Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems cons...Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.展开更多
Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupli...Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupling,and 1T-VTe_(2)monolayer theoretically predicted to host an intrinsic magnetism as experimentally suggested.In this work,we successfully constructed a vertical heterostructure composed of the two-dimensional Bi(110)monolayer and 1T-VTe_(2)monolayer by using molecular beam epitaxy(MBE).Scanning tunneling microscopy(STM)measurements revealed that the growth of Bi preferably occurs along the step edges of the VTe_(2)monolayer,forming a Bi(110)monolayer on top of the VTe_(2)monolayer next to a peripheral Bi bilayer.The Bi(100)/VTe_(2)heterostructure exhibits a specific lattice registry with a well-defined moiréperiodicity.Scanning tunneling spectroscopy(STS)measurements further unveiled an universal suppression in the local density-of-states at the boundary of the Bi(110)/VTe_(2)bilayer.By examining the atomic structures of Bi(110)boundaries,we found this effect does not originate from the previously proposed atomic reconstruction at the step edge of Bi(110),but is likely related to the magnetic properties of the VTe_(2)monolayer.展开更多
We report on the growth of CoFe_(2)O_(4)/Pt heterostructure and their magnetotransport properties.The magnetoresistance under high magnetic fields exhibits a sign change when the temperature increases from 5 K to 10 K...We report on the growth of CoFe_(2)O_(4)/Pt heterostructure and their magnetotransport properties.The magnetoresistance under high magnetic fields exhibits a sign change when the temperature increases from 5 K to 10 K.The anomalous Hall resistance decreases as the temperature increases.Furthermore,angle-dependent magnetoresistance indicates that the observed magnetotransport behaviors originate from the competition between the spin Hall magnetoresistance and magnetic proximity effect.展开更多
The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising c...The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising candidates due to their built-in electric fields,ultrafast photocarrier separation,and tunable bandgaps,defect states limit their performance.Therefore,the modulation of the optoelectronic properties in such heterostructures is imperative.Surface charge transfer doping(SCTD)has emerged as a promising strategy for non-destructive modulation of electronic and optoelectronic characteristics in two-dimensional materials.In this work,we demonstrate the construction of high-performance p-i-n vertical heterojunction photodetectors through SCTD of MoTe_(2)/ReS_(2)heterostructure using p-type F_(4)-TCNQ.Systematic characterization reveals that the interfacial doping process effectively amplifies the built-in electric field,enhancing photogenerated carrier separation efficiency.Compared to the pristine heterojunction device,the doped photodetector exhibits remarkable visible to nearinfrared(635-1064 nm)performance.Particularly under 1064 nm illumination at zero bias,the device achieves a responsivity of 2.86 A/W and specific detectivity of 1.41×10^(12)Jones.Notably,the external quantum efficiency reaches an exceptional value of 334%compared to the initial 11.5%,while maintaining ultrafast response characteristics with rise/fall times of 11.6/15.6μs.This work provides new insights into interface engineering through molecular doping for developing high-performance vd W optoelectronic devices.展开更多
As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM c...As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM cells based on conventional silicon-based devices suffer from structural complexity and large footprintlimitations. Here, we demonstrate an ultrafast nonvolatile TCAM cell based on the MoTe2/hBN/multilayergraphene (MLG) van der Waals heterostructure using a top-gated partial floating-gate field-effect transistor(PFGFET) architecture. Based on its ambipolar transport properties, the carrier type in the source/drain andcentral channel regions of the MoTe2 channel can be efficiently tuned by the control gate and top gate, respectively,enabling the reconfigurable operation of the device in either memory or FET mode. When working inthe memory mode, it achieves an ultrafast 60 ns programming/erase speed with a current on-off ratio of ∼105,excellent retention capability, and robust endurance. When serving as a reconfigurable transistor, unipolar p-typeand n-type FETs are obtained by adopting ultrafast 60 ns control-gate voltage pulses with different polarities.The monolithic integration of memory and logic within a single device enables the content-addressable memory(CAM) functionality. Finally, by integrating two PFGFETs in parallel, a TCAM cell with a high current ratioof ∼10^(5) between the match and mismatch states is achieved without requiring additional peripheral circuitry.These results provide a promising route for the design of high-performance TCAM devices for future in-memorycomputing applications.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
In this work,silicon-carbon hybrid materials were adopted as an example to illustrate the novel strategy to in situ construct heterostructure with adjustable microstructure.Based on the temperature-dependent thermodyn...In this work,silicon-carbon hybrid materials were adopted as an example to illustrate the novel strategy to in situ construct heterostructure with adjustable microstructure.Based on the temperature-dependent thermodynamics and kinetics of reaction between Si and C,the processes for Si nanocrystals growth and C decoration were coupled at different zones of plasma flame according to its temperature and velocity fields by theoretical modeling,aiming to intentionally suppress the formation of undesirable carbide,and enable adjusting the microstructure of each counterpart separately in transient process.As a result,well-controlled Si/C nanocomposites,including nanospheres and nanowires with core-shell structures,were achieved,and this continuous and in-flight route is also potential for large-scale production.Further investigation on the electrochemical properties highlights the advantage of as proposed strategy to efficiently construct heterostructures with superior performance for various applications.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
The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a su...The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a sustainable society,which is independent of fossil fuels.In this regard,electrochemical water splitting based on the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is an attractive technique for producing carbon-free hydrogen fuels.Additionally,rechargeable metal–air batteries(MABs)are another intriguing way for renewable energy storage through reversible oxygen reactions(OER and the oxygen reduction reaction,ORR).Herein,we comprehensively review bifunctional electrocatalysts for water splitting(HER and OER)and MABs(OER and ORR),particularly 2D carbon material-derived heterostructures.The synthesis and properties of 2D carbon materials and their energy conversion and storage mechanisms are discussed to highlight the bifunc-tionality of the heterostructures.Recent studies on bifunctional electrocatalysts based on 2D carbon-derived heterostructures are also reviewed.Finally,perspectives for future studies and multifunctional catalysts are presented.展开更多
Traditional metals often exhibit a trade-offbetween strength and plasticity,limiting their wide application of metals in aerospace,transportation,energy industry and other fields[1-3].In order to overcome this dilemma...Traditional metals often exhibit a trade-offbetween strength and plasticity,limiting their wide application of metals in aerospace,transportation,energy industry and other fields[1-3].In order to overcome this dilemma,high-entropy alloys(HEAs),proposed by Yeh et al.and Cantor et al.,are currently of great interest in the materials community due to their excellent mechanical properties[4-7].To further promote the wide application of HEAs in industrial production,Lu et al.developed a new eutectic high-entropy alloy(EHEAs)by combining the potential advantages of traditional eutectic alloys and HEAs[8-11].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
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
Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride he...Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures(denoted PtPdAu/BiTe)were synthesized using a visible-light-assisted strategy.The coupling alloy and interfacial effects of PtPdAu/BiTe significantly improved the performance and stability of both the ethanol oxidation reaction(EOR)and methanol oxidation reaction(MOR).Introducing a small amount of Au effectively enhanced the CO tolerance of PtPdAu/BiTe compared to dendritic platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures.PtPdAu/BiTe exhibited mass activities of 31.5 and 13.3 A·mg_(Pt)^(-1)in EOR and MOR,respectively,which were 34.4 and 13.2 times higher than those of commercial Pt black,revealing efficient Pt atom utilization.In-situ Fourier transform infrared spectroscopy demonstrated complete 12e^(-)and 6e^(-)oxidation of ethanol and methanol on PtPdAu/BiTe.The PtPdAu/BiTe/C achieved mass peak power densities of 131 and 156 mW·mg_(Pt)^(-1),which were 2.4 and 2.2 times higher than those of Pt/C in practical direct ethanol fuel cell(DEFC)and direct methanol fuel cell(DMFC),respectively,highlighting their potential application in DEFC and DMFC.This study introduces an effective strategy for designing efficient and highly CO tolerant anodic electrocatalysts for practical DEFC and DMFC applications.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
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
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
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
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
Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial...Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial-level current density due to high concentration of salts and compete reaction of chlorine evolution.Herein,a 1D NiFe_(2)O_(4)/NiMoO_(4) heterostructure as a bifunctional electrocatalyst for overall seawater splitting is constructed by combining NiMoO_(4) nanowires with NiFe_(2)O_(4)nanoparticles on carbon felt(CF)by a simple hydrothermal,impregnation and calcination method.The electrocatalyst exhibits low overpotential of 237 and 292 mV for oxygen evolution reaction and hydrogen evolution reaction at 400 m A/cm^(2)in the alkaline seawater(1 mol/L KOH+0.5 mol/L NaCl)due to the plentiful interfaces of NiFe_(2)O_(4)/NiMoO_4 which exposes more active sites and expands the active surface area,thereby enhancing its intrinsic activity and promoting the reaction kinetics.Notably,it displays low voltages of 1.95 V to drive current density of 400 m A/cm^(2)in alkaline seawater with its excellent stability of 200 h at above 100 m A/cm^(2),exhibiting outstanding performance and good corrosion resistance.This work provides an effective strategy for constructing efficient and cost-effective electrocatalysts for industrial seawater electrolysis,underscoring its potential for sustainable energy applications.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
基金supported by the National Key R&D Program of China (Grant Nos.2022YFA1403103 and 2019YFA0308603)the National Natural Science Foundation of China (Grant No.12304167)the Shandong Provincial Natural Science Foundation of China (Grant No.ZR2023QA020)。
文摘Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.
基金financially supported by the National Key Research and Development Program of China(Grant No.2021YFA1400403)the National Natural Science Foundation of China(Grant Nos.12374183,92165205)+2 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the Fundamental Research Funds for the Central Universities(Grant No.020414380207).
文摘Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupling,and 1T-VTe_(2)monolayer theoretically predicted to host an intrinsic magnetism as experimentally suggested.In this work,we successfully constructed a vertical heterostructure composed of the two-dimensional Bi(110)monolayer and 1T-VTe_(2)monolayer by using molecular beam epitaxy(MBE).Scanning tunneling microscopy(STM)measurements revealed that the growth of Bi preferably occurs along the step edges of the VTe_(2)monolayer,forming a Bi(110)monolayer on top of the VTe_(2)monolayer next to a peripheral Bi bilayer.The Bi(100)/VTe_(2)heterostructure exhibits a specific lattice registry with a well-defined moiréperiodicity.Scanning tunneling spectroscopy(STS)measurements further unveiled an universal suppression in the local density-of-states at the boundary of the Bi(110)/VTe_(2)bilayer.By examining the atomic structures of Bi(110)boundaries,we found this effect does not originate from the previously proposed atomic reconstruction at the step edge of Bi(110),but is likely related to the magnetic properties of the VTe_(2)monolayer.
基金supported by the National Natural Science Foundation of China(Grant Nos.62525406,T2394473,624B2070,and 62274085)the National Key Research and Development Program of China(Grant No.2022YFA1402404)the Innovation Program for Quantum Science and Technology of China(Grant No.2024ZD0301300)。
文摘We report on the growth of CoFe_(2)O_(4)/Pt heterostructure and their magnetotransport properties.The magnetoresistance under high magnetic fields exhibits a sign change when the temperature increases from 5 K to 10 K.The anomalous Hall resistance decreases as the temperature increases.Furthermore,angle-dependent magnetoresistance indicates that the observed magnetotransport behaviors originate from the competition between the spin Hall magnetoresistance and magnetic proximity effect.
基金financial support from 2024 Domestic Visiting Scholar Program for Teachers'Professional Development in Universities(Grant No.FX2024022)National Natural Science Foundation of China(Grant No.61904043)。
文摘The development of optoelectronic technologies demands photodetectors with miniaturization,broadband operation,high sensitivity,and low power consumption.Although 2D van der Waals(vd W)heterostructures are promising candidates due to their built-in electric fields,ultrafast photocarrier separation,and tunable bandgaps,defect states limit their performance.Therefore,the modulation of the optoelectronic properties in such heterostructures is imperative.Surface charge transfer doping(SCTD)has emerged as a promising strategy for non-destructive modulation of electronic and optoelectronic characteristics in two-dimensional materials.In this work,we demonstrate the construction of high-performance p-i-n vertical heterojunction photodetectors through SCTD of MoTe_(2)/ReS_(2)heterostructure using p-type F_(4)-TCNQ.Systematic characterization reveals that the interfacial doping process effectively amplifies the built-in electric field,enhancing photogenerated carrier separation efficiency.Compared to the pristine heterojunction device,the doped photodetector exhibits remarkable visible to nearinfrared(635-1064 nm)performance.Particularly under 1064 nm illumination at zero bias,the device achieves a responsivity of 2.86 A/W and specific detectivity of 1.41×10^(12)Jones.Notably,the external quantum efficiency reaches an exceptional value of 334%compared to the initial 11.5%,while maintaining ultrafast response characteristics with rise/fall times of 11.6/15.6μs.This work provides new insights into interface engineering through molecular doping for developing high-performance vd W optoelectronic devices.
基金supported by the National Key Research&Development Projects of China(Grant No.2022YFA1204100)National Natural Science Foundation of China(Grant No.62488201)+1 种基金CAS Project for Young Scientists in Basic Research(YSBR-003)the Innovation Program of Quantum Science and Technology(2021ZD0302700)。
文摘As a typical in-memory computing hardware design, nonvolatile ternary content-addressable memories(TCAMs) enable the logic operation and data storage for high throughout in parallel big data processing. However,TCAM cells based on conventional silicon-based devices suffer from structural complexity and large footprintlimitations. Here, we demonstrate an ultrafast nonvolatile TCAM cell based on the MoTe2/hBN/multilayergraphene (MLG) van der Waals heterostructure using a top-gated partial floating-gate field-effect transistor(PFGFET) architecture. Based on its ambipolar transport properties, the carrier type in the source/drain andcentral channel regions of the MoTe2 channel can be efficiently tuned by the control gate and top gate, respectively,enabling the reconfigurable operation of the device in either memory or FET mode. When working inthe memory mode, it achieves an ultrafast 60 ns programming/erase speed with a current on-off ratio of ∼105,excellent retention capability, and robust endurance. When serving as a reconfigurable transistor, unipolar p-typeand n-type FETs are obtained by adopting ultrafast 60 ns control-gate voltage pulses with different polarities.The monolithic integration of memory and logic within a single device enables the content-addressable memory(CAM) functionality. Finally, by integrating two PFGFETs in parallel, a TCAM cell with a high current ratioof ∼10^(5) between the match and mismatch states is achieved without requiring additional peripheral circuitry.These results provide a promising route for the design of high-performance TCAM devices for future in-memorycomputing applications.
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financially supported by the National Natural Science Foundation of China(No.52174342)Beijing Natural Sci-ence Foundation(No.2232044)Beijing Municipal Education Commission Research Plan General Project(No.KM202410005009).
文摘In this work,silicon-carbon hybrid materials were adopted as an example to illustrate the novel strategy to in situ construct heterostructure with adjustable microstructure.Based on the temperature-dependent thermodynamics and kinetics of reaction between Si and C,the processes for Si nanocrystals growth and C decoration were coupled at different zones of plasma flame according to its temperature and velocity fields by theoretical modeling,aiming to intentionally suppress the formation of undesirable carbide,and enable adjusting the microstructure of each counterpart separately in transient process.As a result,well-controlled Si/C nanocomposites,including nanospheres and nanowires with core-shell structures,were achieved,and this continuous and in-flight route is also potential for large-scale production.Further investigation on the electrochemical properties highlights the advantage of as proposed strategy to efficiently construct heterostructures with superior performance for various applications.
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supported by National R&D Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(Nos.2022R1F1A1072420 and NRF-2020R1A3B2079803).
文摘The continuous depletion of fossil fuels and the effects of climate change have encouraged prompt action to attain carbon neutrality.Technologies that transform and store renewable energy are crucial for creating a sustainable society,which is independent of fossil fuels.In this regard,electrochemical water splitting based on the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is an attractive technique for producing carbon-free hydrogen fuels.Additionally,rechargeable metal–air batteries(MABs)are another intriguing way for renewable energy storage through reversible oxygen reactions(OER and the oxygen reduction reaction,ORR).Herein,we comprehensively review bifunctional electrocatalysts for water splitting(HER and OER)and MABs(OER and ORR),particularly 2D carbon material-derived heterostructures.The synthesis and properties of 2D carbon materials and their energy conversion and storage mechanisms are discussed to highlight the bifunc-tionality of the heterostructures.Recent studies on bifunctional electrocatalysts based on 2D carbon-derived heterostructures are also reviewed.Finally,perspectives for future studies and multifunctional catalysts are presented.
基金financial supported by the Natural Science Foundation of Jiangsu Provincial Education Department(No.24KJB430003)the Natural Science Foundation for Young Scholars of Jiangsu Province(No.BK20240979)+3 种基金support of Natural Science Foundation for Young Scholars of Jiangsu Province(No.BK20220628)the National Natural Science Foundation for Young Scholars of China(52301130)the Changzhou Sci&Tech program(No.GJ20220153)support of the Natural Science Foundation of Jiangsu Provincial Education Department(No.21KJB430001).
文摘Traditional metals often exhibit a trade-offbetween strength and plasticity,limiting their wide application of metals in aerospace,transportation,energy industry and other fields[1-3].In order to overcome this dilemma,high-entropy alloys(HEAs),proposed by Yeh et al.and Cantor et al.,are currently of great interest in the materials community due to their excellent mechanical properties[4-7].To further promote the wide application of HEAs in industrial production,Lu et al.developed a new eutectic high-entropy alloy(EHEAs)by combining the potential advantages of traditional eutectic alloys and HEAs[8-11].
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supported by the National Natural Science Foundation of China(No.22465009)the Education Department of Guizhou Province(No.2021312)the Foundation of Guizhou Province(No.2019-5666).
文摘Alloying and interface effects are effective strategies for enhancing the performance of electrocatalysts in energy-related devices.Herein,dendritic Au-doped platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures(denoted PtPdAu/BiTe)were synthesized using a visible-light-assisted strategy.The coupling alloy and interfacial effects of PtPdAu/BiTe significantly improved the performance and stability of both the ethanol oxidation reaction(EOR)and methanol oxidation reaction(MOR).Introducing a small amount of Au effectively enhanced the CO tolerance of PtPdAu/BiTe compared to dendritic platinum-palladium alloy/dumbbell-like bismuth telluride heterostructures.PtPdAu/BiTe exhibited mass activities of 31.5 and 13.3 A·mg_(Pt)^(-1)in EOR and MOR,respectively,which were 34.4 and 13.2 times higher than those of commercial Pt black,revealing efficient Pt atom utilization.In-situ Fourier transform infrared spectroscopy demonstrated complete 12e^(-)and 6e^(-)oxidation of ethanol and methanol on PtPdAu/BiTe.The PtPdAu/BiTe/C achieved mass peak power densities of 131 and 156 mW·mg_(Pt)^(-1),which were 2.4 and 2.2 times higher than those of Pt/C in practical direct ethanol fuel cell(DEFC)and direct methanol fuel cell(DMFC),respectively,highlighting their potential application in DEFC and DMFC.This study introduces an effective strategy for designing efficient and highly CO tolerant anodic electrocatalysts for practical DEFC and DMFC applications.
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 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supported by the National Natural Science Foundation of China(No.51908408)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2019KJ008)Basic Research Program of Jiangsu Province(No.BK20241845)。
文摘Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial-level current density due to high concentration of salts and compete reaction of chlorine evolution.Herein,a 1D NiFe_(2)O_(4)/NiMoO_(4) heterostructure as a bifunctional electrocatalyst for overall seawater splitting is constructed by combining NiMoO_(4) nanowires with NiFe_(2)O_(4)nanoparticles on carbon felt(CF)by a simple hydrothermal,impregnation and calcination method.The electrocatalyst exhibits low overpotential of 237 and 292 mV for oxygen evolution reaction and hydrogen evolution reaction at 400 m A/cm^(2)in the alkaline seawater(1 mol/L KOH+0.5 mol/L NaCl)due to the plentiful interfaces of NiFe_(2)O_(4)/NiMoO_4 which exposes more active sites and expands the active surface area,thereby enhancing its intrinsic activity and promoting the reaction kinetics.Notably,it displays low voltages of 1.95 V to drive current density of 400 m A/cm^(2)in alkaline seawater with its excellent stability of 200 h at above 100 m A/cm^(2),exhibiting outstanding performance and good corrosion resistance.This work provides an effective strategy for constructing efficient and cost-effective electrocatalysts for industrial seawater electrolysis,underscoring its potential for sustainable energy applications.
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.
