modulation through the symmetry-breaking Mo-O-Co moiety acts as an organizing knob to accelerate charge separation and result in more carriers participating in the catalytic reaction.This work provides important insights into optimizing site-related electronic structures for targeted photocatalytic reactions.展开更多
Nano Research volume 13,pages2259–2267(2020)Cite this article 277 Accesses 1 Altmetric Metrics details Abstract The incorporation of inorganic fillers into poly(ethyleneoxide)(PEO)-based solid polymer electrolytes(SP...Nano Research volume 13,pages2259–2267(2020)Cite this article 277 Accesses 1 Altmetric Metrics details Abstract The incorporation of inorganic fillers into poly(ethyleneoxide)(PEO)-based solid polymer electrolytes(SPEs)is well known as a low-cost and effective method to improve their mechanical and electrochemical properties.Porous zeolitic imidazolate framework-8(ZIF-8)is firstly used as the filler for PEO-based SPEs in this work.Due to the introduction of ZIF-8,an ionic conductivity of 2.2×10^−5 S/cm(30℃)is achieved for the composite SPE,which is one order of magnitude higher than that of the pure PEO.ZIF-8 also accounts for the broader electrochemical stability window and lithium ion transference number(0.36 at 60℃)of the composite SPE.Moreover,the improved mechanism of ZIF-8 to the composite SPE is investigated by zeta potential and Fourier transform infrared spectrograph characterizations.The stability at the composite SPE/lithium interface is greatly enhanced.The LiFePO4||Li cells using the composite SPE exhibit high capacity and excellent cycling performance at 60℃,i.e.,85%capacity retention with 111 mA·h/g capacity retained after 350 cycles at 0.5 C.In comparison,the cells using the pure PEO show fast capacity decay to 74 mA·h/g maintaining only 68 capacity.These results indicate that the PEO-based SPEs with ZIF-8 are of great promise for the application in solid-state lithium metal batteries.展开更多
基金supported by the National Natural Science Foundation of China(No.22265017)the Open Fund of Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education(No.KF-21-04).
文摘In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported.Selenization temperature plays a significant role in determining the phases,morphology,and lithium-ion storage performance of the composite.Notably,the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g,surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C-or ZnSe@C-based anodes.Furthermore,ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite.
文摘Suboptimal treatment of laryngeal squamous cell carcinoma(LSCC)provides poor survival rate.The poor bioavailability,resistance to cetuximab(Cet),and the instability of small interfering RNA(siRNA)limit their efficacy in LSCC therapy.The present study has been aimed to develop a Cet and focal adhesion kinase(FAK)siRNA(siFAK)co-delivery nanosystem.Zeolitic imidazolate framework-8(ZIF-8),with its large specific surface area and pH-responsive properties,is an ideal delivery carrier allowing controlled drug release in the acidic tumor microenvironment.Therefore,Cet was loaded onto ZIF-8 and encapsulated in a TU177 cell membrane(TCM)after the electrostatic adsorption of siFAK.Fourier transform infrared(FTIR)spectroscopy,transmission electron microscopy(TEM),scanning electron microscopy(SEM),zeta potential,X-ray diffraction,and particle size analyses were deployed to characterize Cet/siFAK@ZIF-8@TCM.TU177 cells and subcutaneously transplanted tumor-bearing nude mice were used to evaluate the intracellular uptake,cytotoxicity,in vivo biocompatibility,biodistribution,biosafety,pH responsiveness,and anti-LSCC efficacy of Cet/siFAK@ZIF-8@TCM.After ZIF-8@TCM were loaded with Cet and siFAK,alterations in their physical and crystal structures,particle size,and zeta potential were observed.Meanwhile,the co-delivery system increased the loading of Cet through the electrostatic adsorption of siFAK to Cet-loaded ZIF-8.The intracellular uptake of Cet/siFAK@ZIF-8@TCM also protected siFAK from degradation,effectively decreasing the messenger RNA(mRNA)and protein expression levels of FAK in LSCC cells.The ZIF-8@TCM nanosystem for co-delivery of Cet and siFAK exhibited pH-responsiveness and tumor-targeting capabilities,thereby exerting anti-LSCC effects.Co-delivery of Cet and siFAK via the pH-responsive ZIF-8@TCM system enabled the targeted release of the chemotherapeutic and gene,in turn maximizing their anti-LSCC effect while ensuring biosafety.
基金supported by the National Natural Science Foundation of China(Nos.52371240,U1904215)Natural Science Foundation of Jiangsu Province(No.BK20200044)Changjiang scholars’program of the Ministry of Education(No.Q2018270)。
文摘Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries.Herein,we co-engineered the hollow architecture and interlayer spacing of layered double hydroxides(LDH)to achieve high electrochemical activity.The hierarchical hollow LDH was prepared from bimetallic zeolitic imidazolate frameworks(ZIF)by a facile cation exchange strategy.Zn and Cu elements were selected as the second metals incorporated in Co-ZIF.The characteristics of the corresponding derivatives were studied.Besides,the transformation mechanism of CoZn-ZIF into nanosheet-assembled hollow Co Zn Ni LDH(denoted as CoZnNi-OH)was systematically investigated.Importantly,the interlayer spacing of CoZnNi-OH expands due to Zn^(2+)incorporation.The prepared CoZnNi-OH offers large surface area,exposed active sites,and rapid mass transfer/diffusion rate,which lead to a significant enhancement in the specific capacitance,rate performance,and cycle stability of CoZnNi-OH electrode.In addition,the aqueous alkaline CoZnNi-OH//Zn showed a maximum energy density/power density of 0.924 m Wh/cm^(2),8.479 m W/cm^(2).This work not only raises an insightful strategy for regulating the morphology and interlayer spacing of LDH,but also provides a reference of designing hollow nickel-based nanomaterials for aqueous batteries.
基金National Natural Science Foundation of China(52073278)the“Medical Science+X”Cross-innovation Team of the Norman Bethune Health Science of Jilin University(2022JBGS10)+2 种基金the Jilin Province Science and Technology Development Program(20190201044JC20230101045JC)the Education Department of Jilin Province(JJKH20231205KJ).
文摘Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies.As a subtype of metal-organic frameworks(MOFs),zeolitic imidazolate frameworks(ZIFs)have exploded in popularity in the field of biomaterials as excellent protective materials with the advantages of conformational flexibility,thermal and chemical stability,and functional controllability.With these superior properties,the applications of ZIF-based materials in combination with various therapies for cancer treatment have grown rapidly in recent years,showing remarkable achievements and great potential.This review elucidates the recent advancements in the use of ZIFs as drug delivery agents for cancer therapy.The structures,synthesis methods,properties,and various modifiers of ZIFs used in oncotherapy are presented.Recent advances in the application of ZIF-based nanoparticles as single or combination tumor treatments are reviewed.Furthermore,the future prospects,potential limitations,and challenges of the application of ZIF-based nanomaterials in cancer treatment are discussed.We except to fully explore the potential of ZIF-based materials to present a clear outline for their application as an effective cancer treatment to help them achieve early clinical application.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51603052 and 51573216)the Fundamental Research Funds for the Central Universities(Grant Nos.18lgpy02 and 16lgjc66).
文摘Metal-organic frameworks(MOFs)have been intensely studied for the past few decades as an enormous family of highly tunable porous materials with promisingly applicable functionalities in adsorption,separation,catalysis,sensing,electrochemistry,and a great number of emerging purposes.As a classic MOF,zeolitic imidazolate framework-8(ZIF-8)is conventionally one of the very few MOF members that has been commercialized with considerable production.
基金financially supported by Natural Science Foundation of China(No.81871411)National Key R&D Program of China(2018YFC0910601)+1 种基金Youth Innovation Promotion Association Foundation of CAS(2017340)The Science&Technology Bureau of Ningbo City(2015B11002).
文摘Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounters many issues,such as inconvenient surface modification,fast drug release during blood circulation,undesired damage to major organs,and severe in vivo toxicity.To address the above issues,we developed an Mn-ZIF-90 nanosystem functionalized with an originally designed active-targeting and pH-responsive magnetic resonance imaging(MRI)Y1 receptor ligand[Asn28,Pro30,Trp32]-NPY(25-36)for imaging-guided tumor therapy.After Y1 receptor ligand modification,the Mn-ZIF-90 nanosystem exhibited high drug loading,better blood circulation stability,and dual breast cancer cell membrane and mitochondria targetability,further favoring specific microenvironment-triggered tumor therapy.Meanwhile,this nanosystem showed promising T1-weighted magnetic resonance imaging contrast in vivo in the tumor sites.Especially,this nanosystem with fast clean-up had almost no obvious toxicity and no damage occurred to the major organs in mice.Therefore,this nanosystem shows potential for use in imaging-guided tumor therapy.
基金financial supports from the National Natural Science Foundation of China(21773293 , 21603264)CAS Pioneer Hundred Talents Program (J. Di)+1 种基金The National Key Research and Development Program of China(2016YFA0203301)Key Research Program of Frontier Science of Chinese Academy of Sciences(QYZDB-SSW-SLH031)
文摘Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowing wearable electronics. Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube(CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks(ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction(onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution(10 m Acm^-2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability(97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials(0.82 V at 1 m A cm^-1) and excellent structure stability in the bending tests. These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.
基金the National Natural Science Foundation of China(No.21576094)the Guangdong Natural Science Foundation(No.2017A030313052)the Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515110706,2019A1515110259 and 2019A1515110535)。
文摘The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facile method for rapidly synthesizing hierarchically porous ZIF-90 nanocrystals(particle sizes of~300 nm)using hydroxyl double salts as intermediates at room temperature.The as-synthesized ZIF-90 contained hierarchical porous structures developed using a crystalline interior and a random stack of multiple nanoparticles.Both the morphology and particle size of ZIF-90 nanocrystals could be tuned by controlling the molar ratio of ICA/Zn^(2+).Note that the as-synthesized hierarchically porous ZIF-90 nanocrystals exhibited higher thermal stability compared with the conventional ZIF-90.Because of the introduction of hierarchical porous structures,the resultant hierarchically porous ZIF-90 nanocrystals showed enhanced toluene adsorption capacity than those of conventional metal organic frameworks and zeolites.
基金supported by the Technology Development Program to Solve Climate Changes of the National Research Foundation(NRF)funded by the Ministry of Science,ICT&Future Planning(NRF-2016M1A2A2936760)supported by Advanced Research Center Program(NRF-2013R1A5A1073861)through the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)contracted through Advanced Space Propulsion Research Center at Seoul National UniversityDeanship of Scientific Research at King Saud University for funding this work through research Group no.RG-1440-111。
文摘Freestanding carbon nanofibers loaded with bimetallic hollow nanocage structures were synthesized.The nanocages inherited the rhombic dodecahedral morphology of the zeolitic imidazolate framework(ZIF)precursors,ZIF-8 and ZIF-67.As anode materials for lithium-ion batteries(LIBs),the bimetallic nanocage-loaded freestanding carbon nanofibers effectively buffered volume expansions and alleviated pulverization through their different reduction and oxidation potentials.The higher capacities of the composite anodes arose via the formation of the Li_(x)Zn alloy and Li_(2)O by Zn and Co ions,respectively,and the enhanced conductivity conferred by the carbon nanofibers.A synergistic effect of the composite components toward the strong electrochemical performance(688 m A h·g^(-1)at 1200 m A·g^(-1))of the bimetallic nanocage-loaded fibers was demonstrated through the superior long-term stability of the anode(1048 m A h·g^(-1)after 300 cycles at 100 m A·g^(-1)),suggesting that the fabricated anode can be a promising material for use in portable LIBs.
基金supports received from the National Natural Science Foundation of China (21776301,21636009)are gratefully acknowledged.
文摘Although zeolitic imidazolate frameworks(ZIFs)have bright prospects in wide fields like gas storage/separation,catalysis and medicine,etc.,their large-scale applications are bottlenecked by the absence of their low-cost commercial production technique.Here,we report an uncon ventional method suitable for environmentally friendly and low-cost mass-production of ZIFs.In this method,taking the synthesis of ZIF-8 as an example,ZnO was used instead of Zn(NO_(3))_(2) in traditional solvent synthesis methods and CO_(2) was introduced to dissolve ZnO in aqueous solution of 2-methylimidazole(HMeim)and form water soluble salt([ZnMeim]^(+)[MeimCOO]^(-))at room temperature.Then,by removing CO_(2) through heating or vacuuming,Meim-ions are produced and instantaneously assemble with[ZnMeim]^(+)s to generate ZIF-8 without any by product.Due to the absence of strong acid anions(such as NO^(-)_(3) and Cl^(-) et al.)in solution,the washing of filter cake required in the conventional approaches could be omitted and the filtrate containing only water and HMeim could be reused completely.This method is really green as no waste gas or liquid generates because CO_(2) and water could be recycled perfectly.It overcomes almost all bottlenecks occurred in commercial production of ZIF-8 when using traditional methods.A pilot plant was established for mass-production of ZIF-8 and hundreds kilograms of ZIF-8 was produced,which indicates that the new method is not only environmentally friendly but also low cost and commercial accessibility.It is expected that the new method would open an avenue for commercial applications of ZIFs.
基金supported by the Excellent Youth Foundation of Henan Scientific Committee,China(222300420018)Key Scientific Research Projects in Universities of Henan Province,China(21zx006)。
文摘Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.
基金supported by the National Key Research and Development Program of China(No.2016YFB0701100)the National Natural Science Foundation of China(Nos.21622102 and 21621001)+1 种基金the National 111 Project(No.B17020)Program for JLUSTIRT,and High Performance Computing Center of Jilin University
文摘To find potential zeolitic imidazolate frameworks(ZIFs)for CO_(2)capture from flue gas,we built 169,898 ZIF models from 84,949 hypothetical zeolite networks.By calculating their lattice energies,accessible volumes to CO_(2),the isosteric adsorption heat(Qst)of H2 O,Henry’s constant ratio(SKH)of CO_(2)/N_(2),percent regenerability(R%),CO_(2)working capacity(ΔN CO_(2)),CO_(2)/N_(2)adsorption selectivity(S CO_(2)/N_(2))and adsorbent performance score(APS),we identi fied 49 hydrophobic ZIF structures that might outplay already-realised ZIFs built from the same imidazolate linkers for CO_(2)capture from flue gas.
基金the financial support from the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation(“Climbing Program”Special Funds,pdjh2023b0145)Guangdong Provincial International Joint Research Center for Energy Storage Materials(2023A0505090009)。
文摘As a prevailing cathode material of lithium-ion batteries(LIBs),LiCoO_(2)(LCO)still encounters the tricky problems of structural collapse,whose morphological engineering and cation doping are crucial for surmounting the mechanical strains and alleviating phase degradation upon cycling.Hereinafter,we propose a strategy using a zeolitic imidazolate framework(ZIF)as the self-sacrificing template to directionally prepare a series of LiNi_(0.1)Co_(0.9)O_(2)(LNCO)with tailorable electrochemical properties.The rational selection of sintering temperature imparts the superiority of the resultant products in lithium storage,during which the sample prepared at 700℃(LNCO-700)outperforms its counterparts in cyclability(156.8 mA h g^(-1)at 1 C for 200 cycles in half cells,1 C=275 mA g^(-1))and rate capability due to the expedited ion/electron transport and the strengthen mechanical robustness.The feasibility of proper Ni doping is also divulged by half/full cell tests and theoretical study,during which LNCO-700(167 mA h g^(-1)at 1 C for 100 cycles in full cells)surpasses LCO-700 in battery performance due to the mitigated phase deterioration,stabilized layered structu re,ameliorated electro nic co nductivity,a nd exalted lithium sto rage activity.This work systematically unveils tailorable electrochemical behaviors of LNCO to better direct their practical application.
文摘The use of intumescent flame retardants(IFRs)is considered an environmentally friendly and cost-effective strategy to suppress potential fire hazards from synthetic polymers.However,some conventional IFRs are neither efficient in developing a thermally stable char layer nor reducing the release of toxic byproducts during polymer combustion.In this work,we aim to discuss the effects of zeolitic imidazolate frameworks(ZIFs)on synergistically improving the flame retardancy behaviors in polypropylene(PP)composites,including thermal degradation(evolved gas analysis),free radical reactions in the gaseous phase(in-situ chemiluminescent image analysis),and carbonaceous structure in the condensed phase(micro-morphology and composition analysis).It is found that the transition metals in ZIFs can catalytically accelerate the crosslinking reaction at a lower initial temperature and decrease the amount of hydrocarbon volatiles in the gaseous phase.Once ignited,the embedded ZIFs can firstly bridge adjacent phosphorus chains in the polymer matrix to expand crosslinking degrees and then they are anchored in the developed N-doped phospho-carbonaceous networks after pyrolysis.As a result,more compact char residue structures are observed in the condensed phase for ZIF-reinforced composites.For example,by replacing 2 wt%of IFR with ZIF-67,the peak heat release rate,peak smoke production rate,and peak CO production rate are reduced by 69%,80%,and 72%,respectively,when compared to the conventional composite.These results indicate an excellent solution to resolve inherent fire hazards associated with IFRs in polymers and achieve necessary efficiency for industrial applications.It also provides a new strategy for determining flammability characteristics and combustion mechanisms of polymer composites using in-situ chemiluminescence analysis.
基金supported by the National Natural Science Foundation of China (Nos.21467028 and 21777129)the Program for Innovative Research Group of Gansu Province+3 种基金China(No.1210RJIA001)Special Fund Project for the Central Government to Guide Local Science and Technology Development (2020)Key Laboratory of Polymer Materials of Gansu Provincethe Key Laboratory of Ecological Environment Related Polymer Materials of Ministry of Education。
文摘A novel flower-shaped zeolitic imidazolate framework(ZIF) doped organic-inorganic hybrid monolithic column(ZIF-HMC) was prepared by a simple sol-gel "one-step" method and utilized for efficient capillary microextraction(CME) of four brominated flame retardants.The prepared monolithic was characterized by Fourier transform infrared,scanning electron microscopy,X-ray photoelectron spectroscopy,energy disperse spectroscopy,and N_(2) adsorption-desorption.The parameters of CME were optimized by orthogonal array design.Under the optimal conditions,the ZIF-HMC showed excellent extraction efficiency,the limit of detection(LODs) and the limit of quantification(LOQs) were in the range of0.52$3.1 mg/L and 1.7$10 mg/L,respectively,and the proposed method demonstrated good recovery(88.8%–116.6%) with the RSD less than 13.6% and a reusability of at least 30 times.The ZIF-HMC possessed great potential for separating organic pollutants and the strategy used here could be extended to prepare other derivatized HMC functionalized monoliths.
基金supported by the National Natural Science Foundation of China (Nos. 11775037 and 21676030)the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology (BM212110)The Postgraduate Innovation Project of Changzhou University (KYCX19_1782)。
文摘A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.
基金support from the Graduate Innovation Fund of Anhui University of Science and Technology(Grant No.2024cx2083)the Innovation Training Program for College Students in Anhui University of Science and Technology(Grant No.S202410361033)。
文摘In this study,we put forward a facile strategy for preparing high-performance composites utilizing epoxy resin and dodecahedral bimetallic imidazolate frameworks as the matrix resin and wear-resisting agents,respectively,with varied weight ratios via a combination of sonochemical and solution-mixing methods.The results indicate that the synthesized bimetallic imidazolate frameworks possess a dodecahedral morphology,which is composed of nickel/cobalt transition metals and imidazolium salt organic ligands,dispersing homogeneously within the resin matrix.After carefully investigating the mechanical,dry-sliding and thermal properties,we have clearly demonstrated the significance of the added bimetallic imidazolate frameworks in endowing epoxy composites with excellent wear resistance.As the filler content increases,the epoxy composites display reliable mechanical properties and thermal stabilities.Meanwhile,compared with pure resin,the wear rate is significantly reduced by 92.3%,reaching the lowest value of 0.74×10^(-5)mm^(3)·Nm^(-1).Moreover,various characterizations have been carried out to reveal the wearing mechanism.This study aims to enhance the potential of bimetallic imidazolate frameworks in the applications of creating superior wear-resistant polymeric composites with satisfactory mechanical and thermal properties.
基金supported by the National Natural Science Foundation of China(Nos.U22A20143,52403288)the Natural Science Foundation of Henan Province(No.242300421073)+3 种基金the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT015)Henan Provincial Science and Technology R&D Program Joint Fund(No.235200810071),Central Plains Elite Young Top-notch Talents,the Key Scientific and Technological Project of Henan Province(No.252102230152)Open Project Program of Yaoshan laboratory(No.2024004)Certificate of Postdoctoral Research Grant in Henan Province and Zhongyuan Institute of Technology Superior Discipline Strength Enhancement Program.
文摘The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole linkage were synthesized as photocatalysts for H_(2)O_(2)production via the precise N-substituted microenvironment regulation(benzene,pyridine,pyrimidine,and triazine).The corresponding frameworks enable water and dissolved oxygen to reach the catalytic sites easily via planar skeletons and regulation of nitrogen-atom numbers.Additionally,the N-adjustment of heterocycle units in these COFs could significantly regulate the electronic band structures,light-harvesting capacity,and hydrophilic properties.The experimental investigation demonstrated that the photocatalytic process of COFs was composed of a dominant and indirect two-electron(2e^(-))oxygen reduction reaction(ORR).Notably,compared to H-COF(benzene),P-COF(pyridine),and M-COF(pyrimidine),T-COF with triazine unit exhibited the highest H_(2)O_(2)production rate of 42,180μmol·g^(-1)·h^(-1)due to its wider visible light absorption and higher separation efficiency of photogenerated electron-hole pairs.Theoretical investigations confirmed that N-heterocycle units in COFs could precisely modulate the energy barrier related to the formation of*OOH and*O_(2-).This study is expected to provide a new way for rationally designing imidazole-linked COFs as promising photocatalysts for efficiently photocatalytic H_(2)O_(2)generation.
基金supported by the National Key Research&Development Program of China(2021YFA1501500)the National Natural Science Foundation of China(22101281)。
文摘Adjusting the structure and composition of active sites is a highly effective method for activating linear CO_(2)molecules.Nonetheless,precise control of interfacial chemistry within molecular-scale environments presents a significant challenge in heterogeneous catalysis.In our study,we present symmetry-broken Mo-O-Co triple-atom active sites within the hybrid zeolite imidazole framework HZIF-Co Mo.These sites disrupt the electronic balance and create a weak built-in electric field,thus promoting photocatalytic CO_(2)reduction.The CO yield over HZIF-Co Mo is improved to 3.1 mmol g^(-1)h^(-1),which is over four times higher than the parent cobalt-imidazole framework MAF-6-Co.Both experimental and theoretical studies indicate that electronic modulation through the symmetry-breaking Mo-O-Co moiety acts as an organizing knob to accelerate charge separation and result in more carriers participating in the catalytic reaction.This work provides important insights into optimizing site-related electronic structures for targeted photocatalytic reactions.
基金This work was financially supported by the Key-Area Research and Development Program of Guangdong Province(Nos.2020B090919001 and 2019B090908001)the Natural Science Foundation of Guangdong Province(No.2019A1515010595)+3 种基金China Postdoctoral Science Foundation(No.2018M640778)International Cooperative Research Program of Shenzhen(No.GJHZ20180411143536149)Shenzhen Key Laboratory of Solid State Batteries(No.ZDSYS201802081843465)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(No.2018B030322001).
文摘Nano Research volume 13,pages2259–2267(2020)Cite this article 277 Accesses 1 Altmetric Metrics details Abstract The incorporation of inorganic fillers into poly(ethyleneoxide)(PEO)-based solid polymer electrolytes(SPEs)is well known as a low-cost and effective method to improve their mechanical and electrochemical properties.Porous zeolitic imidazolate framework-8(ZIF-8)is firstly used as the filler for PEO-based SPEs in this work.Due to the introduction of ZIF-8,an ionic conductivity of 2.2×10^−5 S/cm(30℃)is achieved for the composite SPE,which is one order of magnitude higher than that of the pure PEO.ZIF-8 also accounts for the broader electrochemical stability window and lithium ion transference number(0.36 at 60℃)of the composite SPE.Moreover,the improved mechanism of ZIF-8 to the composite SPE is investigated by zeta potential and Fourier transform infrared spectrograph characterizations.The stability at the composite SPE/lithium interface is greatly enhanced.The LiFePO4||Li cells using the composite SPE exhibit high capacity and excellent cycling performance at 60℃,i.e.,85%capacity retention with 111 mA·h/g capacity retained after 350 cycles at 0.5 C.In comparison,the cells using the pure PEO show fast capacity decay to 74 mA·h/g maintaining only 68 capacity.These results indicate that the PEO-based SPEs with ZIF-8 are of great promise for the application in solid-state lithium metal batteries.
