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
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
The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage te...The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage technologies,asymmetric supercapacitor(ASC)has garnered significant attention owing to its high energy density and power density.In the quest for advanced electrode materials for ASC,the integration of 2D layered heterostructures on hierarchical porous carbon(HPC)substrates has emerged as a promising approach to enhance the electrochemical performance.Herein,a highly innovative hierarchical NiCo LDH/MoS_(2)/HPC heterostructure was successfully synthesized using a simple two-step hydrothermal method for the electrode materials of ASC.Benefiting from the unique hierarchical heterostructure of NiCo LDH/MoS_(2)/HPC composite and the synergistic effect between the components,it reveals an exceptional specific capacitance of 2368 F/g at 0.5 A/g in a three-electrode system,which significantly exceeds that of conventional supercapacitor electrodes.Additionally,the ASC device of NiCo LDH/MoS_(2)/HPC//HPC achieves remarkable specific capacitance of 236 F/g at 0.5 A/g and an impressive energy density of 84Wh/kg at a power density of 400 W/kg,as well as superior cyclic stability.This study not only demonstrates the effectiveness of incorporating MoS_(2) and NiCo LDH into a carbon-based framework for supercapacitor applications but also opens avenues for designing more efficient energy storage devices.展开更多
Accurate quantification of the spin–orbit torques(SOTs) is critical for the identification and applications of new spin-orbitronic effects. One of the most popular techniques to quantify the SOTs is the “switching a...Accurate quantification of the spin–orbit torques(SOTs) is critical for the identification and applications of new spin-orbitronic effects. One of the most popular techniques to quantify the SOTs is the “switching angle shift”, where the applied direct current is assumed to shift, via domain wall depinning during anti-domain expansion, the switching angle of a perpendicular magnetization in a linear proportional manner under a large rotating magnetic field. Here, we report that, for the most commonly employed perpendicular magnetization heterostructures in spintronics(e.g., those based on FeCoB, Co, and Co/Ni multilayers), the switching angle shift considerably misestimates the SOT within the domain wall depinning analysis of the slope of linear-in-current scaling and may also have a non-zero residual value at zero direct current. Our experiments and simulations unveil that the switching angle shift is most likely dominated by chiral asymmetric nucleation rather than expansion of anti-domains. The in-plane field from external magnets and current-induced SOTs lowers the perpendicular nucleation field and thus reduces the required switching angle, ultimately leading to an underestimation of SOTs by domain wall depinning analysis. These results have advanced our understanding of magnetization switching in spintronic devices.展开更多
Research on p-channel field-effect transistors(p-FETs)remains limited,primarily due to the significantly lower conductivity of the two-dimensional hole gas(2DHG)compared to the two-dimensional electron gas(2DEG)in n-c...Research on p-channel field-effect transistors(p-FETs)remains limited,primarily due to the significantly lower conductivity of the two-dimensional hole gas(2DHG)compared to the two-dimensional electron gas(2DEG)in n-channel field-effect transistors(n-FETs),which poses a significant challenge for monolithic integration.In this study,we investigate the impact of epitaxial structure parameters on 2DHG properties in p-Ga N/Al Ga N/Ga N heterostructures through semiconductor technology computer-aided design(TCAD)simulations and theoretical calculations,identifying the conditions necessary to achieve high-density 2DHG.Our simulations demonstrate that increasing the p-Ga N thickness leads to two critical thicknesses determined by surface states and acceptor ionization concentration:one corresponds to the onset of 2DHG formation,and the other to its saturation.Lowering the donor surface state energy level and increasing the acceptor ionization concentration promote 2DHG formation and saturation,although the saturated density remains independent of surface states.Additionally,a higher Al composition enhances intrinsic ionization due to stronger polarization effects,thereby increasing the 2DHG sheet density.Consequently,to achieve high-density 2DHG in p-Ga N/Al Ga N/Ga N heterostructures,it is essential to increase the Al composition,ensure that the p-Ga N thickness exceeds the critical thickness for 2DHG saturation,and maximize the acceptor ionization concentration.This study elucidates the impact of epitaxial structure parameters on 2DHG properties in p-Ga N/Al Ga N/Ga N heterostructures and provides valuable guidance for the optimization of p-FET designs.展开更多
The rational design of composition and microstructure is a proven strategy for developing multifunctional high-performance electromagnetic wave(EMW)absorbers.In this study,a sandwich-structured multilayer nanoplate-li...The rational design of composition and microstructure is a proven strategy for developing multifunctional high-performance electromagnetic wave(EMW)absorbers.In this study,a sandwich-structured multilayer nanoplate-like Bi_(2)Fe_(4)O_(9)@Polypyrrole(BFO@PPy)heterostructure was successfully designed and fabricated using an efficient microwave hydrothermal method and an in situ polymerization process.Specifically,Bi_(2)Fe_(4)O_(9)enhances the chemical activity of ammonium persulfate,which in turn initiates the polymerization of pyrrole monomers,resulting in the formation of BFO@PPy heterostructures.The thickness of the PPy coating layer in the BFO@PPy composite can be precisely controlled at the nanoscale,optimizing electromagnetic parameters,conduction losses and interface polarization loss.The fabricated BFO@PPy composite achieves a minimum reflection loss(RL_(min))of-57.8 dB at a thickness of 2.5 mm and an effective absorption bandwidth(EAB)of 6.96 GHz.Furthermore,the EMW absorption performance and mechanism were systematically validated through theoretical calculations,radar cross-sectional simulations(RCS),and first-principles analysis.Notably,the RCS simulation of a 1:1 scale F-22 Raptor fighter model provides a realistic evaluation of the composite's EMW absorption potential in military applications.The efficient fabrication method and superior electromagnetic absorption performance make BFO@PPy a promising candidate for use in complex electromagnetic environments and military domains.Additionally,the BFO@PPy composite exhibits rapid electrothermal conversion at a low voltage(3V),achieving active infrared camouflage within a controllable temperature range,further highlighting its multifunctional properties.展开更多
Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell...Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell heterostructure were successfully prepared through simple template and solvothermal methods.Thanks to the hollow structure,cross-linked nanowire arrays,and in-situ coating of zeolite imidazole framework(ZIF),Co_(3)S_(4)@NiCo_(2)S_(4) demonstrated excellent electrochemical performance with a specific ca-pacitance of up to 2697.7 F g^(-1)at 1 A g^(-1) and cycling stability of 80.5% after 5000 cycles.The covalent organic framework(COF)derived nano carbon,which had undergone secondary calcination and ZnCl_(2) activation,also exhibited excellent double-layer energy storage performance.Compared to a single calci-nation,the incredible increase in capacitance was up to 208.5 times greater,reaching 291.9 F g^(-1)at 1 A g^(-1)while maintaining ultra-high rate performance(81.0%at 20 A g^(-1)).The hybrid supercapacitor,assem-bled with Co_(3)S_(4)@NiCo_(2)S_(4)as the cathode and COF-derived carbon as the anode,exhibited an extremely high energy density(79.7 Wh kg^(-1)at 693.5 W kg^(-1))and excellent cyclic stability(maintained 79.3%after 10,000 cycles of 20 A g^(-1)),further explaining the reliable and practical characteristics.This work provided reference for the structural optimization of transition metal sulfides and the high-temperature activation of COF-derived carbon.展开更多
The reduction of global carbon emissions and the achievement of carbon neutrality have become the focus of addressing climate change and global warming.Electrochemical CO_(2) reduction(CO_(2)RR),as a technology that c...The reduction of global carbon emissions and the achievement of carbon neutrality have become the focus of addressing climate change and global warming.Electrochemical CO_(2) reduction(CO_(2)RR),as a technology that can efficiently convert CO_(2) into value-added products,is receiving widespread attention.This article reviews the current research status of Cu/metal oxide heterostructures in the field of electrochemical reduction of CO_(2).The review first introduces the importance of electrochemical reduction of CO_(2) and the application potential of Cu/metal oxide heterostructures in this field.Subsequently,a comprehensive discussion is presented on the exploration of various Cu/metal oxide heterostructures and their corresponding structure-performance relationship,with particular emphasis on the catalysts'activity,selectivity,stability and the nature of active sites.Lastly,the review provides an overview of the current research challenges and future development trends in this field.展开更多
Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capp...Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.展开更多
Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is...Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is explored by filling CNTs with one-dimensional(1D)-TM_(6)Te_(6) nanowires to form TM_(6)Te_(6)@CNT-(16,0) 1D van der Waals heterostructures(1D-vd WHs). The systematic first-principles studies on the electronic properties of 1D-vd WHs show that N-type doping CNTs can be formed by charge transfer from TM_(6)Te_(6) nanowires to CNTs, without introducing additional carrier scattering.Particularly, contribution from both T M(e.g., Sc and Y) and Te atoms strengthens the charge transfer. The outside CNTs further confine the dispersion of Te-p orbitals in nanowires that deforms the C-π states at the bottom of the conduction band to quasi sp^(3) hybridization. Our study provides an inner doping strategy that can effectively confine the charge polarity of CNTs and further broaden its applications in some novel nano-devices.展开更多
The research on two-dimensional(2D)magnetic materials and their heterostructures is crucial in fields like spintronics,materials science,and condensed matter physics.This study uses terahertz(THz)time-domain spectrosc...The research on two-dimensional(2D)magnetic materials and their heterostructures is crucial in fields like spintronics,materials science,and condensed matter physics.This study uses terahertz(THz)time-domain spectroscopy to investigate ultrafast electron transport properties in both van der Waals Fe_(4)GeTe_(2)films and Bi_(2)Te_(3)/Fe_(4)GeTe_(2)ferromagnetic/topological heterostructures.Our results show that these heterostructures exhibit effective THz electromagnetic shielding.The complex conductivity spectra of Fe_(4)GeTe_(2)films and Bi_(2)Te_(3)/Fe_(4)GeTe_(2)heterostructures with varying Fe_(4)GeTe_(2)thicknesses are analyzed using the Drude-Smith model.We quantitatively examine how Fe_(4)GeTe_(2)layer thickness affects the direct current conductivity,plasma frequency,carrier momentum scattering time,and back-scattering coefficient.As the number of Fe_(4)GeTe_(2)layers increases,intra-layer back-scattering events for charge carriers become more frequent.This work provides THz frequency spectra for both Fe_(4)GeTe_(2)and Bi_(2)Te_(3)/Fe_(4)GeTe_(2),aiding in the design and optimization of THz modulators and detectors.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
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
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
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
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
Constructing a nanostructure that combines abundant active edge sites with a well-designed heterostructure is an effective strategy for enhancing photocatalytic hydrogen generation.However,controllable approaches for ...Constructing a nanostructure that combines abundant active edge sites with a well-designed heterostructure is an effective strategy for enhancing photocatalytic hydrogen generation.However,controllable approaches for creating heterostructures based on vertically standing transition metal dichalcogenide(TMD)nanosheets remain insufficient despite their potential for efficient hydrogen production.In this paper,we present efficient photocatalysts featuring heterojunctions composed of vertically grown TMD(MoS_(2)and WS_(2))nanosheets.These structures(WS_(2),MoS_(2),and MoS_(2)/WS_(2)heterostructure)were fabricated using a controllable metal–organic chemical vapor deposition method,which expanded the surface area and facilitated effective photocatalytic hydrogen evolution.The vertical MoS_(2)/WS_(2)heterostructures demonstrated significantly enhanced hydrogen generation,driven by the synergistic effects of improved light absorption,a large specific surface area,and appropriately arranged staggered heterojunctions.Furthermore,the photocatalytic activity was considerably influenced by the size and density of the vertical nanosheets.Consequently,the nanosheet size-tailored MoS_(2)/WS_(2)heterostructure achieved a photocatalytic hydrogen generation rate(454.2μmol h^(–1) cm^(–2)),which is 2.02 times and 2.19 times higher than that of WS_(2)(225.6μmol h^(-1) cm^(-2))and MoS_(2)(207.2μmol h^(–1) cm^(–2)).Hence,the proposed strategy can be used to design staggered heterojunctions with edge-rich nanosheets for photocatalytic applications.展开更多
Surface adsorption plays a crucial role in various natural and industrial processes,particularly in the field of energy storage.The adsorption of sodium atoms on 2D layered materials can significantly impact their per...Surface adsorption plays a crucial role in various natural and industrial processes,particularly in the field of energy storage.The adsorption of sodium atoms on 2D layered materials can significantly impact their performance as carriers and electrodes in ion batteries.While it is commonly acknowledged that pristine graphene is not favorable for sodium ion adsorption,the suitability of other 2D materials with similar honeycomb symmetry remains unclear.In this study,we employ systematic first-principles calculations to explore interlayer interactions and electron transfer effects on sodium adsorption on 2D van der Waals(vdW)heterostructures(HTSs)surfaces.Our results demonstrate that sodium adsorption is energetically favorable on these substrates.Moreover,we find that the adsorption strength can be effectively tuned by manipulation of the electron accumulation or depletion of the layer directly interacting with the sodium atom.By stacking these layered materials with different electron abundancy to form vd W HTSs,the charge density of the substrate becomes tunable through interlayer charge transfer.In these vdW HTSs,the adsorption behavior of sodium is primarily controlled by the absorption layer and exhibits a linear correlation with its pz-band center.Additionally,we identify linear correlations between the sodium adsorption energies,the electron loss of the sodium atom,the interlayer charge transfer,and the heights of the adsorbed sodium atom.These discoveries underscore the impact of interlayer electron transfer and interactions on sodium ion adsorption on 2D vd W HTSs and providing new insights into material design for alkali atom adsorption.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
Photocatalytic conversion of chemical fuels has emerged as a most challenging subject in photocatalysis which is considered as one of the sustainable solutions for environmental issues related to the energy shortage a...Photocatalytic conversion of chemical fuels has emerged as a most challenging subject in photocatalysis which is considered as one of the sustainable solutions for environmental issues related to the energy shortage and anthropogenic carbon emissions.Herein,unique heterostructures of ZnCdS nanoplates with Bi_(2)S_(3)-terminated edges were prepared through a facile cation exchange pathway,by which the controlled photocatalytic CO_(2)conversion was achieved.The optimized BZCS–NS-5 photocatalyst exhibited an excellent capacity of CO_(2)photoreduction with a CO production rate of ca.513.2-5.1μmol g^(-1)h^(-1)and a selectivity of ca.91.0%,which were among the highest activities for sulfide photocatalysts documented in the literature.The outstanding photocatalytic performance was attributable to the formation of Z-scheme heterostrucutres between Bi_(2)S_(3)and ZnCdS,in a way the separation and migration of photocarriers were accelerated.This work thus provides a feasible strategy for the construction of heterostructures to enhance the activity and selectivity of CO_(2)-to-CO conversion via delicate design and controlled synthesis of photocatalysts.展开更多
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 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 Research and Development Program of China(No.2021YFB3801200)the National Natural Science Foundation of China(Nos.22278051,22178044,and 22308043)the Science and Technology Innovation foundation of CNPC(No.2022DQ02–0608).
文摘The imperative quest for renewable energy sources and advanced energy storage technologies has arisen amidst the escalating perils of climate change and dwindling fossil fuel reserves.In the realm of energy storage technologies,asymmetric supercapacitor(ASC)has garnered significant attention owing to its high energy density and power density.In the quest for advanced electrode materials for ASC,the integration of 2D layered heterostructures on hierarchical porous carbon(HPC)substrates has emerged as a promising approach to enhance the electrochemical performance.Herein,a highly innovative hierarchical NiCo LDH/MoS_(2)/HPC heterostructure was successfully synthesized using a simple two-step hydrothermal method for the electrode materials of ASC.Benefiting from the unique hierarchical heterostructure of NiCo LDH/MoS_(2)/HPC composite and the synergistic effect between the components,it reveals an exceptional specific capacitance of 2368 F/g at 0.5 A/g in a three-electrode system,which significantly exceeds that of conventional supercapacitor electrodes.Additionally,the ASC device of NiCo LDH/MoS_(2)/HPC//HPC achieves remarkable specific capacitance of 236 F/g at 0.5 A/g and an impressive energy density of 84Wh/kg at a power density of 400 W/kg,as well as superior cyclic stability.This study not only demonstrates the effectiveness of incorporating MoS_(2) and NiCo LDH into a carbon-based framework for supercapacitor applications but also opens avenues for designing more efficient energy storage devices.
基金supported by the National Key Research and Development Program of China (Grant No.2022YFA1204000)partly by the National Natural Science Foundation of China (Grant Nos.12274405,12304155,and 12393831)the Beijing Natural Science Foundation (Grant No.Z230006)。
文摘Accurate quantification of the spin–orbit torques(SOTs) is critical for the identification and applications of new spin-orbitronic effects. One of the most popular techniques to quantify the SOTs is the “switching angle shift”, where the applied direct current is assumed to shift, via domain wall depinning during anti-domain expansion, the switching angle of a perpendicular magnetization in a linear proportional manner under a large rotating magnetic field. Here, we report that, for the most commonly employed perpendicular magnetization heterostructures in spintronics(e.g., those based on FeCoB, Co, and Co/Ni multilayers), the switching angle shift considerably misestimates the SOT within the domain wall depinning analysis of the slope of linear-in-current scaling and may also have a non-zero residual value at zero direct current. Our experiments and simulations unveil that the switching angle shift is most likely dominated by chiral asymmetric nucleation rather than expansion of anti-domains. The in-plane field from external magnets and current-induced SOTs lowers the perpendicular nucleation field and thus reduces the required switching angle, ultimately leading to an underestimation of SOTs by domain wall depinning analysis. These results have advanced our understanding of magnetization switching in spintronic devices.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3604203)the Key Research and Development Program of Guangdong Province,China(Grant No.2024B0101060002)the Key Research and Development Program of Shenzhen City,China(Grant No.JCYJ20241202130036043)。
文摘Research on p-channel field-effect transistors(p-FETs)remains limited,primarily due to the significantly lower conductivity of the two-dimensional hole gas(2DHG)compared to the two-dimensional electron gas(2DEG)in n-channel field-effect transistors(n-FETs),which poses a significant challenge for monolithic integration.In this study,we investigate the impact of epitaxial structure parameters on 2DHG properties in p-Ga N/Al Ga N/Ga N heterostructures through semiconductor technology computer-aided design(TCAD)simulations and theoretical calculations,identifying the conditions necessary to achieve high-density 2DHG.Our simulations demonstrate that increasing the p-Ga N thickness leads to two critical thicknesses determined by surface states and acceptor ionization concentration:one corresponds to the onset of 2DHG formation,and the other to its saturation.Lowering the donor surface state energy level and increasing the acceptor ionization concentration promote 2DHG formation and saturation,although the saturated density remains independent of surface states.Additionally,a higher Al composition enhances intrinsic ionization due to stronger polarization effects,thereby increasing the 2DHG sheet density.Consequently,to achieve high-density 2DHG in p-Ga N/Al Ga N/Ga N heterostructures,it is essential to increase the Al composition,ensure that the p-Ga N thickness exceeds the critical thickness for 2DHG saturation,and maximize the acceptor ionization concentration.This study elucidates the impact of epitaxial structure parameters on 2DHG properties in p-Ga N/Al Ga N/Ga N heterostructures and provides valuable guidance for the optimization of p-FET designs.
基金financially supported by the Natural Science Foundation of China(NSFC,No.22165032)Beijing Natural Science Foundation(No.2242032)
文摘The rational design of composition and microstructure is a proven strategy for developing multifunctional high-performance electromagnetic wave(EMW)absorbers.In this study,a sandwich-structured multilayer nanoplate-like Bi_(2)Fe_(4)O_(9)@Polypyrrole(BFO@PPy)heterostructure was successfully designed and fabricated using an efficient microwave hydrothermal method and an in situ polymerization process.Specifically,Bi_(2)Fe_(4)O_(9)enhances the chemical activity of ammonium persulfate,which in turn initiates the polymerization of pyrrole monomers,resulting in the formation of BFO@PPy heterostructures.The thickness of the PPy coating layer in the BFO@PPy composite can be precisely controlled at the nanoscale,optimizing electromagnetic parameters,conduction losses and interface polarization loss.The fabricated BFO@PPy composite achieves a minimum reflection loss(RL_(min))of-57.8 dB at a thickness of 2.5 mm and an effective absorption bandwidth(EAB)of 6.96 GHz.Furthermore,the EMW absorption performance and mechanism were systematically validated through theoretical calculations,radar cross-sectional simulations(RCS),and first-principles analysis.Notably,the RCS simulation of a 1:1 scale F-22 Raptor fighter model provides a realistic evaluation of the composite's EMW absorption potential in military applications.The efficient fabrication method and superior electromagnetic absorption performance make BFO@PPy a promising candidate for use in complex electromagnetic environments and military domains.Additionally,the BFO@PPy composite exhibits rapid electrothermal conversion at a low voltage(3V),achieving active infrared camouflage within a controllable temperature range,further highlighting its multifunctional properties.
基金the College Students Innovative Practice Fund of Jiangsu University Industrial Center(ZXJG2023047)for funding this research.
文摘Structured design helps to play out the coordination advantage and optimize the performance of electro-chemical reactions.In this work,hierarchical hollow microspheres(Co_(3)S_(4)@NiCo_(2)S_(4)) with unique core-shell heterostructure were successfully prepared through simple template and solvothermal methods.Thanks to the hollow structure,cross-linked nanowire arrays,and in-situ coating of zeolite imidazole framework(ZIF),Co_(3)S_(4)@NiCo_(2)S_(4) demonstrated excellent electrochemical performance with a specific ca-pacitance of up to 2697.7 F g^(-1)at 1 A g^(-1) and cycling stability of 80.5% after 5000 cycles.The covalent organic framework(COF)derived nano carbon,which had undergone secondary calcination and ZnCl_(2) activation,also exhibited excellent double-layer energy storage performance.Compared to a single calci-nation,the incredible increase in capacitance was up to 208.5 times greater,reaching 291.9 F g^(-1)at 1 A g^(-1)while maintaining ultra-high rate performance(81.0%at 20 A g^(-1)).The hybrid supercapacitor,assem-bled with Co_(3)S_(4)@NiCo_(2)S_(4)as the cathode and COF-derived carbon as the anode,exhibited an extremely high energy density(79.7 Wh kg^(-1)at 693.5 W kg^(-1))and excellent cyclic stability(maintained 79.3%after 10,000 cycles of 20 A g^(-1)),further explaining the reliable and practical characteristics.This work provided reference for the structural optimization of transition metal sulfides and the high-temperature activation of COF-derived carbon.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_0120)the National Natural Science Foundation of China(Nos.22275088 and 52101260)+3 种基金the Project of Shuangchuang Scholar of Jiangsu Province(No.JSSCBS20210212)the Fundamental Research Funds for the Central Universities(No.30921011203)the Start-Up Grant(No.AE89991/340)from Nanjing University of Science and Technology,the Foundation of Jiangsu Educational Committee(No.22KJB310008)the Senior Talent Program of Jiangsu University(No.20JDG073).
文摘The reduction of global carbon emissions and the achievement of carbon neutrality have become the focus of addressing climate change and global warming.Electrochemical CO_(2) reduction(CO_(2)RR),as a technology that can efficiently convert CO_(2) into value-added products,is receiving widespread attention.This article reviews the current research status of Cu/metal oxide heterostructures in the field of electrochemical reduction of CO_(2).The review first introduces the importance of electrochemical reduction of CO_(2) and the application potential of Cu/metal oxide heterostructures in this field.Subsequently,a comprehensive discussion is presented on the exploration of various Cu/metal oxide heterostructures and their corresponding structure-performance relationship,with particular emphasis on the catalysts'activity,selectivity,stability and the nature of active sites.Lastly,the review provides an overview of the current research challenges and future development trends in this field.
基金supported by the National Natural Science Foundation of China (No. 22305210, 52371238 to C. D.)the Shandong Provincial Natural Science Foundation (No. ZR2020QB108)+1 种基金the Graduate Innovation Foundation of Yantai University (GIFYTU)the Shandong Laboratory of Advanced Materials and Green Manufacturing (Yantai, AMGM2024A01)
文摘Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.
基金Project supported by the National Natural Science Foundation of China (Grant No. 92477205)。
文摘Controlling charge polarity in the semiconducting single-walled carbon nanotubes(CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is explored by filling CNTs with one-dimensional(1D)-TM_(6)Te_(6) nanowires to form TM_(6)Te_(6)@CNT-(16,0) 1D van der Waals heterostructures(1D-vd WHs). The systematic first-principles studies on the electronic properties of 1D-vd WHs show that N-type doping CNTs can be formed by charge transfer from TM_(6)Te_(6) nanowires to CNTs, without introducing additional carrier scattering.Particularly, contribution from both T M(e.g., Sc and Y) and Te atoms strengthens the charge transfer. The outside CNTs further confine the dispersion of Te-p orbitals in nanowires that deforms the C-π states at the bottom of the conduction band to quasi sp^(3) hybridization. Our study provides an inner doping strategy that can effectively confine the charge polarity of CNTs and further broaden its applications in some novel nano-devices.
基金Project supported by the National Key Research and Development Program of China(Grant No.2023YFF0719200)the National Natural Science Foundation of China(Grant Nos.62322115,U24A20226,61988102,and 62435010)+1 种基金the 111 Project(Grant No.D18014)the Science and Technology Commission of Shanghai Municipality(Grant Nos.22JC1400200 and 21S31907400)。
文摘The research on two-dimensional(2D)magnetic materials and their heterostructures is crucial in fields like spintronics,materials science,and condensed matter physics.This study uses terahertz(THz)time-domain spectroscopy to investigate ultrafast electron transport properties in both van der Waals Fe_(4)GeTe_(2)films and Bi_(2)Te_(3)/Fe_(4)GeTe_(2)ferromagnetic/topological heterostructures.Our results show that these heterostructures exhibit effective THz electromagnetic shielding.The complex conductivity spectra of Fe_(4)GeTe_(2)films and Bi_(2)Te_(3)/Fe_(4)GeTe_(2)heterostructures with varying Fe_(4)GeTe_(2)thicknesses are analyzed using the Drude-Smith model.We quantitatively examine how Fe_(4)GeTe_(2)layer thickness affects the direct current conductivity,plasma frequency,carrier momentum scattering time,and back-scattering coefficient.As the number of Fe_(4)GeTe_(2)layers increases,intra-layer back-scattering events for charge carriers become more frequent.This work provides THz frequency spectra for both Fe_(4)GeTe_(2)and Bi_(2)Te_(3)/Fe_(4)GeTe_(2),aiding in the design and optimization of THz modulators and detectors.
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 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supported by the Technology Innovation Program(RS-2024-00508071 and RS-2024-00416098)funded by the Ministry of Trade Industry&Energy(MOTIE,Korea)supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(RS-2022-NR072281)financial support from the Development of Smart Chemical Materials for IoT Devices Project(KS2521-10)through the Korea Research Institute of Chemical Technology.
文摘Constructing a nanostructure that combines abundant active edge sites with a well-designed heterostructure is an effective strategy for enhancing photocatalytic hydrogen generation.However,controllable approaches for creating heterostructures based on vertically standing transition metal dichalcogenide(TMD)nanosheets remain insufficient despite their potential for efficient hydrogen production.In this paper,we present efficient photocatalysts featuring heterojunctions composed of vertically grown TMD(MoS_(2)and WS_(2))nanosheets.These structures(WS_(2),MoS_(2),and MoS_(2)/WS_(2)heterostructure)were fabricated using a controllable metal–organic chemical vapor deposition method,which expanded the surface area and facilitated effective photocatalytic hydrogen evolution.The vertical MoS_(2)/WS_(2)heterostructures demonstrated significantly enhanced hydrogen generation,driven by the synergistic effects of improved light absorption,a large specific surface area,and appropriately arranged staggered heterojunctions.Furthermore,the photocatalytic activity was considerably influenced by the size and density of the vertical nanosheets.Consequently,the nanosheet size-tailored MoS_(2)/WS_(2)heterostructure achieved a photocatalytic hydrogen generation rate(454.2μmol h^(–1) cm^(–2)),which is 2.02 times and 2.19 times higher than that of WS_(2)(225.6μmol h^(-1) cm^(-2))and MoS_(2)(207.2μmol h^(–1) cm^(–2)).Hence,the proposed strategy can be used to design staggered heterojunctions with edge-rich nanosheets for photocatalytic applications.
基金the financial support by the National Key Research and Development Program of China(No.2019YFA0708700)the National Natural Science Foundation of China(Nos.62305196,U23B2087 and 62375158)+4 种基金the China Postdoctoral Science Foundation(No.GZC20231498)the Qingdao Postdoctoral Innovation Project(No.QDBSH20240102078)the Postdoctoral Innovation Program of Shandong Province(No.SDCX-ZG-202400318)Science and Technology Research Project of Hubei Provincial Department of Education(No.D20212603)Hubei University of Arts and Science(No.2020kypytd002)。
文摘Surface adsorption plays a crucial role in various natural and industrial processes,particularly in the field of energy storage.The adsorption of sodium atoms on 2D layered materials can significantly impact their performance as carriers and electrodes in ion batteries.While it is commonly acknowledged that pristine graphene is not favorable for sodium ion adsorption,the suitability of other 2D materials with similar honeycomb symmetry remains unclear.In this study,we employ systematic first-principles calculations to explore interlayer interactions and electron transfer effects on sodium adsorption on 2D van der Waals(vdW)heterostructures(HTSs)surfaces.Our results demonstrate that sodium adsorption is energetically favorable on these substrates.Moreover,we find that the adsorption strength can be effectively tuned by manipulation of the electron accumulation or depletion of the layer directly interacting with the sodium atom.By stacking these layered materials with different electron abundancy to form vd W HTSs,the charge density of the substrate becomes tunable through interlayer charge transfer.In these vdW HTSs,the adsorption behavior of sodium is primarily controlled by the absorption layer and exhibits a linear correlation with its pz-band center.Additionally,we identify linear correlations between the sodium adsorption energies,the electron loss of the sodium atom,the interlayer charge transfer,and the heights of the adsorbed sodium atom.These discoveries underscore the impact of interlayer electron transfer and interactions on sodium ion adsorption on 2D vd W HTSs and providing new insights into material design for alkali atom adsorption.
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support from the NSFC(Nos.91622114,21520102001,21521061 and 21331006)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(No.SKLPEE-202008)Fuzhou University,and the Special Fund for Scientific and Technological Innovation of Fujian Agriculture and Forestry University(No.CXZX2019073G).
文摘Photocatalytic conversion of chemical fuels has emerged as a most challenging subject in photocatalysis which is considered as one of the sustainable solutions for environmental issues related to the energy shortage and anthropogenic carbon emissions.Herein,unique heterostructures of ZnCdS nanoplates with Bi_(2)S_(3)-terminated edges were prepared through a facile cation exchange pathway,by which the controlled photocatalytic CO_(2)conversion was achieved.The optimized BZCS–NS-5 photocatalyst exhibited an excellent capacity of CO_(2)photoreduction with a CO production rate of ca.513.2-5.1μmol g^(-1)h^(-1)and a selectivity of ca.91.0%,which were among the highest activities for sulfide photocatalysts documented in the literature.The outstanding photocatalytic performance was attributable to the formation of Z-scheme heterostrucutres between Bi_(2)S_(3)and ZnCdS,in a way the separation and migration of photocarriers were accelerated.This work thus provides a feasible strategy for the construction of heterostructures to enhance the activity and selectivity of CO_(2)-to-CO conversion via delicate design and controlled synthesis of photocatalysts.
