Photothermal conversion attracted lots of attention in the past years and sorts of materials were explored to enhance photothermal efficiency.In the past years,solar-driven desalination by photothermal conversion was ...Photothermal conversion attracted lots of attention in the past years and sorts of materials were explored to enhance photothermal efficiency.In the past years,solar-driven desalination by photothermal conversion was proposed to release the shortage of fresh water and then it was considered much more important to prepare photothermal materials on large scales with high performance and low cost.In this review,we summarized the works on carbon-based photothermal materials in the past years,including the preparation as well as their application in steam generation.From these works,we give an outlook on the difficulties and chances of how to design and prepare carbon-based photothermal materials.展开更多
The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the ther...The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.展开更多
The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielec...The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielectric loss.However,the validity of this proposition at high frequencies remains uncertain.To scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic ring.The introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry conditions.The dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)conditions.Furthermore,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic nature.Molecular simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water molecules.Despite sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality films.Our research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.展开更多
Single atom catalysts have been recognized as potential catalysts to fabricate electrochemical biosensors,due to their unexpected catalytic selectivity and activity.Here,we designed and fabricated an ultrasensitive do...Single atom catalysts have been recognized as potential catalysts to fabricate electrochemical biosensors,due to their unexpected catalytic selectivity and activity.Here,we designed and fabricated an ultrasensitive dopamine(DA)sensor based on the flower-like MoS_(2) embellished with single Ni site catalyst(Ni-MoS_(2)).The limit of detection could achieve 1 pM in phosphate buffer solution(PBS,pH=7.4),1 pM in bovine serum(pH=7.4),and 100 pM in artificial urine(pH=6.8).The excellent sensing performance was attributed to the Ni single atom axial anchoring on the Mo atom in the MoS_(2) basal plane with the Ni-S_(3) structure.Both the experiment and density functional theory(DFT)results certify that this structural feature is more favorable for the adsorption and electron transfer of DA on Ni atoms.The high proportion of Ni active sites on MoS_(2) basal plane effectively enhanced the intrinsic electronic conductivity and electrochemical activity toward DA.The successful establishment of this sensor gives a new guide to expand the field of single atom catalyst in the application of biosensors.展开更多
Artificial soft actuators,featured with non-equilibrium internal circumstance and fast,programmable shape transformations,have attracted strong research interest recently due to their flexibility,highly controllable,a...Artificial soft actuators,featured with non-equilibrium internal circumstance and fast,programmable shape transformations,have attracted strong research interest recently due to their flexibility,highly controllable,and designability.However,wireless soft actuators,achieving the locomotion on different large slopes with multiple energy conversion,have been rarely reported.Herein,we create a asymmetric bilayer strategy to construct autonomous soft crawler via“breathing”moisture to motivate the mechanical deformation.The soft crawlers present conspicuous performances including periodic tumbler locomotion predicted via improved Timoshenko’s equation,multiple reversible shape-morphing(circle,helix,despiralization,etc.)determined by their fiber orientation,controlled drive mode(front drive and rear drive)and rapid climb speed(4.76 cm/min)at wide slope angles.Through architecture design,they can be series-wound or shunt-wound to construct multijoint complex actuators.Besides climbing,a intelligent soft ring-pull with admirable cycle performance for preventing overheating or something untouchable,has been proposed.The soft crawlers also realize multiple energy conversion to be actuated by light irradiation.We envision that this soft crawler system has an enormous potential in intelligent machine,microscopic diagnosis and treatment,biosensing,energy harvesting and conversion.展开更多
Quasi solid-state succinonitrile(SN)-based polymer electrolytes have emerged for lithium-metal batteries due to their excellent ionconductivity at room temperature,wide electrochemical stability window(ESW,usually>...Quasi solid-state succinonitrile(SN)-based polymer electrolytes have emerged for lithium-metal batteries due to their excellent ionconductivity at room temperature,wide electrochemical stability window(ESW,usually>5 V).However,the practical application of these solid SN-based polymer electrolytes is hampered by the flammability and the inherent instability of SN to Li-metal anode.In this work,solid SN-based polymer electrolytes were prepared with succinonitrile,ethoxylated trimethylolpropane triacrylate(ETPTA),triethyl phosphate(TEP)and fluoroethylene carbonate for Li-metal battery via in situ polymerization method.The SN-based polymer electrolytes with 5 wt%triethyl phosphate and FEC showed good nonflammability,superior ion-conductivity as high as 1.01×10^(-3)S/cm,and wide ESW of 5.41 V.This SN-based polymer electrolyte also exhibited excellent interfacial compatibility to lithium metal anode.And it also delivered a high specific capacity of 156m Ah/g at 0.2 C at ambient temperature,and presented stable cycling at 1.0 C with a specific capacity retention of 98.4%after 1000 cycles.This work provides an alternative and simple strategy to realize the practical application of the solid-state SN-based polymer electrolyte.展开更多
Multicomponent metal sulfides have been recognized as promising anode materials for lithium/sodiumion storage given their enticing theoretical capacities. However, the simplification of synthetic processes and the con...Multicomponent metal sulfides have been recognized as promising anode materials for lithium/sodiumion storage given their enticing theoretical capacities. However, the simplification of synthetic processes and the construction of heterogeneous interfaces of multimetal sulfides remain great challenges. Herein,a hierarchical 1T-MoS2/carbon nanosheet decorated Co1–xS/N-doped carbon(Co1–xS/NC@MoS2/C) hollow nanofiber was designed and constructed via a one-pot hydrothermal method using a cobalt-based coordination polymer nanofiber. This nanofiber can transform in-situ into conductive N-doped carbon hollow fibers embedded with active Co1–xS nanoparticles, enabling the epitaxial growth of MoS2 nanosheets.Consequently, the Co1–xS/NC@MoS2/C composites achieve exceptional lithium/sodium-ion storage performance. Compared to MoS2/C microspheres and Co1–xS/NC hollow nanofibers alone, the Co1–xS/NC@MoS2/C hollow nanofibers deliver higher discharge capacities(1085.9 mAh g^-1 for lithium-ion batteries(LIBs) and 748.5 mAh g^-1 for sodium-ion batteries(SIBs) at 100 mA g^-1), better capacity retention(910 mAh g^-1 for LIBs and 636.5 mAh g^-1 for SIBs after 150 cycles at 100 mA g^-1), and increased cycling stability(407.2 mAh g^-1 after 1000 cycles for SIBs at 1000 m A g^-1). Furthermore, the kinetic analysis shows that the lithium/sodium-ion storage processes of the Co1–xS/NC@MoS2/C electrode are mainly controlled by pseudocapacitance behavior. The excellent electrochemical properties can thus be ascribed to the synergy of the MoS2/C nanosheets with the enlarged interlayer spacing, good conductivity of the carbon layers, and the Co1–xS nanoparticles embedded in the hollow nanofibers with extensive reaction sites.展开更多
L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FeP...L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe,Pt-containing bimetallic complex.The resultant L10-FePt NPs had very high crystallinity as reflected by the obvious diffractionpatterns,clear lattice fringes and characteristic X-ray diffraction peaks,etc.Besides,the strong ferromagnetism with room temperaturecoercivity of 27 kOe further confirmed the face-centered tetrag on al(fet)phase in good agreement with the ordered nano structures.TheFePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction(ORR)in an O2·saturated 0.1 M HClO4 solution andhydrogen evolution reaction(HER)in the 0.5 M H2SO4 electrolyte with much better performance than commercial Pt/C,and showedquite high stability after 10,000 cycles.The strategy utilizing orga no metallic precursors to prepare metal alloy NPs was dem on strated tobe a reliable approach for improving the catalytic efficiency in fuel cells.展开更多
Developing highly efficient oxygen evolution reaction(OER)catalyst for the acidic corrosive operating conditions is a challenging task.Herein,we report the synthesis of uniform RuO_(2)clusters with~2 nm in size via el...Developing highly efficient oxygen evolution reaction(OER)catalyst for the acidic corrosive operating conditions is a challenging task.Herein,we report the synthesis of uniform RuO_(2)clusters with~2 nm in size via electrochemical leaching of Sr from SrRuO_(3) ceramic in acid.The RuO_(2)clusters exhibit ultrahigh OER activity with overpotential of~160 mV at 10 mA·cm_(geo)^(−2) in 1.0 M HClO4 solution for 30-h testing.The extended X-ray absorption fine structure measurement reveals enlarged Jahn-Teller distortion of Ru-O octahedra in the RuO_(2)clusters compared to its bulk counterpart.Density function theory calculations show that the enhanced Jahn-Teller distortion can improve the intrinsic OER activity of RuO_(2).展开更多
Chirality,which is one of the defining features of biological molecules,plays a critical role in many important life processes.Controlled supramolecular assembly of biomolecules into functional structures with low str...Chirality,which is one of the defining features of biological molecules,plays a critical role in many important life processes.Controlled supramolecular assembly of biomolecules into functional structures with low structural fluidity,e.g.,cytoske-leton filaments[1],flagellar filaments of bacteria[2],and high structural fluidity(e.g.,cell membranes[3]),serves key roles in the correct functioning of biological processes.Inspired by natural supramolecular assembly,a large number of discrete two-and three-dimensional chiral polygons with well-defined shapes have been successfully prepared through self-assembly[4-8].展开更多
Utilizing vacuum-tuned-atmosphere induced dip coating method,we achieve the cross-dimensional macroscopic diverse self-assemblies by using one building block with one chemical functionality.Coordinated modulating the ...Utilizing vacuum-tuned-atmosphere induced dip coating method,we achieve the cross-dimensional macroscopic diverse self-assemblies by using one building block with one chemical functionality.Coordinated modulating the vacuum degree,colloid concentration and evaporation atmosphere,Au@Ag core/shell nanocubes (NCs) can controllably assemble into diverse multi-dimensional superstructures.Under 0.08 MPa,we obtained the two-dimensional (2D) stepped superstructures with continuously tunable step width.In addition,we generated a series of tailorable nanoscale-roughened 2D Au@Ag NCs superstructures at 0.04 MPa,which exhibited the label-free ultrasensitive SERS detection for the different mutants of IAPP8-37 proteins.Under 0.01 MPa,we obtained the cross-dimensional tailorable Au@Ag NCs assemblies from random to macroscale 2D and three-dimensional (3D) densest superstructures by adjusting the capping ligand-environmental molecule interactions.This is a flexible method to generate as-prepared Au@Ag core/shell NCs into well-defined macroscopic diverse superstructures and to promote the exploitation into biological applications.展开更多
Molecular motions of the luminescent liquid crystals(LLCs)show a significant effect on fluorescent emission and heat generation.In this article,a series of cyanostilbene-based LLCs(CSs:CS1-6,CS1-12,CS2-6 and CS2-12)ar...Molecular motions of the luminescent liquid crystals(LLCs)show a significant effect on fluorescent emission and heat generation.In this article,a series of cyanostilbene-based LLCs(CSs:CS1-6,CS1-12,CS2-6 and CS2-12)are synthesized to investigate how the pho-toluminescence and photothermal effect balanced.Among these materials,the mesogens peripheried by single alkyl chains formed enantiotropic nematic(CS1-6)or smectic C(CS1-12)phase with different alkyl tail lengths.When the single aliphatic chain is re-placed by mini-dendrons,room temperature(RT)monotropic hexagonal columnar phase(CS2-12)or molecular liquid(CS2-6)is formed.The results revealed that all these materials exhibited high efficiency emission with the highest quantum yield reaching 59.0%.The photoluminescence and photothermal effect can be effectively tuned by dispersing CSs into a commercially available RT liquid crystal matrix 8CB,which output significantly improved photothermal conversion efficiency of 63.2%.Furthermore,the pho-tothermal can rapidly trigger the Smectic A-Nematic-Isotropic sequence transitions of 8CB doped with CSs.This work paves a way of adjusting the balance of photoluminescence and photothermal properties of the LLC materials.展开更多
With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon mater...With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon materials with ultrahigh sensitivity,especially in a large pressure range regime are highly required in wearable applications.In this work,graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-drying(SAAD)method.In the SAAD process,air-drying the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained membranes.Owing to the excellent mechanical and electrical properties of graphene,the pressure sensor constructed by several layers of membranes exhibits high sensitivity(52.36 kPa……-1)and repeatability(short response and recovery time)in the loading pressure range of 0–50 kPa.Compared with most reported graphene-related pressure sensors,our device shows better sensitivity and wider applied pressure range.What’s more,we demonstrate it shows desired results in wearable applications for pulse monitoring,breathing detection as well as different intense motion recording such as walk,run and squat.It’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.展开更多
The development of high-performance glucose sensors is an urgent need, especially for diabetes mellitus diagnosis. However, the glucose monitoring is conventionally operated in an invasive finger-prick manner and thei...The development of high-performance glucose sensors is an urgent need, especially for diabetes mellitus diagnosis. However, the glucose monitoring is conventionally operated in an invasive finger-prick manner and their noninvasive alternatives largely suffered from the relatively poor sensitivity, selectivity, and stability, resulted from the lack of robust and efficient catalysts. In this paper, we design a concave shaped nitrogen-doped carbon framework embellished with single Co site catalyst(Co SSC) by selectively controlling the etching rate on different facet of carbon substrate, which is beneficial to the diffusion and contact of analyte. The Co SSC prompts a significant improvement in the sensitivity of the solutiongated graphene transistor(SGGT) devices, with three orders of magnitude better than those of SGGT devices without catalysts. Our findings expand the field of single site catalyst in the application of biosensors, diabetes diagnostics and personalized health-care monitoring.展开更多
This study aims to disclose the thermo-oxidative degradation behaviors and kinetics of a carbon fiber reinforced polyimide(CFRPI)composite for modeling of the Iong-term degradation process.The degradation behaviors we...This study aims to disclose the thermo-oxidative degradation behaviors and kinetics of a carbon fiber reinforced polyimide(CFRPI)composite for modeling of the Iong-term degradation process.The degradation behaviors were revealed through off-gas products analysis,and the overall kinetic interpretation was achieved from study of the mass-loss curves recorded under dynamic conditions.It was found that thermooxidative degradati on of the CFRPI composite was a multistep process,which in eluded four main reaction steps.Since most kinetic an alysis methods were derived from simple reactions described by a single kinetic triplet,they cannot be applied reliably to such a process.Therefore,we firstly separated the four overlapped reaction steps by peak fitting of derivative thermogravimetric curves using Fraser-Suzuki equation consider!ng the asymmetrical n ature of kin etic curves,and subsequently an a lyzed each in dividual reaction employing Friedma n method and experimental master-plots method.Four sets of kinetic triplets were determined to characterize the entire degradation process.The validity of four corresponding kinetic triplets was confirmed by perfect simulation of mass-loss curves recorded at both dynamic conditions used in kinetic analysis and entirely different isothermal conditions.Finally,modeling of Iong-term aging at 400°C of the CFRPI composite was successfully achieved based on these kinetic triplets.The predicted mass loss and flexural property correlated well with experimental results.This study can serve as a basis for rapid evaluation of the long-term durability of the CFRPI composite in various application environments.展开更多
Due to the enhanced electrochemical activities,mixed metal oxides offer new and fascinating opportunities for high-performance supercapacitor electrodes.However,sluggish ionic and electronic kinetics within the electr...Due to the enhanced electrochemical activities,mixed metal oxides offer new and fascinating opportunities for high-performance supercapacitor electrodes.However,sluggish ionic and electronic kinetics within the electrode fundamentally limit further improvement of their electrochemical performance.To compensate for the deficiency,a flexible electrode(CNTF/Ni-Co-Mn-Mo NS/CNTN)composed of vertically-aligned areolate quaternary metal oxide nanosheets sandwiched between carbon nanotubes(CNTs)is constructed in this study,which demonstrates a unique hierarchical porous structure that can provide three-dimensional transport channels for both ions and electrons.The vertically aligned areolate quaternary metal oxide nanosheets enable increased exposed surface area and paths for ion transport,diffusion and redox reactions,resulting in an evident enhancement in electrochemical activities.Besides,the CNT networks provide improved conductivity,which can accelerate the electron transport.As a result,the flexible supercapacitor based on the CNTF/Ni-Co-Mn-Mo NS/CNTN electrode demonstrates a specific areal capacitance of 3738 m F cm^-2,corresponding to a high energy density of 1.17 m W h cm^-2,which outperforms most of the flexible devices reported recently.Additionally,excellent flexibility of up to 180°bend and superior performance stability of 87.87%capacitance retention after 10,000 charge-discharge cycles can be obtained.This unique design opens up a new way in the development of flexible energy storage devices with high performance.展开更多
The rational fabrication of highly efficient electrocatalysts with low cost toward oxygen evolution reaction(OER)is greatly desired but remains a formidable challenge.In this work,we present a facile and straightforwa...The rational fabrication of highly efficient electrocatalysts with low cost toward oxygen evolution reaction(OER)is greatly desired but remains a formidable challenge.In this work,we present a facile and straightforward method of incorporating NiCo-layered double hydroxide(NiCo-LDH)into GO-dispersed CNTs(GO-CNTs)with interconnected configuration.X-ray absorption spectroscopy(XAS)reveals the strong electron interaction between NiCo-LDH and the underlying GO-CNTs substrate,which is supposed to facilitate charge transfer and accelerate the kinetics for OER.By tuning the amount of CNTs,the optimized NiCo-LDH/GO-CNTs composite can achieve a low overpotential of 290 mV at 10 mA·cm^(−2) current density,a small Tafel slope of 66.8 mV·dec^(−1) and robust stability,superior to the pure NiCo-LDH and commercial RuO_(2) in alkaline media.The preeminent oxygen evolution performance is attributed to the synergistic effect stemming from the merits and the intimate electron interaction between LDH and GO-CNTs.This allows NiCo-LDH/GO-CNTs to be potentially applied in an industrial non-noble metal-based water electrolyzer as the anodic catalysts.展开更多
Hydrogen energy is considered as an ideal energy with the advantages of green,sustainability,and high energy density,and water splitting is one of the efficient strategies for green hydrogen without carbon emission.As...Hydrogen energy is considered as an ideal energy with the advantages of green,sustainability,and high energy density,and water splitting is one of the efficient strategies for green hydrogen without carbon emission.As for cathodic hydrogen evolution reaction(HER),besides the Pt-based electrocatalysts with excellent electrocatalytic activities on HER,transition metal nitrides(TMNs)as cheap and facile-prepared electrocatalysts have shown remarkable electrocatalytic activities.Incorporation of N atom in metal interstitial lattice results in the unique structure of TMN with high electronic conductivity,strong chemical stability,and d-band contraction.Although the intrinsic electrocatalytic activities of TMNs are mostly lower than those of Pt,it also attracted much attention to the development of TMN with higher intrinsic activity by electronic structure modulation.Here,we review the recent improvement strategies for the intrinsic electrocatalytic activities of TMN catalysts on HER by electronic structure modulation,such as facet,alloying,doping,vacancy,heterostructure,and hybridization.Some important breakthroughs of TMNs have been made;however,the scale application of TMNs with high activity in commercial water electrolyzer is urgent to explore.The future development of TMNs is proposed to focus on developing facile synthesis methods,elucidating regulation mechanism and catalytic mechanism,and enhancing activity and stability.展开更多
Because of the intensified electrochemical activities,mixed metal oxides as a representative for pseudocapacitive materials play a key role for high performance supercapacitor electrodes.Nevertheless,low ion and elect...Because of the intensified electrochemical activities,mixed metal oxides as a representative for pseudocapacitive materials play a key role for high performance supercapacitor electrodes.Nevertheless,low ion and electron transfer rate and poor cycling performance in the electrode practically restrict further promotion of their electrochemical performance.In order to offset the defect,a novel copper(Cu)foamsupported nickel molybdate nanosheet decorated carbon nanotube wrapped copper oxide nanowire array(NiMoO4 NSs-CNTs-CuO NWAs/Cu foam)flexible electrode is constructed.The as-prepared electrode demonstrates a unique core-shell holey nanostructure with a large active surface area,which can provide a large number of active sites for redox reactions.Besides,the CNTs networks supply improved conductivity,which can hasten electron transport.Through this simple and efficient design method,the spatial distribution of each component in the flexible electrode is more orderly,short and fast electron transport path with low intrinsic resistance.As a result,the NiMoO4 NSs-CNTs-CuO NWAs/Cu foam as an adhesiveless supercapacitor electrode material exhibits excellent ene rgy storage perfo rmance with high specific areal capacitance of 23.40 F cm^(-2)at a current density of 2 mA cm^(-2),which outperforms most of the flexible electrodes re ported recently.The assembled asymmetric supercapacitor demonstrates an energy density up to 96.40 mW h cm^(-3)and a power density up to 0.4 W cm^(-3)under a working voltage window of 1.7 V.In addition,outstanding flexibility of up to 100°bend and good cycling stability with the capacitance retention of 82.53%after 10,000 cycles can be obtained.展开更多
Why many luminescent liquid crystalline polymers(LLCPs)containing aggregation-induced emission luminogen(AIEgen)show weak emission is a question still to be answered.Herein,a series of LLCPs(α-Pns,n=4,8,and 12)with p...Why many luminescent liquid crystalline polymers(LLCPs)containing aggregation-induced emission luminogen(AIEgen)show weak emission is a question still to be answered.Herein,a series of LLCPs(α-Pns,n=4,8,and 12)with polynorbornene as main chain and twoα-dicyanodistyrylbenzene(α-DCS)as side chain are successfully synthesized to solve this issue.Differential scanning calorimetry(DSC),polarized light microscopy(PLM),one-dimentional(1D),two-dimentional(2D)middle-angle and wide-angle X-ray scattering(MAXS and WAXS)results demonstrate that the polymers form smectic A(SmA)phase with the side chains interdigitated packed within the smectic layers.Meanwhile,the photophysical properties ofα-Pns were investigated by ultraviolet-visible(UV-vis)absorption,steady state and time-resolved spectroscopy,and photothermal effect.Results show that the polymers are AIE active,but emit weak emission.The emission peak ofα-Pns film red-shift from 473 to 531 nm,the quantum yield gradually increases from around 1.6%to 14.7%,and the photothermal conversion efficiency decreases from 39%to 19%with the alkyl tail length increased.The photothermal effect,but not photoluminescence,dominates the excited state relaxation.展开更多
基金Guangdong Basic and Applied Basic Research Foundation(2021A1515110152,2022A1515240007,and 2023A1515010562)Special Fund for the Sci-tech Innovation Strategy of Guangdong Province(STKJ202209083,STKJ202209066,2020ST006,210719165864287)+4 种基金Characteristic Innovation Project of Colleges and Universities in Guangdong(2021KTSCX030)Scientific Research Foundation of Guangdong Laboratory of Chemistry and Fine Chemical Industry Jieyang Center(QD2221007)2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(2020LKSFG01A)STU Scientific Research Initiation Grant(NTF20005,NTF22018)Science and technology program of Guangzhou(202102021110).
文摘Photothermal conversion attracted lots of attention in the past years and sorts of materials were explored to enhance photothermal efficiency.In the past years,solar-driven desalination by photothermal conversion was proposed to release the shortage of fresh water and then it was considered much more important to prepare photothermal materials on large scales with high performance and low cost.In this review,we summarized the works on carbon-based photothermal materials in the past years,including the preparation as well as their application in steam generation.From these works,we give an outlook on the difficulties and chances of how to design and prepare carbon-based photothermal materials.
基金financially supported by the National Natural Science Foundation of China (Nos.51973118, 22175121,52003160 and 22001175)Key-Area Research and Development Program of Guangdong Province (Nos.2019B010941001 and2019B010929002)+7 种基金the Natural Science Foundation of Guangdong Province (No.2020A1515010644)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08C642)Shenzhen Science and Technology Program (Nos.JCYJ20220818095810022, JSGGZD20220822095201003 and JCYJ20210324095412035)the start-up fund of Shenzhen University (No.000002110820)the Guangdong Natural Science Foundation (Nos.2022A1515011781 and2021A1515110086)Science and Technology Innovation Commission of Shenzhen,China (Nos.RCBS20200714114910141 and JCYJ20210324132816039)the Start-up Grant at Harbin Institute of Technology (Shenzhen),China (Nos.HA45001108 and HA11409049)Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application (No.ZDSYS20220527171407017)。
文摘The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.
基金financially supported by the National Natural Science Foundation of China(No.52303010)Key-Area Research and Development Program of Guangdong province(No.2019B010941001)+2 种基金Key Technology of Liquid Crystal Polymer Material for 5G/6G High Frequency Communication(No.JSGGZD20220822095201003)Songshan Lake Materials Laboratory(No.2021SLABFK01)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110143)。
文摘The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer media.Traditionally,it has been theorized that rigid molecular chains lead to lower dielectric loss.However,the validity of this proposition at high frequencies remains uncertain.To scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic ring.The introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry conditions.The dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)conditions.Furthermore,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic nature.Molecular simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water molecules.Despite sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality films.Our research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.
基金This work was supported by China Ministry of Science and Technology(No.2021YFA1500404)the Anhui Provincial Natural Science Foundation(Nos.2108085QB70 and 2108085UD06)+4 种基金the DNL Cooperation Fund,CAS(No.DNL201918)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2021HSC-CIP002)the Natural Science Foundation of Hefei,China(No.2021044)the Fundamental Research Funds for the Central Universities(Nos.WK2060000004,WK2060000021,WK2060000025,KY2060000180,and KY2060000195)the Fundamental Research Funds for the Central Universities(No.WK5290000003)。
文摘Single atom catalysts have been recognized as potential catalysts to fabricate electrochemical biosensors,due to their unexpected catalytic selectivity and activity.Here,we designed and fabricated an ultrasensitive dopamine(DA)sensor based on the flower-like MoS_(2) embellished with single Ni site catalyst(Ni-MoS_(2)).The limit of detection could achieve 1 pM in phosphate buffer solution(PBS,pH=7.4),1 pM in bovine serum(pH=7.4),and 100 pM in artificial urine(pH=6.8).The excellent sensing performance was attributed to the Ni single atom axial anchoring on the Mo atom in the MoS_(2) basal plane with the Ni-S_(3) structure.Both the experiment and density functional theory(DFT)results certify that this structural feature is more favorable for the adsorption and electron transfer of DA on Ni atoms.The high proportion of Ni active sites on MoS_(2) basal plane effectively enhanced the intrinsic electronic conductivity and electrochemical activity toward DA.The successful establishment of this sensor gives a new guide to expand the field of single atom catalyst in the application of biosensors.
基金financially supported by the National Natural Science Foundation of China(Nos.22001175,51973118,22175121 and 52003160)Key-Area Research and Development Program of Guangdong Province(Nos.2019B010929002 and 2019B010941001)+3 种基金the Natural Science Foundation of Guangdong Province(No.2020A1515010644)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08C642)Shenzhen Science and Technology Program(Nos.JCYJ20210324095412035,JCYJ20190808113005643,JCYJ20170818093832350 and JCYJ20180507184711069)the start-up fund of Shenzhen University(No.000002110820)。
文摘Artificial soft actuators,featured with non-equilibrium internal circumstance and fast,programmable shape transformations,have attracted strong research interest recently due to their flexibility,highly controllable,and designability.However,wireless soft actuators,achieving the locomotion on different large slopes with multiple energy conversion,have been rarely reported.Herein,we create a asymmetric bilayer strategy to construct autonomous soft crawler via“breathing”moisture to motivate the mechanical deformation.The soft crawlers present conspicuous performances including periodic tumbler locomotion predicted via improved Timoshenko’s equation,multiple reversible shape-morphing(circle,helix,despiralization,etc.)determined by their fiber orientation,controlled drive mode(front drive and rear drive)and rapid climb speed(4.76 cm/min)at wide slope angles.Through architecture design,they can be series-wound or shunt-wound to construct multijoint complex actuators.Besides climbing,a intelligent soft ring-pull with admirable cycle performance for preventing overheating or something untouchable,has been proposed.The soft crawlers also realize multiple energy conversion to be actuated by light irradiation.We envision that this soft crawler system has an enormous potential in intelligent machine,microscopic diagnosis and treatment,biosensing,energy harvesting and conversion.
基金the National Natural Science Foundation of China(Nos.52003160 and 51973118)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010644)+2 种基金Key-Area Research and Development Program of Guangdong Province(Nos.2019B010929002 and 2019B010941001)the Science and Technology Innovation Commission of Shenzhen(No.JCYJ20190808150001775)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08C642)。
文摘Quasi solid-state succinonitrile(SN)-based polymer electrolytes have emerged for lithium-metal batteries due to their excellent ionconductivity at room temperature,wide electrochemical stability window(ESW,usually>5 V).However,the practical application of these solid SN-based polymer electrolytes is hampered by the flammability and the inherent instability of SN to Li-metal anode.In this work,solid SN-based polymer electrolytes were prepared with succinonitrile,ethoxylated trimethylolpropane triacrylate(ETPTA),triethyl phosphate(TEP)and fluoroethylene carbonate for Li-metal battery via in situ polymerization method.The SN-based polymer electrolytes with 5 wt%triethyl phosphate and FEC showed good nonflammability,superior ion-conductivity as high as 1.01×10^(-3)S/cm,and wide ESW of 5.41 V.This SN-based polymer electrolyte also exhibited excellent interfacial compatibility to lithium metal anode.And it also delivered a high specific capacity of 156m Ah/g at 0.2 C at ambient temperature,and presented stable cycling at 1.0 C with a specific capacity retention of 98.4%after 1000 cycles.This work provides an alternative and simple strategy to realize the practical application of the solid-state SN-based polymer electrolyte.
基金This work was supported by the National Natural Science Foundation of China(51673117,21805193 and 51973118)Postdoctoral Science Foundation of China(2019M650212)+2 种基金Key R&D Program of Guangdong Province(2019B010929002 and 2019B010941001)Science and Technology Innovation Commission of Shenzhen(JCYJ20170817094628397,JCYJ20170818093832350,JCYJ20170818112409808,JCYJ20170818100112531,JCYJ20180507184711069,and JCYJ20180305125319991)The authors also thank the Materials and Devices Testing Center of Tsinghua University Shenzhen Graduate School.
文摘Multicomponent metal sulfides have been recognized as promising anode materials for lithium/sodiumion storage given their enticing theoretical capacities. However, the simplification of synthetic processes and the construction of heterogeneous interfaces of multimetal sulfides remain great challenges. Herein,a hierarchical 1T-MoS2/carbon nanosheet decorated Co1–xS/N-doped carbon(Co1–xS/NC@MoS2/C) hollow nanofiber was designed and constructed via a one-pot hydrothermal method using a cobalt-based coordination polymer nanofiber. This nanofiber can transform in-situ into conductive N-doped carbon hollow fibers embedded with active Co1–xS nanoparticles, enabling the epitaxial growth of MoS2 nanosheets.Consequently, the Co1–xS/NC@MoS2/C composites achieve exceptional lithium/sodium-ion storage performance. Compared to MoS2/C microspheres and Co1–xS/NC hollow nanofibers alone, the Co1–xS/NC@MoS2/C hollow nanofibers deliver higher discharge capacities(1085.9 mAh g^-1 for lithium-ion batteries(LIBs) and 748.5 mAh g^-1 for sodium-ion batteries(SIBs) at 100 mA g^-1), better capacity retention(910 mAh g^-1 for LIBs and 636.5 mAh g^-1 for SIBs after 150 cycles at 100 mA g^-1), and increased cycling stability(407.2 mAh g^-1 after 1000 cycles for SIBs at 1000 m A g^-1). Furthermore, the kinetic analysis shows that the lithium/sodium-ion storage processes of the Co1–xS/NC@MoS2/C electrode are mainly controlled by pseudocapacitance behavior. The excellent electrochemical properties can thus be ascribed to the synergy of the MoS2/C nanosheets with the enlarged interlayer spacing, good conductivity of the carbon layers, and the Co1–xS nanoparticles embedded in the hollow nanofibers with extensive reaction sites.
基金This work was supported by the National Natural Science Foundation of China(No.21701112)Science,Technology and Innovation Committee of Shenzhen Municipality(No.JCYJ20170303160036674)+2 种基金Hong Kong Research Grants Council(PolyU153062/18R C4006-17G and HKUST16304117)the Hong Kong Polytechnic University(1-ZE1C)Ms Clarea Au(847S)for the Endowed Professorship in Energy.Special thanks were also given to Instrumental Analysis Center of Shenzhen University(Xili Campus).
文摘L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe,Pt-containing bimetallic complex.The resultant L10-FePt NPs had very high crystallinity as reflected by the obvious diffractionpatterns,clear lattice fringes and characteristic X-ray diffraction peaks,etc.Besides,the strong ferromagnetism with room temperaturecoercivity of 27 kOe further confirmed the face-centered tetrag on al(fet)phase in good agreement with the ordered nano structures.TheFePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction(ORR)in an O2·saturated 0.1 M HClO4 solution andhydrogen evolution reaction(HER)in the 0.5 M H2SO4 electrolyte with much better performance than commercial Pt/C,and showedquite high stability after 10,000 cycles.The strategy utilizing orga no metallic precursors to prepare metal alloy NPs was dem on strated tobe a reliable approach for improving the catalytic efficiency in fuel cells.
基金the National Natural Science Foundation of China(Nos.22022508,51602143 and 11874036)Guangdong Natural Science Foundation for Distinguished Young Scholars(No.2016A030306020)the National Key Research and Development Program of China(No.2017YFB0701600)。
文摘Developing highly efficient oxygen evolution reaction(OER)catalyst for the acidic corrosive operating conditions is a challenging task.Herein,we report the synthesis of uniform RuO_(2)clusters with~2 nm in size via electrochemical leaching of Sr from SrRuO_(3) ceramic in acid.The RuO_(2)clusters exhibit ultrahigh OER activity with overpotential of~160 mV at 10 mA·cm_(geo)^(−2) in 1.0 M HClO4 solution for 30-h testing.The extended X-ray absorption fine structure measurement reveals enlarged Jahn-Teller distortion of Ru-O octahedra in the RuO_(2)clusters compared to its bulk counterpart.Density function theory calculations show that the enhanced Jahn-Teller distortion can improve the intrinsic OER activity of RuO_(2).
基金supported by the National Natural Science Foundation of China (21875143 and 21908146)the Innovation Research Foundation of Shenzhen (JCYJ20180507182229597)the Natural Science Foundation of Guangdong Province (2016A030312002)。
文摘Chirality,which is one of the defining features of biological molecules,plays a critical role in many important life processes.Controlled supramolecular assembly of biomolecules into functional structures with low structural fluidity,e.g.,cytoske-leton filaments[1],flagellar filaments of bacteria[2],and high structural fluidity(e.g.,cell membranes[3]),serves key roles in the correct functioning of biological processes.Inspired by natural supramolecular assembly,a large number of discrete two-and three-dimensional chiral polygons with well-defined shapes have been successfully prepared through self-assembly[4-8].
基金the National Natural Science Foundation of China (Nos.51872030,51631001,21643003,51702016,and 51501010)Fundamental Research Funds for the Central Universities and Beijing Institute of Technology Research Fund Program for Young Scholars and ZDKT18-01 fund from State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology).We acknowledge critical and quantity of testing work supported by Beijing Zhongkebaice Technology Service Co., Ltd.
文摘Utilizing vacuum-tuned-atmosphere induced dip coating method,we achieve the cross-dimensional macroscopic diverse self-assemblies by using one building block with one chemical functionality.Coordinated modulating the vacuum degree,colloid concentration and evaporation atmosphere,Au@Ag core/shell nanocubes (NCs) can controllably assemble into diverse multi-dimensional superstructures.Under 0.08 MPa,we obtained the two-dimensional (2D) stepped superstructures with continuously tunable step width.In addition,we generated a series of tailorable nanoscale-roughened 2D Au@Ag NCs superstructures at 0.04 MPa,which exhibited the label-free ultrasensitive SERS detection for the different mutants of IAPP8-37 proteins.Under 0.01 MPa,we obtained the cross-dimensional tailorable Au@Ag NCs assemblies from random to macroscale 2D and three-dimensional (3D) densest superstructures by adjusting the capping ligand-environmental molecule interactions.This is a flexible method to generate as-prepared Au@Ag core/shell NCs into well-defined macroscopic diverse superstructures and to promote the exploitation into biological applications.
基金supported bythe National Natural ScienceFoundation of China(Nos.21875143and21875157)the InnovationResearch Foundationof Shenzhen(No.JCYJ20180507182229597)the Natural Science Foundation of Guangdong Province(No.2016-A030312002)and theopen foundation of State Key Laboraatory of Chemical Engineering(No.SKL ChE-20B04).
文摘Molecular motions of the luminescent liquid crystals(LLCs)show a significant effect on fluorescent emission and heat generation.In this article,a series of cyanostilbene-based LLCs(CSs:CS1-6,CS1-12,CS2-6 and CS2-12)are synthesized to investigate how the pho-toluminescence and photothermal effect balanced.Among these materials,the mesogens peripheried by single alkyl chains formed enantiotropic nematic(CS1-6)or smectic C(CS1-12)phase with different alkyl tail lengths.When the single aliphatic chain is re-placed by mini-dendrons,room temperature(RT)monotropic hexagonal columnar phase(CS2-12)or molecular liquid(CS2-6)is formed.The results revealed that all these materials exhibited high efficiency emission with the highest quantum yield reaching 59.0%.The photoluminescence and photothermal effect can be effectively tuned by dispersing CSs into a commercially available RT liquid crystal matrix 8CB,which output significantly improved photothermal conversion efficiency of 63.2%.Furthermore,the pho-tothermal can rapidly trigger the Smectic A-Nematic-Isotropic sequence transitions of 8CB doped with CSs.This work paves a way of adjusting the balance of photoluminescence and photothermal properties of the LLC materials.
基金Financial support from the grant from the City University of Hong Kong(SRG 7004918)South China University of Technology(National Key Research and Development Program of China,No.2016YFB0302000)Shenzhen University(Ten Thousand People’s Scheme,Project No.201,810,090,052)。
文摘With the prosperous development of artificial intelligence,medical diagnosis and electronic skins,wearable electronic devices have drawn much attention in our daily life.Flexible pressure sensors based on carbon materials with ultrahigh sensitivity,especially in a large pressure range regime are highly required in wearable applications.In this work,graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-drying(SAAD)method.In the SAAD process,air-drying the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained membranes.Owing to the excellent mechanical and electrical properties of graphene,the pressure sensor constructed by several layers of membranes exhibits high sensitivity(52.36 kPa……-1)and repeatability(short response and recovery time)in the loading pressure range of 0–50 kPa.Compared with most reported graphene-related pressure sensors,our device shows better sensitivity and wider applied pressure range.What’s more,we demonstrate it shows desired results in wearable applications for pulse monitoring,breathing detection as well as different intense motion recording such as walk,run and squat.It’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.
基金supported by the Postdoctoral Science Foundation of China (2019M653052)the Fundamental Research Funds for the Central Universities (WK2060120002)+1 种基金the National Key R&D Program of China (2017YFA, 0208300)the National Natural Science Foundation of China (21671180)。
文摘The development of high-performance glucose sensors is an urgent need, especially for diabetes mellitus diagnosis. However, the glucose monitoring is conventionally operated in an invasive finger-prick manner and their noninvasive alternatives largely suffered from the relatively poor sensitivity, selectivity, and stability, resulted from the lack of robust and efficient catalysts. In this paper, we design a concave shaped nitrogen-doped carbon framework embellished with single Co site catalyst(Co SSC) by selectively controlling the etching rate on different facet of carbon substrate, which is beneficial to the diffusion and contact of analyte. The Co SSC prompts a significant improvement in the sensitivity of the solutiongated graphene transistor(SGGT) devices, with three orders of magnitude better than those of SGGT devices without catalysts. Our findings expand the field of single site catalyst in the application of biosensors, diabetes diagnostics and personalized health-care monitoring.
文摘This study aims to disclose the thermo-oxidative degradation behaviors and kinetics of a carbon fiber reinforced polyimide(CFRPI)composite for modeling of the Iong-term degradation process.The degradation behaviors were revealed through off-gas products analysis,and the overall kinetic interpretation was achieved from study of the mass-loss curves recorded under dynamic conditions.It was found that thermooxidative degradati on of the CFRPI composite was a multistep process,which in eluded four main reaction steps.Since most kinetic an alysis methods were derived from simple reactions described by a single kinetic triplet,they cannot be applied reliably to such a process.Therefore,we firstly separated the four overlapped reaction steps by peak fitting of derivative thermogravimetric curves using Fraser-Suzuki equation consider!ng the asymmetrical n ature of kin etic curves,and subsequently an a lyzed each in dividual reaction employing Friedma n method and experimental master-plots method.Four sets of kinetic triplets were determined to characterize the entire degradation process.The validity of four corresponding kinetic triplets was confirmed by perfect simulation of mass-loss curves recorded at both dynamic conditions used in kinetic analysis and entirely different isothermal conditions.Finally,modeling of Iong-term aging at 400°C of the CFRPI composite was successfully achieved based on these kinetic triplets.The predicted mass loss and flexural property correlated well with experimental results.This study can serve as a basis for rapid evaluation of the long-term durability of the CFRPI composite in various application environments.
基金supported by the National Natural Science Foundation of China(51673117 and 21805193)the Science and Technology Innovation Commission of Shenzhen(JSGG20160226201833790,JCYJ20170818093832350,JCYJ20170818112409808 and JSGG20170824112840518)China Postdoctoral Science Foundation(2017M622786,2017M622787 and 2019M653067)。
文摘Due to the enhanced electrochemical activities,mixed metal oxides offer new and fascinating opportunities for high-performance supercapacitor electrodes.However,sluggish ionic and electronic kinetics within the electrode fundamentally limit further improvement of their electrochemical performance.To compensate for the deficiency,a flexible electrode(CNTF/Ni-Co-Mn-Mo NS/CNTN)composed of vertically-aligned areolate quaternary metal oxide nanosheets sandwiched between carbon nanotubes(CNTs)is constructed in this study,which demonstrates a unique hierarchical porous structure that can provide three-dimensional transport channels for both ions and electrons.The vertically aligned areolate quaternary metal oxide nanosheets enable increased exposed surface area and paths for ion transport,diffusion and redox reactions,resulting in an evident enhancement in electrochemical activities.Besides,the CNT networks provide improved conductivity,which can accelerate the electron transport.As a result,the flexible supercapacitor based on the CNTF/Ni-Co-Mn-Mo NS/CNTN electrode demonstrates a specific areal capacitance of 3738 m F cm^-2,corresponding to a high energy density of 1.17 m W h cm^-2,which outperforms most of the flexible devices reported recently.Additionally,excellent flexibility of up to 180°bend and superior performance stability of 87.87%capacitance retention after 10,000 charge-discharge cycles can be obtained.This unique design opens up a new way in the development of flexible energy storage devices with high performance.
基金This work was supported by Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)the National Major Science and Technology Program for Water Pollution Control and Treatment of China(No.2017ZX07202)。
文摘The rational fabrication of highly efficient electrocatalysts with low cost toward oxygen evolution reaction(OER)is greatly desired but remains a formidable challenge.In this work,we present a facile and straightforward method of incorporating NiCo-layered double hydroxide(NiCo-LDH)into GO-dispersed CNTs(GO-CNTs)with interconnected configuration.X-ray absorption spectroscopy(XAS)reveals the strong electron interaction between NiCo-LDH and the underlying GO-CNTs substrate,which is supposed to facilitate charge transfer and accelerate the kinetics for OER.By tuning the amount of CNTs,the optimized NiCo-LDH/GO-CNTs composite can achieve a low overpotential of 290 mV at 10 mA·cm^(−2) current density,a small Tafel slope of 66.8 mV·dec^(−1) and robust stability,superior to the pure NiCo-LDH and commercial RuO_(2) in alkaline media.The preeminent oxygen evolution performance is attributed to the synergistic effect stemming from the merits and the intimate electron interaction between LDH and GO-CNTs.This allows NiCo-LDH/GO-CNTs to be potentially applied in an industrial non-noble metal-based water electrolyzer as the anodic catalysts.
基金This work was supported by the National Natural Science Foundation of China(52101251)Natural Science Foun-dation of Hebei Province(B2021208030)+1 种基金College Students Inno-vation Training Program of Hebei Province(S2021113409001)STU Scientific Research Initiation Grant(NTF22018).Author contributions:J.S.,M.J.,and C.Z.led the project.The manuscript was primarily written by H.-M.Z.,and J.-J.W.,Y.M.,F.L.,and J.X.revised it.All authors contributed to the manu-script.Competing interests:The authors declare that they have no competing interests.
文摘Hydrogen energy is considered as an ideal energy with the advantages of green,sustainability,and high energy density,and water splitting is one of the efficient strategies for green hydrogen without carbon emission.As for cathodic hydrogen evolution reaction(HER),besides the Pt-based electrocatalysts with excellent electrocatalytic activities on HER,transition metal nitrides(TMNs)as cheap and facile-prepared electrocatalysts have shown remarkable electrocatalytic activities.Incorporation of N atom in metal interstitial lattice results in the unique structure of TMN with high electronic conductivity,strong chemical stability,and d-band contraction.Although the intrinsic electrocatalytic activities of TMNs are mostly lower than those of Pt,it also attracted much attention to the development of TMN with higher intrinsic activity by electronic structure modulation.Here,we review the recent improvement strategies for the intrinsic electrocatalytic activities of TMN catalysts on HER by electronic structure modulation,such as facet,alloying,doping,vacancy,heterostructure,and hybridization.Some important breakthroughs of TMNs have been made;however,the scale application of TMNs with high activity in commercial water electrolyzer is urgent to explore.The future development of TMNs is proposed to focus on developing facile synthesis methods,elucidating regulation mechanism and catalytic mechanism,and enhancing activity and stability.
基金supported by the National Natural Science Foundation of China(Nos.51673117,51973118,and 21805193)the Science and Technology Innovation Commission of Shenzhen(Nos.JCYJ20170818093832350,JCYJ20170818112409808,JSGG20170824112840518,JCYJ20180507184711069,JCYJ20170818100112531,JCYJ20170817094628397,and JCYJ20180305125319991)+1 种基金the Key-Area Research and Development Program of Guangdong Province(Nos.2019B010929002 and 2019B010941001)the China Postdoctoral Science Foundation(No.2019M650212)。
文摘Because of the intensified electrochemical activities,mixed metal oxides as a representative for pseudocapacitive materials play a key role for high performance supercapacitor electrodes.Nevertheless,low ion and electron transfer rate and poor cycling performance in the electrode practically restrict further promotion of their electrochemical performance.In order to offset the defect,a novel copper(Cu)foamsupported nickel molybdate nanosheet decorated carbon nanotube wrapped copper oxide nanowire array(NiMoO4 NSs-CNTs-CuO NWAs/Cu foam)flexible electrode is constructed.The as-prepared electrode demonstrates a unique core-shell holey nanostructure with a large active surface area,which can provide a large number of active sites for redox reactions.Besides,the CNTs networks supply improved conductivity,which can hasten electron transport.Through this simple and efficient design method,the spatial distribution of each component in the flexible electrode is more orderly,short and fast electron transport path with low intrinsic resistance.As a result,the NiMoO4 NSs-CNTs-CuO NWAs/Cu foam as an adhesiveless supercapacitor electrode material exhibits excellent ene rgy storage perfo rmance with high specific areal capacitance of 23.40 F cm^(-2)at a current density of 2 mA cm^(-2),which outperforms most of the flexible electrodes re ported recently.The assembled asymmetric supercapacitor demonstrates an energy density up to 96.40 mW h cm^(-3)and a power density up to 0.4 W cm^(-3)under a working voltage window of 1.7 V.In addition,outstanding flexibility of up to 100°bend and good cycling stability with the capacitance retention of 82.53%after 10,000 cycles can be obtained.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.21875143,21674065,and 21975215)the Innovation Research Foundation of Shenzhen(Nos.SGG20190222175202275,JCYJ20180507182229597,and JCYJ20180305125649693)the Natural Science Foundation of Guangdong Province(No.2016A030312002)。
文摘Why many luminescent liquid crystalline polymers(LLCPs)containing aggregation-induced emission luminogen(AIEgen)show weak emission is a question still to be answered.Herein,a series of LLCPs(α-Pns,n=4,8,and 12)with polynorbornene as main chain and twoα-dicyanodistyrylbenzene(α-DCS)as side chain are successfully synthesized to solve this issue.Differential scanning calorimetry(DSC),polarized light microscopy(PLM),one-dimentional(1D),two-dimentional(2D)middle-angle and wide-angle X-ray scattering(MAXS and WAXS)results demonstrate that the polymers form smectic A(SmA)phase with the side chains interdigitated packed within the smectic layers.Meanwhile,the photophysical properties ofα-Pns were investigated by ultraviolet-visible(UV-vis)absorption,steady state and time-resolved spectroscopy,and photothermal effect.Results show that the polymers are AIE active,but emit weak emission.The emission peak ofα-Pns film red-shift from 473 to 531 nm,the quantum yield gradually increases from around 1.6%to 14.7%,and the photothermal conversion efficiency decreases from 39%to 19%with the alkyl tail length increased.The photothermal effect,but not photoluminescence,dominates the excited state relaxation.
