High energy density and low cost make lithium-sulfur(Li-S)batteries as one of the next generation's promising energy storage systems.However,the following problems need to be solved before commercialization:(i)the...High energy density and low cost make lithium-sulfur(Li-S)batteries as one of the next generation's promising energy storage systems.However,the following problems need to be solved before commercialization:(i)the shuttling effect and sluggish redox kinetics of lithium polysulfides in sulfur cathode;(ii)the formation of lithium dendrites and the crack of solid electrolyte interphase;(iii)the large volume changes during charge and discharge processes.MXenes,as newly emerging two-dimensional transition metal carbides/nitrides/carbonitrides,have attracted widespread attention due to their abundant active surface terminals,adjustable vacancies,and high electrical conductivity.Designing MXene-based heterogeneous structures is expected to solve the stacking problem induced by hydrogen bonds or Van der Waals force and to provide other charming physiochemical properties.Herein,we generalize the design principles of MXene-based heterostructures and their functions,i.e.,adsorption and catalysis in advanced conversion-based Li-S batteries.Firstly,the physiochemical properties of MXene and MXene-based heterostructures are briefly introduced.Secondly,the catalytic functions of MXene-based heterostructures with the compositional constituents including carbon materials,metal compounds,organic frameworks,polymers,single atoms and special high-entropy MXenes are comprehensively summarized in sulfur cathodes and lithium anodes.Finally,the challenges of MXene-based heterostructure in current Li-S batteries are pointed out and we also provide some enlightenments for future developments in high-energy-density Li-S batteries.展开更多
In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototra...In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototransistor is fabricated and measured,integrating a TiO_(2)nanolayer gate and a two-dimensional electron gas(2DEG)channel to mimic the synaptic weight and the synaptic cleft,respectively.The maximum drain to source current is 10 nA,while the device is driven at a reverse bias not exceeding-2.5 V.A excitatory postsynaptic current(EPSC)of 200 nA can be triggered by a 365 nm UVA light spike with the duration of 1 s at light intensity of 1.35μW·cm^(-2).Multiple synaptic neuromorphic functions,including EPSC,short-term/long-term plasticity(STP/LTP)and paried-pulse facilitation(PPF),are effectively mimicked by our GaN-based het-erostructure synaptic device.In the typical Pavlov’s dog experiment,we demonstrate that the device can achieve"retraining"process to extend memory time through enhancing the intensity of synaptic weight,which is similar to the working mecha-nism of human brain.展开更多
This study aims to achieve a synergy of strength and ductility in magnesium-based nanocomposite materials through the design of a dual-heterostructure. Utilizing ball milling and hot extrusion, a nano-TiC/AZ61 composi...This study aims to achieve a synergy of strength and ductility in magnesium-based nanocomposite materials through the design of a dual-heterostructure. Utilizing ball milling and hot extrusion, a nano-TiC/AZ61 composite featuring particle-rare coarse grain (CG) and particle-rich fine grain (FG) zones was successfully fabricated. Experimental results demonstrated that compared with the homogeneous structure, the dual-heterostructure composite achieved a significant increase in elongation by 116 % and a remarkable 165 % improvement in the strength-ductility product (SDP), while maintaining a high ultimate tensile strength (UTS) of 417±4 MPa. This substantial performance enhancement is primarily attributed to the additional strain hardening induced by hetero-deformation-induced (HDI) strain hardening and crack-blunting capabilities, as elucidated by microstructural characterization and crystal plasticity finite element modeling (CPFEM). Notably, the strain hardening contribution from the CG zones at the early stage of deformation (≤ 45 % of total plastic deformation amount) is minimal but increases significantly during the subsequent deformation stages. The dislocation increment rate in CG zones (219 %) is observed to be more than double that in FG zones (95 %), attributed to the large grain size and low dislocation density in CG zones, which provide more space for dislocation storage. In addition, the aggravated deformation inhomogeneity as deformation progresses leads to an increase in geometrically necessary dislocations (GNDs) generation near the heterogeneous interface, thereby enhancing HDI hardening. Fracture mechanism analysis indicated that the cracks mainly initiate in the FG region and are effectively blunted upon their propagation to the CG region, necessitating increased energy consumption and indicating higher fracture toughness for the dual-heterostructure composites. This study validates the effectiveness of the dual-heterostructure design in magnesium-based composites, providing a novel understanding of the deformation mechanism through both experimental analysis and CPFEM, paving the way for the development of high-performance, lightweight structural materials.展开更多
Although phase-change random-access memory(PCRAM)is a promising next-generation nonvolatile memory technology,challenges remain in terms of reducing energy consumption.This is primarily be-cause the high thermal condu...Although phase-change random-access memory(PCRAM)is a promising next-generation nonvolatile memory technology,challenges remain in terms of reducing energy consumption.This is primarily be-cause the high thermal conductivities of phase-change materials(PCMs)promote Joule heating dissi-pation.Repeated phase transitions also induce long-range atomic diffusion,limiting the durability.To address these challenges,phase-change heterostructure(PCH)devices that incorporate confinement sub-layers based on transition-metal dichalcogenide materials have been developed.In this study,we engi-neered a PCH device by integrating HfTe_(2),which has low thermal conductivity and excellent stability,into the PCM to realize PCRAM with enhanced thermal efficiency and structural stability.HEAT sim-ulations were conducted to validate the superior heat confinement in the programming region of the HfTe_(2)-based PCH device.Moreover,electrical measurements of the device demonstrated its outstanding performance,which was characterized by a low RESET current(∼1.6 mA),stable two-order ON/OFF ratio,and exceptional cycling endurance(∼2×10^(7)).The structural integrity of the HfTe_(2)confinement sub-layer was confirmed using X-ray photoelectron spectroscopy and transmission electron microscopy.The material properties,including electrical conductivity,cohesive energy,and electronegativity,substantiated these findings.Collectively,these results revealed that the HfTe_(2)-based PCH device can achieve significant improvements in performance and reliability compared with conventional PCRAM devices.展开更多
Transition metal dichalcogenides(TMDs)recently attracted widespread attention due to their potential application to the electrocatalysis of the hydrogen evolution reaction(HER).However,their HER performance is far inf...Transition metal dichalcogenides(TMDs)recently attracted widespread attention due to their potential application to the electrocatalysis of the hydrogen evolution reaction(HER).However,their HER performance is far inferior to that of platinum(Pt)metal.Preparation of multi-elemental alloy and construction of heterostructure are considered as highly effective methods to enhance hydrogen production activity.Herein,a novel quaternary CoMoSSe alloy with heterostructure was synthesized on the surface of carbon black(CB)particles(CoMoSSe@CB)by a simple Sol-Gel process and thereafter served as HER catalyst.Compared to CoSe@CB and MoS2@CB electrocatalysts,CoMoSSe@CB exhibits superior HER activity with a low overpotential of 190 mV at-10 mA·cm^(-2) and a Tafel slope of 62 mV·dec^(-1).This improvement is attributed to the alloying effects among Co,Mo,S and Se,as well as the heterogeneous structure in the composite material,which regulate the electronic structure and intermediate free energy,thereby increasing the number of active sites and enhancing charge-transfer ability.This work can provide new ideas and concepts for designing novel and efficient TMD electrocatalysts.展开更多
The growing need for flexible and wearable electronics,such as smartwatches and foldable displays,highlights the shortcomings of traditional energy storage methods.In response,scientists are developing compact,flexibl...The growing need for flexible and wearable electronics,such as smartwatches and foldable displays,highlights the shortcomings of traditional energy storage methods.In response,scientists are developing compact,flexible,and foldable energy devices to overcome these challenges.MXenes-a family of twodimensional nanomaterials-are a promising solution because of their unique properties,including a large surface area,excellent electrical conductivity,numerous functional groups,and distinctive layered structures.These attributes make MXenes attractive options for flexible energy storage.This paper reviews recent advances in using flexible MXene-based materials for flexible Li−S batteries,metal-ion batteries(Zn and Na),and supercapacitors.The development of MXene-based composites is explored,with a detailed electrochemical performance analysis of various flexible devices.The review addresses significant challenges and outlines strategic objectives for advancing robust and flexible MXene-based energy storage devices.展开更多
In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide r...In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide radiation quantum energy range of 0.62–3.1 eV both at T=4.2 K and at T=77 K.Common features of the PPC spectra for all structures were revealed,and their relation to the presence of a CdTe cap layer in all structures and the appropriate cadmium fraction in the CdHgTe barrier layers was shown.One of the features was associated with the presence of a deep level in the CdTe layer.In addition,the oscillatory behavior of the PPC spectra in the region from 0.8–1.1 eV to 1.2–1.5 eV was observed.It is associated with the cascade emission of longitudinal optical phonons in CdHgTe barrier.展开更多
Metal-organic frameworks(MOFs)have been considered as great contender and promising electrode materials for supercapacitors.However,their low capacity,aggregation,and poor porosity have necessitated the exploration of...Metal-organic frameworks(MOFs)have been considered as great contender and promising electrode materials for supercapacitors.However,their low capacity,aggregation,and poor porosity have necessitated the exploration of new approaches to enhance the performance of these active materials.In this study,sphere-like MOF were in-situ grown and it subsequently burst,transformed into a desired metal oxide heterostructure comprising n-type ZnO and p-type NiO(ZnO/NiO-350).The resulting optimized flower-like structure,composed of interlaced nanoflakes derived from MOFs,greatly improved the active sites,porosity,and functionality of the electrode materials.The ZnO/NiO-350 electrode exhibited superior electrochemical activities for supercapacitors,compared to the parent MOF,bare n-type,and p-type counterparts.The specific capacitance can reach to 543 F g^(-1) at a current density of 1 A g^(-1).Theoretical modeling and simulations were employed to gain insights into the atomic-scale properties of the materials.Furthermore,an assembled hybrid device using active carbon and ZnO/NiO-350 as electrodes demonstrated excellent energy density of 44 Wh kg^(-1) at a power density of 1.6 Kw kg^(-1).After 5000 cycles at 10 A g^(-1),the cycling stability remained excellent 80%of the initial capacitance.Overall,such evaluation of unique electrode with superior properties may be useful for the next generation supercapacitor electrode.展开更多
Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostruct...Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostructure composed of platinum and molybdenum carbide(Pt@Mo_(2)C)derived from polyoxometalate clusters is designed to achieve excellent alkaline hydrogen evolution reaction.The Pt@Mo_(2)C cluster exhibits strong electronic interactions between Pt and Mo_(2)C,working together to facilitate the H_(2)O dissociation by concurrently binding intermediates(Pt-H*and Mo-OH*),thus accelerating the kinetics of the rate-determining Volmer step.Theoptimized Pt@Mo_(2)C exhibits a high mass activity of12.1 A·mgpt^(-1),19.2 times higher than that of 20%Pt/C in alkaline media.Moreover,it can be stabilized at a current density of 100 mA·cm^(-2)for more than 200 h.This work demonstrated the superiority of the cluster heterostructures and co-catalytic effect towards the development of highly efficient electrocatalysts.展开更多
Nanostructure engineering and composition rationalization are crucial for materials to become candidates for high-performance supercapacitor.Herein,a novel core-shell heterostructured electrode,combining CoS hollow na...Nanostructure engineering and composition rationalization are crucial for materials to become candidates for high-performance supercapacitor.Herein,a novel core-shell heterostructured electrode,combining CoS hollow nanorods with NiCoMn-layered double hydroxides(LDH)ternary metal nanosheets,were prepared on carbon cloth by reasonably controlled vulcanization and electrodeposition.By optimizing electrodeposition conditions,the material's structure and properties can be fine-tuned.The enhanced capacitance of the optimized carbon cloth(CC)@CoS/NiCoMn-LDH-300 electrode(4256.0 F g^(-1))lies in the open space provided by CoS and the establishment of a new charge transfer channel across the interfaces of CC@CoS/NiCoMn-LDH-300 nanosheets.This is further demonstrated by Density functional theory(DFT)simulations based on OHadsorption energy,which produces faster redox charge kinetics and significantly enhances the electrode's energy storage capacity.The hybrid supercapacitor,integrating the optimized CC@CoS/NiCoMn-LDH-300 electrode with active carbon,demonstrates the highest energy density of 86 Wh kg^(-1)(under the power density of 850 W kg^(-1))and the long cycle stability of 89.7%.This study aims to go beyond simple binary LDH by constructing a ternary LDH with a hierarchical core-shell heterostructure to provide an effective and feasible new concept for high-performance supercapacitor electrode materials via rational structure design.展开更多
Rechargeable magnesium batteries(RMBs)have garnered significant attention in energy storage applications due to their high capacity,low cost,and high safety.However,the strong polarization effect and slow kinetic de-i...Rechargeable magnesium batteries(RMBs)have garnered significant attention in energy storage applications due to their high capacity,low cost,and high safety.However,the strong polarization effect and slow kinetic de-intercalation of Mg^(2+)in the cathode limit their commercial application.This study presents a novel interface-coupled V_(2)CT_(x)@VS_(4)heterostructure through a one-step hydrothermal process.In this architecture,V_(2)CT_(x)and VS_(4)can mutually support their structural framework,which effectively prevents the structural collapse of V_(2)CT_(x)MXene and the aggregation of VS_(4).Crucially,interfacial coupling between V_(2)CT_(x)and VS_(4)induces strong V-S bonds,substantially enhancing structural stability.Benefiting from these advantages,the heterostructure exhibits high specific capacity(226 mAh g^(-1)at 100 mA g^(-1))and excellent long-cycle stability(89% capacity retention after 1000 cycles at 500 mA g^(-1)).Furthermore,the Mg^(2+)storage mechanism in the V_(2)CT_(x)@VS_(4)composite was elucidated through a series of ex-situ characterizations.This work provides a feasible strategy for designing V_(2)CT_(x)MXene-based cathodes with high capacity and extended cyclability for RMBs.展开更多
Transition metal selenides(TMSs),as promising anode materials for sodium ion batteries(SIBs),still face sluggish Na+diffusion kinetics and severe volume change,resulting in undesirable cycling stability and rate capab...Transition metal selenides(TMSs),as promising anode materials for sodium ion batteries(SIBs),still face sluggish Na+diffusion kinetics and severe volume change,resulting in undesirable cycling stability and rate capability.Heterostructure construction is an effective method to improve sodium ion storage in TMSs.Herein,a hierarchical hollow heterostructure of CoSe_(2)@SnSe is precisely designed through a facile coprecipitation process followed by a selenization strategy.The heterostructure constructed by CoSe_(2)and SnSe nanocrystals induces the formation of built-in electric fields and accelerates electron transfer and ion diffusion,thereby improving reaction kinetics significantly.When the as-prepared CoSe_(2)@SnSe composites are employed as anode materials of SIBs,there exhibit ultra-fast electrochemical reaction kinetics and outstanding cycling stability with a high capacity retention of 488.9 mAh g^(-1)at a current density of 2.0 A g^(-1)after 900 cycles.In addition,there still shows an exceptional rate capability of 409.5 mAh g^(-1)at a high current density of 10 A g^(-1).This work provides an effective method for the rational designing of heterostructure anode materials for high-performance SIBs.展开更多
Lithium sulfide(Li_(2)S)is widely regarded as the next-generation cathode material for rechargeable batteries due to its satisfactory theoretical capacity and excellent compatibility with lithium-free anodes.However,t...Lithium sulfide(Li_(2)S)is widely regarded as the next-generation cathode material for rechargeable batteries due to its satisfactory theoretical capacity and excellent compatibility with lithium-free anodes.However,the large-scale applications of Li_(2)S cathodes are limited by the shuttle effect of soluble intermediate lithium polysulfides(LiPSs)and the sluggish redox kinetics of the interconversion between Li_(2)S and sulfur(S).Herein,we report novel nitrogen-doped carbon nanoflakes in-situ embedded with WN-Ni_(2)P heterostructures(WN-Ni_(2)P@NCN)as a multifunctional host to promote the cycling performance and reaction kinetics of Li_(2)S.After loading Li_(2)S,the WNNi_(2)P@NCN/Li_(2)S exhibits stable reversible capacity of 597mAh g^(-1)at 0.5 A g^(-1)over 150 cycles,and superior cycling stability over 800 cycles.The high reversible capacities,excellent cycling properties and superior reaction kinetics of WN-Ni_(2)P@NCN/Li_(2)S are attributed to the strong LiPSs fixation,remarkable catalytic activation and high electronic/ionic conductivity of the WN-Ni_(2)P@NCN framework,confirmed by the experiment and the density function theory calculation results.This work offers a new strategy for designing heterostructure nanoflakes with metal nitride and metal phosphide to facilitate the applications of advanced lithium-sulfur batteries.展开更多
Nickel-based alloys applied in marine environments often face multiple challenges of stress,corrosion and wear.In this work,heterostructured NiCrTi alloy was prepared by spark plasma sintering coarse Ni20Cr and ultraf...Nickel-based alloys applied in marine environments often face multiple challenges of stress,corrosion and wear.In this work,heterostructured NiCrTi alloy was prepared by spark plasma sintering coarse Ni20Cr and ultrafine Ti powders.Apart that some are dissolved into the nickel alloy,Ti powders react in situ with Ni20Cr during sintering to form hard intermetallic Ni_(3)Ti.It builds up a typical heterostructure that endows NiCrTi alloy with well-balanced mechanical strength and plasticity,e.g.high yield strength of 1321 MPa,compressive strength of 2470 MPa,and compressive strain of 20%.On tribocorrosion,the hard shell enriched with Ti transforms to connected protrusion and form in situ surface texture.Oxides or wear debris are trapped at the textured surface and compacted to form a stable tribofilm.Thus negative synergy between corrosion and wear is observed for NiCrTi and high tribocorrosion resistance is achieved.At a potential of+0.3 V,the tribocorrosion rate of NiCrTi is reduced by an order of magnitude to 1.87×10^(-5)mm^(3)/(Nm)in comparison to the alloy Ni20Cr.展开更多
The heterostructure preparation in Mg-rare earth(RE)alloy has attracted much attention due to the excellent enhancement of strength and ductility.However,the effect of heterostructure composition on mechanical propert...The heterostructure preparation in Mg-rare earth(RE)alloy has attracted much attention due to the excellent enhancement of strength and ductility.However,the effect of heterostructure composition on mechanical properties in Mg-RE alloy is still not clear.In this work,three types of heterostructures with different composition induced by lamellar 14H long period stacking ordered(LPSO)phase were achieved in the Mg-Gd-Y-Zn-Zr alloys after cyclic extrusion and compression(CEC).The heterostructure was mainly composed of dynamic recrystallization(DRX)grains,deformed coarse grains,multiscale LPSO phase(blocky,granular,lamellar LPSO phase).The strength and ductility of Mg-Gd-Y-Zn-Zr alloy with heterostructure were simultaneously improved.The DRX behavior during CEC process was largely affected by the lamellar LPSO phase.The lamellar LPSO with large spacing(∼92 nm)and low thickness(∼13.46 nm)is easy to occur kinking behavior and the zigzag kinking area can serve as nucleation sites to promote DRX behavior.While the lamellar LPSO phase with high thickness(∼23.41 nm)and similar spacing(∼82 nm)was ruptured into granular LPSO phase and thus increase the volume fraction of granular LPSO phase,which made a great contribution to DRX behavior by particle stimulated nucleation.The main deformation mechanism of solution treatment+furnace cooling(SF)sample during CEC process is dominated by the multiple slips composed of basal slips,prismatic slips and pyramidal slips.For the solution treatment+air cooling(SA)sample and solution treatment+ageing treatment(ST)sample,the activation of basal slips is the critical deformation mechanism.The main contribution to yield strength is from the grain boundary,dislocation and hetero-deformation induced(HDI)strengthening.Moreover,the HDI strengthening in the SF and SA sample after CEC deformation is much larger than that of ST sample due to the distinct heterostructure composition.展开更多
In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitr...In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported.Selenization temperature plays a significant role in determining the phases,morphology,and lithium-ion storage performance of the composite.Notably,the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g,surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C-or ZnSe@C-based anodes.Furthermore,ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite.展开更多
Heterostructured materials as a new class can effectively avoid the inverted relationship of the“banana”curve followed by strength-ductility.The difference in grain size is the mainstream idea of the design of heter...Heterostructured materials as a new class can effectively avoid the inverted relationship of the“banana”curve followed by strength-ductility.The difference in grain size is the mainstream idea of the design of heterogeneous zones.However,the synergistic strengthening mechanism and deformation behavior among multi-scale heterostructures are still unclear.In this work,AZ80/AZ31 laminate with a multi-scale heterogeneous distribution of grain size,precipitates,and texture between alternate AZ31 and AZ80 component layers,which was constructed by accumulative extrusion bonding combined with aging treatment.The composite samples after 2-pass extrusion presented an outstanding strength-ductility synergy,which was attributed to the joint action of texture softening and hardening,grain refinement as well as multistage heterogeneous deformation induced(HDI)strengthening and hardening.Multi-types of heterogeneous regions provided more sites for geometrically necessary dislocation accumulation to accommodate multiple strain gradients under the constraint of multi-layer interfaces,enhancing HDI stress.The synergistic effect of great Schmid factor difference and increasing geometric compatibility factor between adjacent grains at the layer interface led to strain transfer behavior,which facilitated strain delocalization.This work expands the design ideas and preparation methods of heterostructured materials and enriches the theory of heterogeneous deformation.展开更多
Creating strongly coupled heterostructures with favorable catalytic activities is crucial for promoting the performance of catalytic reactions,especially those involve multiple intermediates.Herein,we fabricated a str...Creating strongly coupled heterostructures with favorable catalytic activities is crucial for promoting the performance of catalytic reactions,especially those involve multiple intermediates.Herein,we fabricated a strongly coupled platinum/molybdenum nitrides nanocluster heterostructure on nitrogen-doped reduced graphene oxide(Pt/Mo_(2)N-NrGO)for alkaline hydrogen evolution reaction.The well-defined Pt-containing Anderson-type polyoxometalates promote strong interfacial Pt-N-Mo bonding in Pt/Mo_(2)N-NrGO,which exhibits a remarkably low overpotential,high mass activity,and exceptional long-term durability(>500 h at 1500 mA cm^(-2))in an anion-exchange membrane water electrolyzer(AEMWE).Operando Raman spectroscopy and density functional theory reveal that pronounced electronic coupling at the Pt/Mo_(2)N cluster interface facilitates the catalytic decomposition of H_(2)O through synergistic stabilization of intermediates(Pt-H^(*)and Mo-OH^(*)),thereby enhancing the kinetics of the rate-determining Volmer step.Techno-economic analysis indicates a levelized hydrogen production cost of$2.02 kg^(-1),meeting the US DOE targets.Our strategy presents a viable pathway to designing next-generation catalysts for industrial AEMWE for green hydrogen production.展开更多
The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathod...The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathode material with a p-n heterostructure of polyaniline(PANI)/ZnS is prepared to trap visible light,utilizing a ZnS quantum dot(ZnS QD)network to form a large number of photogenerated electron–hole pairs,thus promoting the generation and decomposition of Li_(2)O_(2).The prepared PANI/ZnS has an ultra-low overpotential of 0.06 V under illumination.Furthermore,density functional theory theoretical calculation has demonstrated the ability of the heterostructures to adsorb oxygen-containing intermediates,which not only facilitates the growth of Li_(2)O_(2),but also reduces the reaction energy required to decompose Li_(2)O_(2).The present work provides a solution to the problem of insolubility of discharge products in photo-assisted LOB.展开更多
The heterostructures incorporated with two or more distinctive two-dimensional(2D)materials have attracted great attention be-cause they could give rise to enhanced prop-erty in comparison with their individual counte...The heterostructures incorporated with two or more distinctive two-dimensional(2D)materials have attracted great attention be-cause they could give rise to enhanced prop-erty in comparison with their individual counterparts.Here,a water-assisted two-step rapid physical vapor deposition(rPVD)method was explored and used to synthesize Bi_(2)Te_(3)-Sb_(2)Te_(3)lateral het-erostructures(LHS)successfully.The Bi_(2)Te_(3)-Sb_(2)Te_(3)LHS is in nearly uniform size,and grows along three particular orientations with the intersection angles of 120°.Inter-estingly,we found that the water molecules play a significant role in determining the growth orientation,namely whether it will grow along the vertical or lateral direction in 2D structure.Hence,a growth mechanism of LHS based on the water-assisted two-step rPVD was present,which can be used as a general strategy and extended to the growth of other 2D heterostruc-tures or homostructures,such as SnS-SnSe LHS and SnS-SnS lateral homostructures.Fur-thermore,the second-harmonic generation intensity of the Bi_(2)Te_(3)-Sb_(2)Te_(3)LHS is much stronger than that of the Bi_(2)Te_(3)/Sb_(2)Te_(3)vertical heterostructures(VHS).This work opens a new approach for the synthesis of water-assisted lateral 2D heterostructures or homostruc-tures and offers a new method to enhance the second-harmonic generation properties of topo-logical insulating materials.展开更多
基金This work was financially supported by the National Key R&D Program(No.2021YFA1201503)the National Natural Science Foundation of China(Nos.22075081,21972164,and 22279161)+1 种基金the Fundamental Research Funds for the Central Universities(No.JKD01231701)the Natural Science Foundation of Jiangsu Province(No.BK 20210130).
文摘High energy density and low cost make lithium-sulfur(Li-S)batteries as one of the next generation's promising energy storage systems.However,the following problems need to be solved before commercialization:(i)the shuttling effect and sluggish redox kinetics of lithium polysulfides in sulfur cathode;(ii)the formation of lithium dendrites and the crack of solid electrolyte interphase;(iii)the large volume changes during charge and discharge processes.MXenes,as newly emerging two-dimensional transition metal carbides/nitrides/carbonitrides,have attracted widespread attention due to their abundant active surface terminals,adjustable vacancies,and high electrical conductivity.Designing MXene-based heterogeneous structures is expected to solve the stacking problem induced by hydrogen bonds or Van der Waals force and to provide other charming physiochemical properties.Herein,we generalize the design principles of MXene-based heterostructures and their functions,i.e.,adsorption and catalysis in advanced conversion-based Li-S batteries.Firstly,the physiochemical properties of MXene and MXene-based heterostructures are briefly introduced.Secondly,the catalytic functions of MXene-based heterostructures with the compositional constituents including carbon materials,metal compounds,organic frameworks,polymers,single atoms and special high-entropy MXenes are comprehensively summarized in sulfur cathodes and lithium anodes.Finally,the challenges of MXene-based heterostructure in current Li-S batteries are pointed out and we also provide some enlightenments for future developments in high-energy-density Li-S batteries.
基金supported by the National Key R&D Program of China(2021YFB3601000,2021YFB3601004)the National Key R&D Program of China(2022YFB3604702)the Chinese Academy of Sciences.
文摘In recent years,research focusing on synaptic device based on phototransistors has provided a new method for asso-ciative learning and neuromorphic computing.A TiO_(2)/AlGaN/GaN heterostructure-based synaptic phototransistor is fabricated and measured,integrating a TiO_(2)nanolayer gate and a two-dimensional electron gas(2DEG)channel to mimic the synaptic weight and the synaptic cleft,respectively.The maximum drain to source current is 10 nA,while the device is driven at a reverse bias not exceeding-2.5 V.A excitatory postsynaptic current(EPSC)of 200 nA can be triggered by a 365 nm UVA light spike with the duration of 1 s at light intensity of 1.35μW·cm^(-2).Multiple synaptic neuromorphic functions,including EPSC,short-term/long-term plasticity(STP/LTP)and paried-pulse facilitation(PPF),are effectively mimicked by our GaN-based het-erostructure synaptic device.In the typical Pavlov’s dog experiment,we demonstrate that the device can achieve"retraining"process to extend memory time through enhancing the intensity of synaptic weight,which is similar to the working mecha-nism of human brain.
基金support from the China Scholarship Council(No.202107000038)support from the National Natural Science Foundation of China(Nos.52004227,52061040,and 12222209)the China Postdoctoral Science Foundation(No:2021M692512).
文摘This study aims to achieve a synergy of strength and ductility in magnesium-based nanocomposite materials through the design of a dual-heterostructure. Utilizing ball milling and hot extrusion, a nano-TiC/AZ61 composite featuring particle-rare coarse grain (CG) and particle-rich fine grain (FG) zones was successfully fabricated. Experimental results demonstrated that compared with the homogeneous structure, the dual-heterostructure composite achieved a significant increase in elongation by 116 % and a remarkable 165 % improvement in the strength-ductility product (SDP), while maintaining a high ultimate tensile strength (UTS) of 417±4 MPa. This substantial performance enhancement is primarily attributed to the additional strain hardening induced by hetero-deformation-induced (HDI) strain hardening and crack-blunting capabilities, as elucidated by microstructural characterization and crystal plasticity finite element modeling (CPFEM). Notably, the strain hardening contribution from the CG zones at the early stage of deformation (≤ 45 % of total plastic deformation amount) is minimal but increases significantly during the subsequent deformation stages. The dislocation increment rate in CG zones (219 %) is observed to be more than double that in FG zones (95 %), attributed to the large grain size and low dislocation density in CG zones, which provide more space for dislocation storage. In addition, the aggravated deformation inhomogeneity as deformation progresses leads to an increase in geometrically necessary dislocations (GNDs) generation near the heterogeneous interface, thereby enhancing HDI hardening. Fracture mechanism analysis indicated that the cracks mainly initiate in the FG region and are effectively blunted upon their propagation to the CG region, necessitating increased energy consumption and indicating higher fracture toughness for the dual-heterostructure composites. This study validates the effectiveness of the dual-heterostructure design in magnesium-based composites, providing a novel understanding of the deformation mechanism through both experimental analysis and CPFEM, paving the way for the development of high-performance, lightweight structural materials.
基金financially supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(No.2016R1A3B1908249,RS202400407199).
文摘Although phase-change random-access memory(PCRAM)is a promising next-generation nonvolatile memory technology,challenges remain in terms of reducing energy consumption.This is primarily be-cause the high thermal conductivities of phase-change materials(PCMs)promote Joule heating dissi-pation.Repeated phase transitions also induce long-range atomic diffusion,limiting the durability.To address these challenges,phase-change heterostructure(PCH)devices that incorporate confinement sub-layers based on transition-metal dichalcogenide materials have been developed.In this study,we engi-neered a PCH device by integrating HfTe_(2),which has low thermal conductivity and excellent stability,into the PCM to realize PCRAM with enhanced thermal efficiency and structural stability.HEAT sim-ulations were conducted to validate the superior heat confinement in the programming region of the HfTe_(2)-based PCH device.Moreover,electrical measurements of the device demonstrated its outstanding performance,which was characterized by a low RESET current(∼1.6 mA),stable two-order ON/OFF ratio,and exceptional cycling endurance(∼2×10^(7)).The structural integrity of the HfTe_(2)confinement sub-layer was confirmed using X-ray photoelectron spectroscopy and transmission electron microscopy.The material properties,including electrical conductivity,cohesive energy,and electronegativity,substantiated these findings.Collectively,these results revealed that the HfTe_(2)-based PCH device can achieve significant improvements in performance and reliability compared with conventional PCRAM devices.
基金Scientific Research and Innovation Team Program of Sichuan University of Science and Engineering(SUSE652B004,2024RC13)Special Basic Cooperative Research Programs of Yunnan Provincial Undergraduate Universities Association(202101BA070001-085)。
文摘Transition metal dichalcogenides(TMDs)recently attracted widespread attention due to their potential application to the electrocatalysis of the hydrogen evolution reaction(HER).However,their HER performance is far inferior to that of platinum(Pt)metal.Preparation of multi-elemental alloy and construction of heterostructure are considered as highly effective methods to enhance hydrogen production activity.Herein,a novel quaternary CoMoSSe alloy with heterostructure was synthesized on the surface of carbon black(CB)particles(CoMoSSe@CB)by a simple Sol-Gel process and thereafter served as HER catalyst.Compared to CoSe@CB and MoS2@CB electrocatalysts,CoMoSSe@CB exhibits superior HER activity with a low overpotential of 190 mV at-10 mA·cm^(-2) and a Tafel slope of 62 mV·dec^(-1).This improvement is attributed to the alloying effects among Co,Mo,S and Se,as well as the heterogeneous structure in the composite material,which regulate the electronic structure and intermediate free energy,thereby increasing the number of active sites and enhancing charge-transfer ability.This work can provide new ideas and concepts for designing novel and efficient TMD electrocatalysts.
基金National Key Research and Development Program of China,Grant/Award Numbers:2021YFA0715600,2021YFA0717700.
文摘The growing need for flexible and wearable electronics,such as smartwatches and foldable displays,highlights the shortcomings of traditional energy storage methods.In response,scientists are developing compact,flexible,and foldable energy devices to overcome these challenges.MXenes-a family of twodimensional nanomaterials-are a promising solution because of their unique properties,including a large surface area,excellent electrical conductivity,numerous functional groups,and distinctive layered structures.These attributes make MXenes attractive options for flexible energy storage.This paper reviews recent advances in using flexible MXene-based materials for flexible Li−S batteries,metal-ion batteries(Zn and Na),and supercapacitors.The development of MXene-based composites is explored,with a detailed electrochemical performance analysis of various flexible devices.The review addresses significant challenges and outlines strategic objectives for advancing robust and flexible MXene-based energy storage devices.
基金supported by the Russian Science Foundation (Grant No. 22-12-00298)supported by the Center of Excellence "Center of Photonics" funded by the Ministry of Science and Higher Education of the Russian Federation, Contract #075-15-2022-316the Theoretical Physics and Mathematics Advancement Foundation "BASIS" scholarship for the support.
文摘In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide radiation quantum energy range of 0.62–3.1 eV both at T=4.2 K and at T=77 K.Common features of the PPC spectra for all structures were revealed,and their relation to the presence of a CdTe cap layer in all structures and the appropriate cadmium fraction in the CdHgTe barrier layers was shown.One of the features was associated with the presence of a deep level in the CdTe layer.In addition,the oscillatory behavior of the PPC spectra in the region from 0.8–1.1 eV to 1.2–1.5 eV was observed.It is associated with the cascade emission of longitudinal optical phonons in CdHgTe barrier.
基金supported by the Hong Kong Research Grants Council(No.CityU 11201522).
文摘Metal-organic frameworks(MOFs)have been considered as great contender and promising electrode materials for supercapacitors.However,their low capacity,aggregation,and poor porosity have necessitated the exploration of new approaches to enhance the performance of these active materials.In this study,sphere-like MOF were in-situ grown and it subsequently burst,transformed into a desired metal oxide heterostructure comprising n-type ZnO and p-type NiO(ZnO/NiO-350).The resulting optimized flower-like structure,composed of interlaced nanoflakes derived from MOFs,greatly improved the active sites,porosity,and functionality of the electrode materials.The ZnO/NiO-350 electrode exhibited superior electrochemical activities for supercapacitors,compared to the parent MOF,bare n-type,and p-type counterparts.The specific capacitance can reach to 543 F g^(-1) at a current density of 1 A g^(-1).Theoretical modeling and simulations were employed to gain insights into the atomic-scale properties of the materials.Furthermore,an assembled hybrid device using active carbon and ZnO/NiO-350 as electrodes demonstrated excellent energy density of 44 Wh kg^(-1) at a power density of 1.6 Kw kg^(-1).After 5000 cycles at 10 A g^(-1),the cycling stability remained excellent 80%of the initial capacitance.Overall,such evaluation of unique electrode with superior properties may be useful for the next generation supercapacitor electrode.
基金supported by the National Natural Science Foundation of China(Nos.22171287 and 52303274)Taishan Scholar Project of Shandong Province(No.tsqn202103046)+2 种基金Natural Science Foundation of Shandong Province(No.ZR2022QE175)Young Innovative Science and Technology Support Program for Universities of Shandong Province,P.R.China(Nos.2023KJ280 and 2021KJ014)Fundamental Research Funds for the Central Universities(Nos.24CX07007A and 22CX01002A-1)
文摘Constructing clus ter heterostructures with strongly coupled interfaces is of great importance to accelerating the catalytic reactions that involve multiple intermediates.Herein,a strongly coupled cluster heterostructure composed of platinum and molybdenum carbide(Pt@Mo_(2)C)derived from polyoxometalate clusters is designed to achieve excellent alkaline hydrogen evolution reaction.The Pt@Mo_(2)C cluster exhibits strong electronic interactions between Pt and Mo_(2)C,working together to facilitate the H_(2)O dissociation by concurrently binding intermediates(Pt-H*and Mo-OH*),thus accelerating the kinetics of the rate-determining Volmer step.Theoptimized Pt@Mo_(2)C exhibits a high mass activity of12.1 A·mgpt^(-1),19.2 times higher than that of 20%Pt/C in alkaline media.Moreover,it can be stabilized at a current density of 100 mA·cm^(-2)for more than 200 h.This work demonstrated the superiority of the cluster heterostructures and co-catalytic effect towards the development of highly efficient electrocatalysts.
基金supported by the National Natural Science Foundation of China(52203147)the Zhejiang Provincial Natural Science Foundation of China(LQ22B010006)+2 种基金the significant science and technology projects of LongMen Laboratory in Henan Province(231100221100)the significant science and technology projects of LongMen Laboratory in Henan Province(231100220100)the Key research and development program of Henan province(231111222200).
文摘Nanostructure engineering and composition rationalization are crucial for materials to become candidates for high-performance supercapacitor.Herein,a novel core-shell heterostructured electrode,combining CoS hollow nanorods with NiCoMn-layered double hydroxides(LDH)ternary metal nanosheets,were prepared on carbon cloth by reasonably controlled vulcanization and electrodeposition.By optimizing electrodeposition conditions,the material's structure and properties can be fine-tuned.The enhanced capacitance of the optimized carbon cloth(CC)@CoS/NiCoMn-LDH-300 electrode(4256.0 F g^(-1))lies in the open space provided by CoS and the establishment of a new charge transfer channel across the interfaces of CC@CoS/NiCoMn-LDH-300 nanosheets.This is further demonstrated by Density functional theory(DFT)simulations based on OHadsorption energy,which produces faster redox charge kinetics and significantly enhances the electrode's energy storage capacity.The hybrid supercapacitor,integrating the optimized CC@CoS/NiCoMn-LDH-300 electrode with active carbon,demonstrates the highest energy density of 86 Wh kg^(-1)(under the power density of 850 W kg^(-1))and the long cycle stability of 89.7%.This study aims to go beyond simple binary LDH by constructing a ternary LDH with a hierarchical core-shell heterostructure to provide an effective and feasible new concept for high-performance supercapacitor electrode materials via rational structure design.
基金Financial support from the National Natural Science Foundation of China(52302317)is gratefully acknowledged。
文摘Rechargeable magnesium batteries(RMBs)have garnered significant attention in energy storage applications due to their high capacity,low cost,and high safety.However,the strong polarization effect and slow kinetic de-intercalation of Mg^(2+)in the cathode limit their commercial application.This study presents a novel interface-coupled V_(2)CT_(x)@VS_(4)heterostructure through a one-step hydrothermal process.In this architecture,V_(2)CT_(x)and VS_(4)can mutually support their structural framework,which effectively prevents the structural collapse of V_(2)CT_(x)MXene and the aggregation of VS_(4).Crucially,interfacial coupling between V_(2)CT_(x)and VS_(4)induces strong V-S bonds,substantially enhancing structural stability.Benefiting from these advantages,the heterostructure exhibits high specific capacity(226 mAh g^(-1)at 100 mA g^(-1))and excellent long-cycle stability(89% capacity retention after 1000 cycles at 500 mA g^(-1)).Furthermore,the Mg^(2+)storage mechanism in the V_(2)CT_(x)@VS_(4)composite was elucidated through a series of ex-situ characterizations.This work provides a feasible strategy for designing V_(2)CT_(x)MXene-based cathodes with high capacity and extended cyclability for RMBs.
基金the financial support from the LiaoNing Revitalization Talents Program(Grant No.XLYC2403047)the National Natural Science Foundation of China(Grant No.22211530046)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.DUT23BK022DUT24YG212)the Yingkou Science and Technology Bureau,State Key Laboratory of New Textile Materials and Advanced Processing Technologies(Grant No.FZ2023009)。
文摘Transition metal selenides(TMSs),as promising anode materials for sodium ion batteries(SIBs),still face sluggish Na+diffusion kinetics and severe volume change,resulting in undesirable cycling stability and rate capability.Heterostructure construction is an effective method to improve sodium ion storage in TMSs.Herein,a hierarchical hollow heterostructure of CoSe_(2)@SnSe is precisely designed through a facile coprecipitation process followed by a selenization strategy.The heterostructure constructed by CoSe_(2)and SnSe nanocrystals induces the formation of built-in electric fields and accelerates electron transfer and ion diffusion,thereby improving reaction kinetics significantly.When the as-prepared CoSe_(2)@SnSe composites are employed as anode materials of SIBs,there exhibit ultra-fast electrochemical reaction kinetics and outstanding cycling stability with a high capacity retention of 488.9 mAh g^(-1)at a current density of 2.0 A g^(-1)after 900 cycles.In addition,there still shows an exceptional rate capability of 409.5 mAh g^(-1)at a high current density of 10 A g^(-1).This work provides an effective method for the rational designing of heterostructure anode materials for high-performance SIBs.
基金financially supported by the National Key R&D Program of China(No.2022YFB2502000)the National Natural Science Foundation of China(Nos.51902079,52072342,52377216 and 52102324)+3 种基金Anhui Provincial Natural Science Foundation(Nos.2008085QE271 and 2208085ME108)Excellent Research and Innovation Team of Anhui Universities(No.2022AH010096)Natural Science Research Project for Anhui Universities(No.2024AH051519)Hefei Institutes of Physical Science,Chinese Academy of Sciences Director's Fund(Nos.BJPY2023B04,YZJJ-GGZX-2022-01 and YZJJ202102)
文摘Lithium sulfide(Li_(2)S)is widely regarded as the next-generation cathode material for rechargeable batteries due to its satisfactory theoretical capacity and excellent compatibility with lithium-free anodes.However,the large-scale applications of Li_(2)S cathodes are limited by the shuttle effect of soluble intermediate lithium polysulfides(LiPSs)and the sluggish redox kinetics of the interconversion between Li_(2)S and sulfur(S).Herein,we report novel nitrogen-doped carbon nanoflakes in-situ embedded with WN-Ni_(2)P heterostructures(WN-Ni_(2)P@NCN)as a multifunctional host to promote the cycling performance and reaction kinetics of Li_(2)S.After loading Li_(2)S,the WNNi_(2)P@NCN/Li_(2)S exhibits stable reversible capacity of 597mAh g^(-1)at 0.5 A g^(-1)over 150 cycles,and superior cycling stability over 800 cycles.The high reversible capacities,excellent cycling properties and superior reaction kinetics of WN-Ni_(2)P@NCN/Li_(2)S are attributed to the strong LiPSs fixation,remarkable catalytic activation and high electronic/ionic conductivity of the WN-Ni_(2)P@NCN framework,confirmed by the experiment and the density function theory calculation results.This work offers a new strategy for designing heterostructure nanoflakes with metal nitride and metal phosphide to facilitate the applications of advanced lithium-sulfur batteries.
基金financially supported by the Liaoning Revitalization Talents Program(No.XLYC2203133)the Fundamental Research Funds for the Central Universities(No.N2302018)the Ningbo Yuyao City Science and Technology Plan Project(No.2023J03010010).
文摘Nickel-based alloys applied in marine environments often face multiple challenges of stress,corrosion and wear.In this work,heterostructured NiCrTi alloy was prepared by spark plasma sintering coarse Ni20Cr and ultrafine Ti powders.Apart that some are dissolved into the nickel alloy,Ti powders react in situ with Ni20Cr during sintering to form hard intermetallic Ni_(3)Ti.It builds up a typical heterostructure that endows NiCrTi alloy with well-balanced mechanical strength and plasticity,e.g.high yield strength of 1321 MPa,compressive strength of 2470 MPa,and compressive strain of 20%.On tribocorrosion,the hard shell enriched with Ti transforms to connected protrusion and form in situ surface texture.Oxides or wear debris are trapped at the textured surface and compacted to form a stable tribofilm.Thus negative synergy between corrosion and wear is observed for NiCrTi and high tribocorrosion resistance is achieved.At a potential of+0.3 V,the tribocorrosion rate of NiCrTi is reduced by an order of magnitude to 1.87×10^(-5)mm^(3)/(Nm)in comparison to the alloy Ni20Cr.
基金the National Natural Science Foundation of China(Grant no.52475342,51975175 and 52375329).
文摘The heterostructure preparation in Mg-rare earth(RE)alloy has attracted much attention due to the excellent enhancement of strength and ductility.However,the effect of heterostructure composition on mechanical properties in Mg-RE alloy is still not clear.In this work,three types of heterostructures with different composition induced by lamellar 14H long period stacking ordered(LPSO)phase were achieved in the Mg-Gd-Y-Zn-Zr alloys after cyclic extrusion and compression(CEC).The heterostructure was mainly composed of dynamic recrystallization(DRX)grains,deformed coarse grains,multiscale LPSO phase(blocky,granular,lamellar LPSO phase).The strength and ductility of Mg-Gd-Y-Zn-Zr alloy with heterostructure were simultaneously improved.The DRX behavior during CEC process was largely affected by the lamellar LPSO phase.The lamellar LPSO with large spacing(∼92 nm)and low thickness(∼13.46 nm)is easy to occur kinking behavior and the zigzag kinking area can serve as nucleation sites to promote DRX behavior.While the lamellar LPSO phase with high thickness(∼23.41 nm)and similar spacing(∼82 nm)was ruptured into granular LPSO phase and thus increase the volume fraction of granular LPSO phase,which made a great contribution to DRX behavior by particle stimulated nucleation.The main deformation mechanism of solution treatment+furnace cooling(SF)sample during CEC process is dominated by the multiple slips composed of basal slips,prismatic slips and pyramidal slips.For the solution treatment+air cooling(SA)sample and solution treatment+ageing treatment(ST)sample,the activation of basal slips is the critical deformation mechanism.The main contribution to yield strength is from the grain boundary,dislocation and hetero-deformation induced(HDI)strengthening.Moreover,the HDI strengthening in the SF and SA sample after CEC deformation is much larger than that of ST sample due to the distinct heterostructure composition.
基金supported by the National Natural Science Foundation of China(No.22265017)the Open Fund of Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education(No.KF-21-04).
文摘In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported.Selenization temperature plays a significant role in determining the phases,morphology,and lithium-ion storage performance of the composite.Notably,the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g,surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C-or ZnSe@C-based anodes.Furthermore,ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite.
基金financially supported by the National Natural Science Foundation of China(No.52071035)the Doctoral Scientific Research Foundation of Anhui University of Technology(No.RZ2400002557).
文摘Heterostructured materials as a new class can effectively avoid the inverted relationship of the“banana”curve followed by strength-ductility.The difference in grain size is the mainstream idea of the design of heterogeneous zones.However,the synergistic strengthening mechanism and deformation behavior among multi-scale heterostructures are still unclear.In this work,AZ80/AZ31 laminate with a multi-scale heterogeneous distribution of grain size,precipitates,and texture between alternate AZ31 and AZ80 component layers,which was constructed by accumulative extrusion bonding combined with aging treatment.The composite samples after 2-pass extrusion presented an outstanding strength-ductility synergy,which was attributed to the joint action of texture softening and hardening,grain refinement as well as multistage heterogeneous deformation induced(HDI)strengthening and hardening.Multi-types of heterogeneous regions provided more sites for geometrically necessary dislocation accumulation to accommodate multiple strain gradients under the constraint of multi-layer interfaces,enhancing HDI stress.The synergistic effect of great Schmid factor difference and increasing geometric compatibility factor between adjacent grains at the layer interface led to strain transfer behavior,which facilitated strain delocalization.This work expands the design ideas and preparation methods of heterostructured materials and enriches the theory of heterogeneous deformation.
基金supported by the National Natural Science Foundation of China (Nos. 22171287, 51972342, 52303274)Taishan Scholar Project of Shandong Province (tsqn202103046 and ts20190922)+1 种基金Natural Science Foundation of Shandong Province (ZR2024QB076, ZR2022QE175)Fundamental Research Funds for the Central Universities (24CX07007A and 22CX01002A-1)
文摘Creating strongly coupled heterostructures with favorable catalytic activities is crucial for promoting the performance of catalytic reactions,especially those involve multiple intermediates.Herein,we fabricated a strongly coupled platinum/molybdenum nitrides nanocluster heterostructure on nitrogen-doped reduced graphene oxide(Pt/Mo_(2)N-NrGO)for alkaline hydrogen evolution reaction.The well-defined Pt-containing Anderson-type polyoxometalates promote strong interfacial Pt-N-Mo bonding in Pt/Mo_(2)N-NrGO,which exhibits a remarkably low overpotential,high mass activity,and exceptional long-term durability(>500 h at 1500 mA cm^(-2))in an anion-exchange membrane water electrolyzer(AEMWE).Operando Raman spectroscopy and density functional theory reveal that pronounced electronic coupling at the Pt/Mo_(2)N cluster interface facilitates the catalytic decomposition of H_(2)O through synergistic stabilization of intermediates(Pt-H^(*)and Mo-OH^(*)),thereby enhancing the kinetics of the rate-determining Volmer step.Techno-economic analysis indicates a levelized hydrogen production cost of$2.02 kg^(-1),meeting the US DOE targets.Our strategy presents a viable pathway to designing next-generation catalysts for industrial AEMWE for green hydrogen production.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52171206 and52271209)Key Project of Hebei Natural Science Foundation(Nos.F2024201031 and E20202201030)+4 种基金Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project(No.21344301D)the Second Batch of Young Talent of Hebei Province(Nos.70280016160250 and 70280011808)Key Fund in Hebei Province Department of Education China(No.ZD2021014)the Central Government Guide Local Funding Projects for Scientific and Technological Development(Nos.216Z4404G and 206Z4402G)Interdisciplinary Research Program of Natural Science of Hebei University(No.DXK202107)。
文摘The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathode material with a p-n heterostructure of polyaniline(PANI)/ZnS is prepared to trap visible light,utilizing a ZnS quantum dot(ZnS QD)network to form a large number of photogenerated electron–hole pairs,thus promoting the generation and decomposition of Li_(2)O_(2).The prepared PANI/ZnS has an ultra-low overpotential of 0.06 V under illumination.Furthermore,density functional theory theoretical calculation has demonstrated the ability of the heterostructures to adsorb oxygen-containing intermediates,which not only facilitates the growth of Li_(2)O_(2),but also reduces the reaction energy required to decompose Li_(2)O_(2).The present work provides a solution to the problem of insolubility of discharge products in photo-assisted LOB.
基金supported by the Natural Science Foundation of Fujian Province of China(2022J01646)。
文摘The heterostructures incorporated with two or more distinctive two-dimensional(2D)materials have attracted great attention be-cause they could give rise to enhanced prop-erty in comparison with their individual counterparts.Here,a water-assisted two-step rapid physical vapor deposition(rPVD)method was explored and used to synthesize Bi_(2)Te_(3)-Sb_(2)Te_(3)lateral het-erostructures(LHS)successfully.The Bi_(2)Te_(3)-Sb_(2)Te_(3)LHS is in nearly uniform size,and grows along three particular orientations with the intersection angles of 120°.Inter-estingly,we found that the water molecules play a significant role in determining the growth orientation,namely whether it will grow along the vertical or lateral direction in 2D structure.Hence,a growth mechanism of LHS based on the water-assisted two-step rPVD was present,which can be used as a general strategy and extended to the growth of other 2D heterostruc-tures or homostructures,such as SnS-SnSe LHS and SnS-SnS lateral homostructures.Fur-thermore,the second-harmonic generation intensity of the Bi_(2)Te_(3)-Sb_(2)Te_(3)LHS is much stronger than that of the Bi_(2)Te_(3)/Sb_(2)Te_(3)vertical heterostructures(VHS).This work opens a new approach for the synthesis of water-assisted lateral 2D heterostructures or homostruc-tures and offers a new method to enhance the second-harmonic generation properties of topo-logical insulating materials.
