A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characteri...A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characterized by means of single-crystal X-ray diffraction, elemental analyses, IR, EPR spectra and thermal analyses. C_ 16H_ 80Cu_4Mo_ 5.5N_ 16O_ 51PV_ 10.5 crystallized in a triclinic system, the space group is P1 with M=2660.63, a= 1.283590(10) nm, b=1.289910(10) nm, c=1.387870(10) nm, V=1.80942(2) nm 3, Z=2, D_x=4.883 g/cm 3, F(000)=2599, μ=6.956 mm -1, (Δ/σ)=0.000, S=1.089. The crystal structure was solved by the direct methods with the final R=0.0752 and wR=0.1988 for 6311 observed reflections with I≥2σ(I). The X-ray crystallography reveals that compound 1 is a novel two-dimensional framework material constructed from the mixed Mo/V polyoxometalate and coordination groups.展开更多
As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and el...As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.展开更多
Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of a...Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.展开更多
Controlled synthesis of two-dimensional covalent organic frameworks(2D COFs),including stoichiometric and sub-stoichiometric variations,is a topic of growing interest due to its potential in gas separation application...Controlled synthesis of two-dimensional covalent organic frameworks(2D COFs),including stoichiometric and sub-stoichiometric variations,is a topic of growing interest due to its potential in gas separation applications.In this study,we successfully synthesized three distinct 2D COFs by carefully adjusting solvent compositions and monomer ratios during the synthesis of[4+4]type COFs.These included a stoichiometric[4+4]type COF and two sub-stoichiometric[4+2]type COFs,featuring unreacted amino or formyl groups.The resulting COFs exhibit different gas adsorption and separation properties.Specifically,sub-stoichiometric COF-DA with residual amino groups shows comparable adsorption capacity for C_(2)H_(2),C_(2)H_(4),and CO_(2)to stoichiometric COF-DAPy.In contrast,sub-stoichiometric COF-Py with residual formyl groups displays enhanced adsorption selectivity for C_(2)H_(2)/C_(2)H_(4)and C_(2)H_(2)/CO_(2)separation,with the C_(2)H_(2)/C_(2)H_(4)selectivity being the highest among reported COFs,attributed to increased pore polarity resulting from the presence of formyl groups.This study not only offers an additional example of substoichiometric COF synthesis but also advocates for further exploration of sub-stoichiometric COF materials,particularly in the field of gas adsorption and separation.展开更多
Two-dimensional(2D)reticular framework films featuring highly accessible surface areas,tunable active sites,and well-defined channels are promising candidates for flexible in-plane micro-supercapacitor(MSC)electrodes....Two-dimensional(2D)reticular framework films featuring highly accessible surface areas,tunable active sites,and well-defined channels are promising candidates for flexible in-plane micro-supercapacitor(MSC)electrodes.However,the interlayer Van der Waals forces in 2D heterojunctions can limit mass/charge transport.Herein,we design a non-Van der Waals force bonded heterojunction of covalent organic frameworks(COFs)and metal–organic frameworks(MOFs)linked by metal-ion coordination.A COF@MOF monolithic nanofilm is constructed by growing MOF(M_(3)(HHTP)_(2))in situ on the COF(COFTD)surface,using nickel(Ni)as the optimal metal to connect the two layers and form a sandwich electrode.We further explore various transition metals in M3(HHTP)2,from manganese(Mn)to zinc(Zn),to adjust the electronic structure and charge redistribution.The optimal MSC-Ni-COF_(TD)@Co_(3)(HHTP)_(2)device exhibits an impressive specific capacitance(1645.3Fcm^(−3)at10mV^(−1)),a high energy density(146.3mWh cm^(−3)),as well as superior cycling and bending stability.This work offers an innovative perspective on overcoming the mass transfer and electron migration limitations of 2D reticular frameworks for miniaturization and wearable energy storage electronics.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
Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are pre...Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are precisely controlled via appropriately selected organic building blocks.This design imparts unique properties to COFs,including exceptional structural stability,tunable pore structure,and surface chemical activity,making them promising for gas separation,catalysis,optoelectronics,and sensing applications.Since Yaghi et al.'s seminal report on COFs in 2005[2],these frameworks have swiftly emerged as a hotspot in the field of materials.Originally,the focus was on fabricating rigid frameworks with static structures and optoelectronic properties.However,the inherently static nature of these frameworks hinders their responsiveness to external stimuli,potentially constraining their functionality in specific applications.Hence,an increasing number of researchers are now directing their attention toward the development of dynamic COFs capable of modifying their structures in response to external stimuli[3].Specifically,dynamic 2D COFs exhibiting enhanced structural responsiveness are of particular interest due to their capability to integrate switchable geometries and porosities with semiconductor building blocks,as well as electron conjugation across COF layers and π-stacked columns,which may enable stimuli-responsive electronic and spin properties[4].展开更多
We introduced bipyridine ligands into a series of two‐dimensional （2D） covalent organic frame‐works （COFs） using 2,2’‐bipyridine‐5,5’‐dicarbaldehyde （2,2’‐BPyDCA） as a component in the mixed building bl...We introduced bipyridine ligands into a series of two‐dimensional （2D） covalent organic frame‐works （COFs） using 2,2’‐bipyridine‐5,5’‐dicarbaldehyde （2,2’‐BPyDCA） as a component in the mixed building blocks. The framework of the COFs was formed by the linkage of imine groups. The ligand content in the COFs was synthetically tuned by the content of 2,2’‐BPyDCA, and thus the amount of metal, palladium（II） acetate, bonded to the nitrogen ligands could be manipulated. Both the bipyri‐dine ligands and imine groups can coordinate with Pd（II） ions, but the loading position can be var‐ied, with one ligand favoring binding in the space between adjacent COFs’ layers and the other lig‐and favoring binding within the pores of the COFs. The Pd（II）‐loaded COFs exhibited good catalytic activity for the Heck reaction.展开更多
Two-dimensional(2D) materials have been demonstrated to exhibit unique properties originating from its 2D nature. In recent years, the construction of 2D materials has become a topic of great interest. This article su...Two-dimensional(2D) materials have been demonstrated to exhibit unique properties originating from its 2D nature. In recent years, the construction of 2D materials has become a topic of great interest. This article summarizes the recent advance of 2D supramolecular organic frameworks(SOFs) which are homogeneously constructed in solution phase through self-assembly of rationally designed building blocks. These 2D SOFs are soluble and still maintain stable network structures in solutions, which exhibit uniqueness not only in structures but also in properties. In this concise review, the SOFs-related background is briefly introduced firstly, followed by outlining the research progress of soluble 2D SOFs from the perspective of monomer design, assembly, and structural characterization.The article ends with a personal outlook on the future development of this new class of supramolecular polymers.展开更多
In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be ut...In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be utilized as organic semiconductors.Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs.We summarize the p-type,n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.展开更多
Covalent organic frameworks（COFs） represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices.In this review,by covering most...Covalent organic frameworks（COFs） represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices.In this review,by covering most of the reported work,we summarized the research progress of two-dimensional（2D）porphyrin- and phthalocyanine-based COFs,with highlighting the synthesis of these 2D COFs via various dynamic covalent reactions and emphasizing their potential applications in different areas.展开更多
Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylfor...Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？ ？ 4.8 ？） functionalized by amino groups.Gas sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.展开更多
A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）triben...A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）tribenzoic acid（H3TMTA）. UPC-32 features a 2 D microporous framework exhibits high adsorption of H2（118.2 cm3/g, 1.05 wt%, at 77 K）, and adsorption heat（Qst） of CO2（34–46 k J/mol）. UPC-32 with narrow distance between layers（3.8 ？） exhibits high selectivity of C3H6/CH4（31.46） and C3H8/CH4（28.04） at298 K and 1 bar. It is the first 2 D Co-MOF that showed selective separation of C3 hydrocarbon from CH4.展开更多
The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an over...The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices.展开更多
As emerging two-dimensional materials, metal-organic framework(MOF) nanosheet composites possess many unique physical and chemical properties, thus being expected to be widely applied in gas separation and adsorption,...As emerging two-dimensional materials, metal-organic framework(MOF) nanosheet composites possess many unique physical and chemical properties, thus being expected to be widely applied in gas separation and adsorption, energy conversion and storage, heterogeneous catalysis, sensing as well as biomedicine. In this review, we first introduce the methods for integrating MOF nanosheets with other materials to prepare multifunctional composites. Next, the applications of MOF nanosheet composites in versatile fields are summarized and discussed. We hope this review will be instructive for researchers in the aspects of designs, preparations and applications of MOF nanosheet composites.展开更多
Molecular hydrogen and spiltover hydrogen storages on five two-dimensional （2D） covalent-organic frameworks （COFs） （PPy-COF, TP-COF, BTP-COF, COF-18 A, and HHTP-DPB COF） are investigated using the grand canonica...Molecular hydrogen and spiltover hydrogen storages on five two-dimensional （2D） covalent-organic frameworks （COFs） （PPy-COF, TP-COF, BTP-COF, COF-18 A, and HHTP-DPB COF） are investigated using the grand canonical Monte Carlo （GCMC） simulations and the density functional theory （DFT）, respectively. The GCMC simulated results show that HHTP-DPB COF has the best performance for hydrogen storage, followed by BTP-COF, TP-COF, COF-18 A, and PPy-COE However, their adsorption amounts at room temperature are all too low to meet the uptake target set by US Department of Energy （US-DOE） and enable practical applications. The effects of pore size, surface area, and isosteric heat of hydrogen on adsorption amount are considered, which indicate that these three factors are all the important factors for determining the H2 adsorption amount. The chemisorptions of spiltover hydrogen atoms on these five COFs represented by the cluster models are investigated using the DFT method. The saturation cluster models are constructed by considering all possible adsorption sites for these cluster models. The average binding energy of a hydrogen atom and the saturation hydrogen storage density are calculated. The large average binding energy indicates that the spillover process may pro- ceed smoothly and reversibly. The saturation hydrogen storage density is much larger than the physisorption uptake of H2 molecules at 298 K and 100 bar （1 bar = 105 Pa）, and is close to or exceeds the 2010 US-DOE target of 6 wt% for hydrogen storage. This suggests that the hydrogen storage capacities of these COFs by spillover may be significantly enhanced. Thus 2D COFs studied in this paper are suitable hydrogen storage media by spillover.展开更多
The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic fra...The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic framework materials(TM-NH MOF,TM=Sc-Zn)are designed,and their electronic and magnetic characters are systematically studied by means of first-principles calculations.Their structural stabilities are examined through binding energies and ab-initio molecular dynamics simulations.Their optimized lattice constants are correlated to the central TM atoms.These 2D TM-NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers.Interestingly,Ni-and Zn-NH MOFs are nonmagnetic semiconductors(SM)with band gaps of 0.41 eV and 0.61 eV,respectively.Co-and Cu-NH MOFs are bipolar magnetic semiconductors(BMS),while Fe-NH MOF monolayer is a half-semiconductor(HSM).Furthermore,the elastic strain could tune their magnetic behaviors and transformation,which ascribes to the charge redistribution of TM-3d states.This work predicts several new 2D magnetic MOF materials,which are promising for applications in spintronics and nanoelectronics.展开更多
A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface...A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.展开更多
This paper investigates ruin,capital injection,and dividends for a two-dimensional risk model.The model posits that surplus levels of insurance companies are governed by a perturbed composite Poisson risk model.This m...This paper investigates ruin,capital injection,and dividends for a two-dimensional risk model.The model posits that surplus levels of insurance companies are governed by a perturbed composite Poisson risk model.This model introduces a dependence between the two surplus levels,present in both the associated perturbations and the claims resulting from common shocks.Critical levels of capital injection and dividends are established for each of the two risks.The surplus levels are observed discretely at fixed intervals,guiding decisions on capital injection,dividends,and ruin at these junctures.This study employs a two-dimensional Fourier cosine series expansion method to approximate the finite time expected discounted operating cost until ruin.The ensuing approximation error is also quantified.The validity and accuracy of the method are corroborated through numerical examples.Furthermore,the research delves into the optimal capital allocation problem.展开更多
As a constituent element of amino acids,nitrogen plays an important role in nourishing plants,animals and other forms of life.Although the atmosphere is rich in nitrogen gas(N_(2)),the highly inert N≡N bond makes it ...As a constituent element of amino acids,nitrogen plays an important role in nourishing plants,animals and other forms of life.Although the atmosphere is rich in nitrogen gas(N_(2)),the highly inert N≡N bond makes it difficult for most organisms to directly utilize N_(2).The supply of nitrogen in the biological chain mainly depends on the slow conversion of N_(2) to ammonia(NH3)by biological nitrogen fixation[1].展开更多
文摘A novel compound [H_2Mo_ 5.5V_ 10.5O_ 40(PO_4)][Cu(en)_2]_4·7H_2O(1) was synthesized from V_2O_5, MoO_3, CuCl_2·2H_2O, en, H_3PO4 and H_2O in an aqueous solution via the hydrothermal method and characterized by means of single-crystal X-ray diffraction, elemental analyses, IR, EPR spectra and thermal analyses. C_ 16H_ 80Cu_4Mo_ 5.5N_ 16O_ 51PV_ 10.5 crystallized in a triclinic system, the space group is P1 with M=2660.63, a= 1.283590(10) nm, b=1.289910(10) nm, c=1.387870(10) nm, V=1.80942(2) nm 3, Z=2, D_x=4.883 g/cm 3, F(000)=2599, μ=6.956 mm -1, (Δ/σ)=0.000, S=1.089. The crystal structure was solved by the direct methods with the final R=0.0752 and wR=0.1988 for 6311 observed reflections with I≥2σ(I). The X-ray crystallography reveals that compound 1 is a novel two-dimensional framework material constructed from the mixed Mo/V polyoxometalate and coordination groups.
基金supported by the NSFC(12474071)Natural Science Foundation of Shandong Province(ZR2024YQ051,ZR2025QB50)+6 种基金Guangdong Basic and Applied Basic Research Foundation(2025A1515011191)the Shanghai Sailing Program(23YF1402200,23YF1402400)funded by Basic Research Program of Jiangsu(BK20240424)Open Research Fund of State Key Laboratory of Crystal Materials(KF2406)Taishan Scholar Foundation of Shandong Province(tsqn202408006,tsqn202507058)Young Talent of Lifting engineering for Science and Technology in Shandong,China(SDAST2024QTB002)the Qilu Young Scholar Program of Shandong University。
文摘As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.
基金supported by the Fundamental Research Funds for the Central Universities(WUT:2024IVA052 and Grant No.104972025KFYjc0089)。
文摘Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.
基金supported by the National Key Research and Development Project of China(No.2022YFE0113800)the National Natural Science Foundation of China(No.22375179)+1 种基金the startup grant(No.2019125016829)in Zhejiang University of Technologypartially supported by the National Innovation and Entrepreneurship Training Program(No.202310337063)。
文摘Controlled synthesis of two-dimensional covalent organic frameworks(2D COFs),including stoichiometric and sub-stoichiometric variations,is a topic of growing interest due to its potential in gas separation applications.In this study,we successfully synthesized three distinct 2D COFs by carefully adjusting solvent compositions and monomer ratios during the synthesis of[4+4]type COFs.These included a stoichiometric[4+4]type COF and two sub-stoichiometric[4+2]type COFs,featuring unreacted amino or formyl groups.The resulting COFs exhibit different gas adsorption and separation properties.Specifically,sub-stoichiometric COF-DA with residual amino groups shows comparable adsorption capacity for C_(2)H_(2),C_(2)H_(4),and CO_(2)to stoichiometric COF-DAPy.In contrast,sub-stoichiometric COF-Py with residual formyl groups displays enhanced adsorption selectivity for C_(2)H_(2)/C_(2)H_(4)and C_(2)H_(2)/CO_(2)separation,with the C_(2)H_(2)/C_(2)H_(4)selectivity being the highest among reported COFs,attributed to increased pore polarity resulting from the presence of formyl groups.This study not only offers an additional example of substoichiometric COF synthesis but also advocates for further exploration of sub-stoichiometric COF materials,particularly in the field of gas adsorption and separation.
基金the National Natural Science Foundation of China(No.22375056,22105058)Key Technology Research and Development Major Program of Hebei Province,China(No.242G4403Z)Hebei(China)Natural Science Foundation(No.B2024208006,B2024208017,B2021208014,B2021208073).
文摘Two-dimensional(2D)reticular framework films featuring highly accessible surface areas,tunable active sites,and well-defined channels are promising candidates for flexible in-plane micro-supercapacitor(MSC)electrodes.However,the interlayer Van der Waals forces in 2D heterojunctions can limit mass/charge transport.Herein,we design a non-Van der Waals force bonded heterojunction of covalent organic frameworks(COFs)and metal–organic frameworks(MOFs)linked by metal-ion coordination.A COF@MOF monolithic nanofilm is constructed by growing MOF(M_(3)(HHTP)_(2))in situ on the COF(COFTD)surface,using nickel(Ni)as the optimal metal to connect the two layers and form a sandwich electrode.We further explore various transition metals in M3(HHTP)2,from manganese(Mn)to zinc(Zn),to adjust the electronic structure and charge redistribution.The optimal MSC-Ni-COF_(TD)@Co_(3)(HHTP)_(2)device exhibits an impressive specific capacitance(1645.3Fcm^(−3)at10mV^(−1)),a high energy density(146.3mWh cm^(−3)),as well as superior cycling and bending stability.This work offers an innovative perspective on overcoming the mass transfer and electron migration limitations of 2D reticular frameworks for miniaturization and wearable energy storage electronics.
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.
基金supported by the National Natural Science Foundation of China(Nos.51902121 and 22372067)。
文摘Covalent organic frameworks(COFs)are two-(2D)or threedimensional(3D)crystalline,porous networks generated by reversible polymerization of organic building blocks[1,2].The structures and functionalities of COFs are precisely controlled via appropriately selected organic building blocks.This design imparts unique properties to COFs,including exceptional structural stability,tunable pore structure,and surface chemical activity,making them promising for gas separation,catalysis,optoelectronics,and sensing applications.Since Yaghi et al.'s seminal report on COFs in 2005[2],these frameworks have swiftly emerged as a hotspot in the field of materials.Originally,the focus was on fabricating rigid frameworks with static structures and optoelectronic properties.However,the inherently static nature of these frameworks hinders their responsiveness to external stimuli,potentially constraining their functionality in specific applications.Hence,an increasing number of researchers are now directing their attention toward the development of dynamic COFs capable of modifying their structures in response to external stimuli[3].Specifically,dynamic 2D COFs exhibiting enhanced structural responsiveness are of particular interest due to their capability to integrate switchable geometries and porosities with semiconductor building blocks,as well as electron conjugation across COF layers and π-stacked columns,which may enable stimuli-responsive electronic and spin properties[4].
基金supported by the National Natural Science Foundation of China(21473196,21403214)the 100‐Talents Program of Chinese Academy of SciencesState Key Laboratory of Fine Chemicals,Dalian University of Technology(KF1415)~~
文摘We introduced bipyridine ligands into a series of two‐dimensional （2D） covalent organic frame‐works （COFs） using 2,2’‐bipyridine‐5,5’‐dicarbaldehyde （2,2’‐BPyDCA） as a component in the mixed building blocks. The framework of the COFs was formed by the linkage of imine groups. The ligand content in the COFs was synthetically tuned by the content of 2,2’‐BPyDCA, and thus the amount of metal, palladium（II） acetate, bonded to the nitrogen ligands could be manipulated. Both the bipyri‐dine ligands and imine groups can coordinate with Pd（II） ions, but the loading position can be var‐ied, with one ligand favoring binding in the space between adjacent COFs’ layers and the other lig‐and favoring binding within the pores of the COFs. The Pd（II）‐loaded COFs exhibited good catalytic activity for the Heck reaction.
基金financially supported by the National Natural Science Foundation of China (Nos. 21472225, 21725404)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDAB20000000)
文摘Two-dimensional(2D) materials have been demonstrated to exhibit unique properties originating from its 2D nature. In recent years, the construction of 2D materials has become a topic of great interest. This article summarizes the recent advance of 2D supramolecular organic frameworks(SOFs) which are homogeneously constructed in solution phase through self-assembly of rationally designed building blocks. These 2D SOFs are soluble and still maintain stable network structures in solutions, which exhibit uniqueness not only in structures but also in properties. In this concise review, the SOFs-related background is briefly introduced firstly, followed by outlining the research progress of soluble 2D SOFs from the perspective of monomer design, assembly, and structural characterization.The article ends with a personal outlook on the future development of this new class of supramolecular polymers.
基金the support from National Program for Thousand Young Talents of Chinathe National Natural Science Foundation of China(No.21544001)Fudan University
文摘In recent years,as a new class of two-dimensional polymer,covalent organic frameworks（COFs） have attracted intensive attention and developed rapidly.This review provides an overview of a type of COFs which can be utilized as organic semiconductors.Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs.We summarize the p-type,n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.
基金supported by National Natural Science Foundation of China(No.21572170)the Research Fund for the Doctoral Program of Higher Education of China(No.20130141110008)+2 种基金the Outstanding Youth Foundation of Hubei Province(No.2015CFA045)the Beijing National Laboratory for Molecular Sciencesthe Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices(No.KFJJ201505)
文摘Covalent organic frameworks（COFs） represent an emerging class of porous crystalline materials and have recently shown interesting applications from catalysis to optoelectronic devices.In this review,by covering most of the reported work,we summarized the research progress of two-dimensional（2D）porphyrin- and phthalocyanine-based COFs,with highlighting the synthesis of these 2D COFs via various dynamic covalent reactions and emphasizing their potential applications in different areas.
基金supported by the grant AX-1593(JCGZ)and AX1730(BC)from the Welch Foundation
文摘Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？ ？ 4.8 ？） functionalized by amino groups.Gas sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.
基金financial support from the National Natural Science Foundation of China (Nos. 21771191, 21571187)Taishan Scholar Foundation (No. ts201511019), the Applied Basic Research Projects of Qingdao (No. 16-5-1-95-jch)the Fundamental Research Funds for the Central Universities (Nos. 16CX05015A, 14CX02213A)
文摘A Co-based two-dimensional（2 D） microporous metal-organic frameworks, [Co2（TMTA）（DMF）2（H2O）2]·NO3-·DMF（UPC-32） has been synthesized based on 4,4’,4’’-（2,4,6-trimethylbenzene-1,3,5-triyl）tribenzoic acid（H3TMTA）. UPC-32 features a 2 D microporous framework exhibits high adsorption of H2（118.2 cm3/g, 1.05 wt%, at 77 K）, and adsorption heat（Qst） of CO2（34–46 k J/mol）. UPC-32 with narrow distance between layers（3.8 ？） exhibits high selectivity of C3H6/CH4（31.46） and C3H8/CH4（28.04） at298 K and 1 bar. It is the first 2 D Co-MOF that showed selective separation of C3 hydrocarbon from CH4.
基金the support from the National Natural Science Foundation of China(22272004,62272041)the Fundamental Research Funds for the Central Universities(YWF-22-L-1256)+1 种基金the National Key R&D Program of China(2023YFC3402600)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.1870011182126)。
文摘The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices.
基金supported by National Natural Science Foundation of China (No.21905195)Natural Science Foundation of Tianjin City (No.20JCYBJC00800)PEIYANG Young Scholars Program of Tianjin University (No.2020XRX-0023)。
文摘As emerging two-dimensional materials, metal-organic framework(MOF) nanosheet composites possess many unique physical and chemical properties, thus being expected to be widely applied in gas separation and adsorption, energy conversion and storage, heterogeneous catalysis, sensing as well as biomedicine. In this review, we first introduce the methods for integrating MOF nanosheets with other materials to prepare multifunctional composites. Next, the applications of MOF nanosheet composites in versatile fields are summarized and discussed. We hope this review will be instructive for researchers in the aspects of designs, preparations and applications of MOF nanosheet composites.
基金supported by the National Natural Science Foundation of China(Grant Nos.11247275 and 11304079)the Young Core Instructor of the Higher Education Institutions of Henan Province+1 种基金the Special Foundation for Fostering Technologic Innovative Talents of Henan University of Technology,China(Grant No.2012CXRC16)the Natural Science Foundation of Education Bureau of Henan Province,China(Grant Nos.2011B140005 and 13A140195)
文摘Molecular hydrogen and spiltover hydrogen storages on five two-dimensional （2D） covalent-organic frameworks （COFs） （PPy-COF, TP-COF, BTP-COF, COF-18 A, and HHTP-DPB COF） are investigated using the grand canonical Monte Carlo （GCMC） simulations and the density functional theory （DFT）, respectively. The GCMC simulated results show that HHTP-DPB COF has the best performance for hydrogen storage, followed by BTP-COF, TP-COF, COF-18 A, and PPy-COE However, their adsorption amounts at room temperature are all too low to meet the uptake target set by US Department of Energy （US-DOE） and enable practical applications. The effects of pore size, surface area, and isosteric heat of hydrogen on adsorption amount are considered, which indicate that these three factors are all the important factors for determining the H2 adsorption amount. The chemisorptions of spiltover hydrogen atoms on these five COFs represented by the cluster models are investigated using the DFT method. The saturation cluster models are constructed by considering all possible adsorption sites for these cluster models. The average binding energy of a hydrogen atom and the saturation hydrogen storage density are calculated. The large average binding energy indicates that the spillover process may pro- ceed smoothly and reversibly. The saturation hydrogen storage density is much larger than the physisorption uptake of H2 molecules at 298 K and 100 bar （1 bar = 105 Pa）, and is close to or exceeds the 2010 US-DOE target of 6 wt% for hydrogen storage. This suggests that the hydrogen storage capacities of these COFs by spillover may be significantly enhanced. Thus 2D COFs studied in this paper are suitable hydrogen storage media by spillover.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62074053,61901161,21906041,and 11774079)the Natural Science Foundation of Henan Province,China(Grant Nos.202300410226,202300410237,and 202300410100)+1 种基金Henan Overseas Expertise Introduction Center for Discipline Innovation(Grant No.CXJD2019005)key scientific research projects of Colleges and universities in Henan Province,China(Grant Nos.21A480004,152102210306,192102310499,and 19B450001).
文摘The ferromagnetism of two-dimensional(2D)materials has aroused great interest in recent years,which may play an important role in the next-generation magnetic devices.Herein,a series of 2D transition metal-organic framework materials(TM-NH MOF,TM=Sc-Zn)are designed,and their electronic and magnetic characters are systematically studied by means of first-principles calculations.Their structural stabilities are examined through binding energies and ab-initio molecular dynamics simulations.Their optimized lattice constants are correlated to the central TM atoms.These 2D TM-NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers.Interestingly,Ni-and Zn-NH MOFs are nonmagnetic semiconductors(SM)with band gaps of 0.41 eV and 0.61 eV,respectively.Co-and Cu-NH MOFs are bipolar magnetic semiconductors(BMS),while Fe-NH MOF monolayer is a half-semiconductor(HSM).Furthermore,the elastic strain could tune their magnetic behaviors and transformation,which ascribes to the charge redistribution of TM-3d states.This work predicts several new 2D magnetic MOF materials,which are promising for applications in spintronics and nanoelectronics.
文摘A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.
基金supported by the Shihezi University High-Level Talents Research Startup Project(Project No.RCZK202521)the National Natural Science Foundation of China(Grant Nos.12271066,11871121,12171405)+1 种基金the Chongqing Natural Science Foundation Joint Fund for Innovation and Development Project(Project No.CSTB2024NSCQLZX0085)the Chongqing Normal University Foundation(Grant No.23XLB018).
文摘This paper investigates ruin,capital injection,and dividends for a two-dimensional risk model.The model posits that surplus levels of insurance companies are governed by a perturbed composite Poisson risk model.This model introduces a dependence between the two surplus levels,present in both the associated perturbations and the claims resulting from common shocks.Critical levels of capital injection and dividends are established for each of the two risks.The surplus levels are observed discretely at fixed intervals,guiding decisions on capital injection,dividends,and ruin at these junctures.This study employs a two-dimensional Fourier cosine series expansion method to approximate the finite time expected discounted operating cost until ruin.The ensuing approximation error is also quantified.The validity and accuracy of the method are corroborated through numerical examples.Furthermore,the research delves into the optimal capital allocation problem.
基金support in China by the Natural Science Foundation of Jiangsu Province of China(No.BK20190744)the National Natural Science Foundation of China(No.21903046)the Jiangsu Specially Appointed Professor Plan。
文摘As a constituent element of amino acids,nitrogen plays an important role in nourishing plants,animals and other forms of life.Although the atmosphere is rich in nitrogen gas(N_(2)),the highly inert N≡N bond makes it difficult for most organisms to directly utilize N_(2).The supply of nitrogen in the biological chain mainly depends on the slow conversion of N_(2) to ammonia(NH3)by biological nitrogen fixation[1].
