Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical...Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.展开更多
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
Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics...Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics,and free electron radiation devices.Particularly,they are promising platforms for studying thermionic emission.It is illustrated that using vdW heterostructure-based thermionic emission can enhance heat transfer in vacuum devices.As a proof of concept,the approach is demonstrated to offer a promising solution for the long-standing overheating issue in X-ray tubes.Specifically,it is shown that the saturated target temperature of a 2000 W X-ray tube can be reduced from around 1200℃ to 490℃.Additionally,it is also demonstrated that by reducing the height of the Schottky barrier formed in the vdW heterostructures,the thermionic cooling performance can be enhanced.The findings pave the way for the development of high-power X-ray tubes.展开更多
Recurrence of solid tumors after surgical resection is a major barrier to tissue regeneration.As an emerging treatment strategy,photo-thermo-electric therapy ablates tumor cells via photothermal effects and generates ...Recurrence of solid tumors after surgical resection is a major barrier to tissue regeneration.As an emerging treatment strategy,photo-thermo-electric therapy ablates tumor cells via photothermal effects and generates reactive oxygen species(ROS)via thermoelectric effects to disrupt heat shock proteins,thereby suppressing their protective function in tumor cells.However,conventional materials suffer from low thermoelectric efficiency and weak tissue penetration ability.In this study,we fabricated iodine-doped bismuth sulfide(I-Bi_(2)S_(3))nanorods with bonding heterostructures to improve thermoelectric performance.The approach employed iodine doping to introduce additional electrons,thereby regulating the band structure of Bi_(2)S_(3)and exploiting the dual low-energy vibration effect of the heterostructures to reduce thermal conductivity.More importantly,controlling the type of heterostructure modulated the bandgap width,thereby expanding the light absorption range to the higher-penetration near-infrared(NIR)-Ⅱregion for deep tissue treatment.The I-Bi_(2)S_(3)nanorods were incorporated into poly-L-lactic acid(PLLA)scaffolds to confer antitumor functionality.According to the results,the bonding heterostructures enhanced the conductivity of Bi_(2)S_(3)and reduced its thermal conductivity,significantly enhancing thermoelectric efficacy.The heterostructures reduced the bandgap of Bi_(2)S_(3)from 1.23 to 0.88 eV,enabling optical absorption in the NIR-Ⅱregion.The ROS tests showed that the PLLA/I-Bi_(2)S_(3)scaffold exhibited good photothermal effects and ROS generation under 1064-nm laser irradiation.The antitumor efficacy of the PLLA/I-Bi_(2)S_(3)scaffold reached 84.6%against MG-63 cells,demonstrating its exceptional potential in cancer treatment.展开更多
The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexit...The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexity of NO_(3)^(−)RR,yet challenges remain in optimizing performance and elucidating tandem mechanisms.Herein,we report a Cu@Co/CoFe-P tandem electrocatalyst featuring a phosphorus-doped heterostructure with dual active sites(Cu-P and Co/CoFe-P).This catalyst achieves an exceptional NH_(3)yield of 175.40 mg h^(−1)cm^(−2)and a record-high current density exceeding 2 A cm^(−2),with the electro-synthesized NH3 directly converted into NH4Cl.In situ spectroscopic analysis and density functional theory(DFT)calculations reveal a novel desorption-reactivation tandem mechanism:(1)the Cu-P domain preferentially reduces NO_(3)^(−)to*NO_(2),which desorbs as stable NO_(2)^(−);(2)the Co/CoFe-P domain subsequently reactivates NO_(2)^(−),and converts it efficiently into NH3.Moreover,phosphorus doping enhances*H supply,while Fe alloying with Co promotes NO_(2)^(−)hydrogenation,ensuring an efficient and synchronized tandem pathway for NO_(3)^(−)RR.The proposed*NO_(2)desorption-reactivation mechanism deepens the understanding of NO_(3)^(−)RR tandem process,thereby paving the way for designing more efficient tandem electrocatalysts.展开更多
Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promisin...Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promising strategy to address this issue.To realize the synergy,herein,Sn whiskers with an in situ oxide layer served as substrates for magnetic-loss-active CoNi nanosheet growth,forming a hierarchical CoNi@SnO_(2)@Sn(CNS)heterostructure.The CNS absorber achieves a minimum reflection loss(RL_(min))value of-62.29 dB with an effective absorption bandwidth(EAB)of 2.2 GHz,covering the entire C-band with 70%absorption at only 2.61 mm thickness.The nanosheet design of CoNi enhances magnetic anisotropy to promote natural resonance,while the conductive Sn core and abundant Sn/SnO_(2) and CoNi/SnO_(2) heterointerfaces facilitate conduction loss and dielectric polarization.When composited into a thermoplastic polyurethane(TPU)matrix,the resulting CNS/TPU-2 film(20 wt%CNS)exhibits an RL_(min) value of-61.04 dB and a 2.5 GHz EAB.Its in-plane and through-plane thermal conductivities reach 2.41 and 0.51 W m^(-1) K^(-1),representing 4.1 and 2.6 times those of pure TPU films,respectively,facilitating heat dissipation from protected devices.This work provides valuable insights into magnetic-dielectric synergy for low-frequency MA of 1D metal-based materials,offering promising potential for 5G communications and flexible electronics.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
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 large volume expansion and rapid capacity attenuation of tin-based electrodes are the main factors limiting their commercial application.The reasonable design of electrode material structure is particularly import...The large volume expansion and rapid capacity attenuation of tin-based electrodes are the main factors limiting their commercial application.The reasonable design of electrode material structure is particularly important for improving its electrochemical performance.Herein,phosphorus-modified graphene encapsulated Sn_(6)O_(4)(OH)_(4)nanoparticles composite(P-Sn_(6)O_(4)(OH)_(4)@RGO)with crystalline-amorphous heterostructure has been successfully designed and prepared.The design of crystalline-amorphous structure has largely enhanced the active sites,and the construction of a graphene encapsulation structure has greatly alleviated volume expansion.Notably,P-Sn_(6)O_(4)(OH)_(4)@RGO obtained an excellent high-rate longterm cycling performance for lithium-ion batteries anode,reaching a high specific capacity of 970 m Ah/g at 1.0 A/g after 1450 cycles.This work demonstrates that restructuring the electrode material's structure and phase through phosphorus modification can effectively improve the electrochemical performance of tin-based electrode materials.展开更多
The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we re...The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we report a high-performanee dual-channel phototransistor based on one-dimensional (1D)/two-dimensional (2D) trigonal selenium (t-Se)/ReS2 heterostructures grown by chemical vapor deposition. The injection and separati on efficie ncy of photoge nerated electro n-hole pairs can be greatly improved due to the high-quality in terfacial con tact betwee n t-Se nano belts and ReS2 films. Compared with bare ReS2 film devices, the dual-cha nnel phototra nsistor based on t-Se/ReS2 heterostructure exhibits considerable enhancement with the responsivity (R) and detectivity (D^*) up to 98 A·W^-1 and 6 x 10^10 Jones at 400 nm illumination with an in tensity of 1.7 mW·cm^-2, respectively. Besides, the respo nse time can also be reduced by three times of magnitude to less than 50 ms due to the type-11 band alignment at the in terface. This study opens up a promising ave nue for high-performa nee photodetectors by constructing mixed-dimensional heterostructures.展开更多
The low separation efficiency of the photogenerated carrier and the poor activity of the surface redox reaction are the main barrier to further improvement of photocatalytic materials.To address these issues,introduci...The low separation efficiency of the photogenerated carrier and the poor activity of the surface redox reaction are the main barrier to further improvement of photocatalytic materials.To address these issues,introducing spin-polarized electrons in single-component photocatalytic materials emerged as a promising approach.However,the decreased redox ability of photocarriers in these materials becomes a new challenge.Herein,we mitigate this challenge with a carbon nitride sheet(CNs)/graphene nanoribbon(GNR)composite material that has a van der Waals heterostructures(vdWHs)and spin-polarized electron properties.Experimental results and theoretical calculations show that the heterostructure has a strong redox ability,high carrier-separation efficiency,and enhanced surface catalytic reaction.Consequently,the mixed-dimensional CNs/GNR vdWHs exhibit remarkable performance for H_(2)and O_(2)generation as well as CO_(2)production under visible-light irradiation without any cocatalyst.The spin-polarized vdWHs discovered in this study revealed a new type of photocatalytic materials and advanced the development of spintronics and photocatalysis.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
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
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
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
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
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
1.Introduction.The Ti6Al4V alloy is extensively utilized across various indus-trial sectors due to its favorable characteristics,such as lightweight design,high strength,and resistance to corrosion[1].In effort s to f...1.Introduction.The Ti6Al4V alloy is extensively utilized across various indus-trial sectors due to its favorable characteristics,such as lightweight design,high strength,and resistance to corrosion[1].In effort s to further reduce weight,functional elements like electric actuators can be substituted with intelligent materials like shape memory alloys(SMAs)[2,3].Among SMAs,NiTi alloy stands out for its sens-ing and actuation capabilities,significantly enhancing the safety and reliability of engineering structures[4,5].Integrating Ti6Al4V and NiTi alloys within a single component holds the potential to provide precise feedback on mechanical,thermal,or environmen-tal conditions[6,7].展开更多
基金the financial support from the Research Grants Council of Hong Kong(No.15304519)the National Natural Science Foundation of China(No.11904306)+2 种基金the Hong Kong Polytechnic University(No.1-ZVH9)The authors also thank the Fundamental Research Funds for the Central Universities(Nos.2019B02414 and 2019B44214)PAPD,and Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering,MOE(No.KLIEEE-18-02).
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDCs)are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical,chemical,electronic,and optical properties.This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering.First,we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination.We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures.Further,we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts,particularly focusing on synthesis routes,modification approaches,and physiochemical mechanisms for improving their photoactivity.Finally,we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.
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supported by National Natural Science Foundation of China(61921002 and 92163204)。
文摘Van der Waals(vdW)heterostructures have attracted much attention due to their distinctive optical,electrical,and thermal properties,demonstrating promising potential in areas such as photocatalysis,ultrafast photonics,and free electron radiation devices.Particularly,they are promising platforms for studying thermionic emission.It is illustrated that using vdW heterostructure-based thermionic emission can enhance heat transfer in vacuum devices.As a proof of concept,the approach is demonstrated to offer a promising solution for the long-standing overheating issue in X-ray tubes.Specifically,it is shown that the saturated target temperature of a 2000 W X-ray tube can be reduced from around 1200℃ to 490℃.Additionally,it is also demonstrated that by reducing the height of the Schottky barrier formed in the vdW heterostructures,the thermionic cooling performance can be enhanced.The findings pave the way for the development of high-power X-ray tubes.
基金National Key Research and Development Program of China(No.2023YFB4605800)The National Natural Science Foundation of China(Nos.52475362,52365046,and 52465041)+3 种基金Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)Jiangxi Provincial Key Laboratory of Additive Manufacturing of Implantable Medical Device(No.2024SSY11161)Jiangxi Provincial Department of Education Science and Technology Project(No.GJJ2400708)Jiangxi Province Science and Technology Program(Nos.20252BAC200317 and 20252BEJ730195)。
文摘Recurrence of solid tumors after surgical resection is a major barrier to tissue regeneration.As an emerging treatment strategy,photo-thermo-electric therapy ablates tumor cells via photothermal effects and generates reactive oxygen species(ROS)via thermoelectric effects to disrupt heat shock proteins,thereby suppressing their protective function in tumor cells.However,conventional materials suffer from low thermoelectric efficiency and weak tissue penetration ability.In this study,we fabricated iodine-doped bismuth sulfide(I-Bi_(2)S_(3))nanorods with bonding heterostructures to improve thermoelectric performance.The approach employed iodine doping to introduce additional electrons,thereby regulating the band structure of Bi_(2)S_(3)and exploiting the dual low-energy vibration effect of the heterostructures to reduce thermal conductivity.More importantly,controlling the type of heterostructure modulated the bandgap width,thereby expanding the light absorption range to the higher-penetration near-infrared(NIR)-Ⅱregion for deep tissue treatment.The I-Bi_(2)S_(3)nanorods were incorporated into poly-L-lactic acid(PLLA)scaffolds to confer antitumor functionality.According to the results,the bonding heterostructures enhanced the conductivity of Bi_(2)S_(3)and reduced its thermal conductivity,significantly enhancing thermoelectric efficacy.The heterostructures reduced the bandgap of Bi_(2)S_(3)from 1.23 to 0.88 eV,enabling optical absorption in the NIR-Ⅱregion.The ROS tests showed that the PLLA/I-Bi_(2)S_(3)scaffold exhibited good photothermal effects and ROS generation under 1064-nm laser irradiation.The antitumor efficacy of the PLLA/I-Bi_(2)S_(3)scaffold reached 84.6%against MG-63 cells,demonstrating its exceptional potential in cancer treatment.
基金supported financially by the Key Project of the National Ministry of Science and Technology (No.2022YFC3705005)the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering,MOE (KLIEEE-22-05)
文摘The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexity of NO_(3)^(−)RR,yet challenges remain in optimizing performance and elucidating tandem mechanisms.Herein,we report a Cu@Co/CoFe-P tandem electrocatalyst featuring a phosphorus-doped heterostructure with dual active sites(Cu-P and Co/CoFe-P).This catalyst achieves an exceptional NH_(3)yield of 175.40 mg h^(−1)cm^(−2)and a record-high current density exceeding 2 A cm^(−2),with the electro-synthesized NH3 directly converted into NH4Cl.In situ spectroscopic analysis and density functional theory(DFT)calculations reveal a novel desorption-reactivation tandem mechanism:(1)the Cu-P domain preferentially reduces NO_(3)^(−)to*NO_(2),which desorbs as stable NO_(2)^(−);(2)the Co/CoFe-P domain subsequently reactivates NO_(2)^(−),and converts it efficiently into NH3.Moreover,phosphorus doping enhances*H supply,while Fe alloying with Co promotes NO_(2)^(−)hydrogenation,ensuring an efficient and synchronized tandem pathway for NO_(3)^(−)RR.The proposed*NO_(2)desorption-reactivation mechanism deepens the understanding of NO_(3)^(−)RR tandem process,thereby paving the way for designing more efficient tandem electrocatalysts.
基金supported by the National Natural Science Foundation of China(52171033,52431003,U23A20574)the Fundamental Research Funds for the Central Universities(2242025K20004)the SEU Innovation Capability Enhancement Plan for Doctoral Students(CXJH_SEU 24148,CXJH_SEU 25036).
文摘Microwave absorption(MA)materials often face poor synergy between impedance matching and attenuation in the low-frequency range.Balancing permittivity and permeability through magnetic-dielectric synergy is a promising strategy to address this issue.To realize the synergy,herein,Sn whiskers with an in situ oxide layer served as substrates for magnetic-loss-active CoNi nanosheet growth,forming a hierarchical CoNi@SnO_(2)@Sn(CNS)heterostructure.The CNS absorber achieves a minimum reflection loss(RL_(min))value of-62.29 dB with an effective absorption bandwidth(EAB)of 2.2 GHz,covering the entire C-band with 70%absorption at only 2.61 mm thickness.The nanosheet design of CoNi enhances magnetic anisotropy to promote natural resonance,while the conductive Sn core and abundant Sn/SnO_(2) and CoNi/SnO_(2) heterointerfaces facilitate conduction loss and dielectric polarization.When composited into a thermoplastic polyurethane(TPU)matrix,the resulting CNS/TPU-2 film(20 wt%CNS)exhibits an RL_(min) value of-61.04 dB and a 2.5 GHz EAB.Its in-plane and through-plane thermal conductivities reach 2.41 and 0.51 W m^(-1) K^(-1),representing 4.1 and 2.6 times those of pure TPU films,respectively,facilitating heat dissipation from protected devices.This work provides valuable insights into magnetic-dielectric synergy for low-frequency MA of 1D metal-based materials,offering promising potential for 5G communications and flexible electronics.
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 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supported by the Natural Science Foundation of Shandong Province(Nos.ZR2024QE450,ZR2024QB302 and ZR2024QB004)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202211249)Research Program of Qilu Institute of Technology(Nos.QIT 23TP019,QIT23TP010 and QIT24NN007)。
文摘The large volume expansion and rapid capacity attenuation of tin-based electrodes are the main factors limiting their commercial application.The reasonable design of electrode material structure is particularly important for improving its electrochemical performance.Herein,phosphorus-modified graphene encapsulated Sn_(6)O_(4)(OH)_(4)nanoparticles composite(P-Sn_(6)O_(4)(OH)_(4)@RGO)with crystalline-amorphous heterostructure has been successfully designed and prepared.The design of crystalline-amorphous structure has largely enhanced the active sites,and the construction of a graphene encapsulation structure has greatly alleviated volume expansion.Notably,P-Sn_(6)O_(4)(OH)_(4)@RGO obtained an excellent high-rate longterm cycling performance for lithium-ion batteries anode,reaching a high specific capacity of 970 m Ah/g at 1.0 A/g after 1450 cycles.This work demonstrates that restructuring the electrode material's structure and phase through phosphorus modification can effectively improve the electrochemical performance of tin-based electrode materials.
基金National Natural Science Foundation of China (Nos. 51572057 and 51772064)AFOSR/NSF EFRI 2DARE program, ARO and SRC.
文摘The com bination of mixed-dimensional semiconducti ng materials can provide additional freedom to construct integrated n anoscale electronic and optoelectronic devices with diverse functionalities. In this work, we report a high-performanee dual-channel phototransistor based on one-dimensional (1D)/two-dimensional (2D) trigonal selenium (t-Se)/ReS2 heterostructures grown by chemical vapor deposition. The injection and separati on efficie ncy of photoge nerated electro n-hole pairs can be greatly improved due to the high-quality in terfacial con tact betwee n t-Se nano belts and ReS2 films. Compared with bare ReS2 film devices, the dual-cha nnel phototra nsistor based on t-Se/ReS2 heterostructure exhibits considerable enhancement with the responsivity (R) and detectivity (D^*) up to 98 A·W^-1 and 6 x 10^10 Jones at 400 nm illumination with an in tensity of 1.7 mW·cm^-2, respectively. Besides, the respo nse time can also be reduced by three times of magnitude to less than 50 ms due to the type-11 band alignment at the in terface. This study opens up a promising ave nue for high-performa nee photodetectors by constructing mixed-dimensional heterostructures.
基金supported by the National Natural Science Foundation of China(Grant No.12104352 and 51973170)Fundamental Research Funds for the Central Universities(Grant No.XJS212208 and 2020BJ-56)+1 种基金Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2022-K67)the National Natural Science Foundation of Shaanxi Province under Grant No.2019JCW-17 and 2020JCW-15.
文摘The low separation efficiency of the photogenerated carrier and the poor activity of the surface redox reaction are the main barrier to further improvement of photocatalytic materials.To address these issues,introducing spin-polarized electrons in single-component photocatalytic materials emerged as a promising approach.However,the decreased redox ability of photocarriers in these materials becomes a new challenge.Herein,we mitigate this challenge with a carbon nitride sheet(CNs)/graphene nanoribbon(GNR)composite material that has a van der Waals heterostructures(vdWHs)and spin-polarized electron properties.Experimental results and theoretical calculations show that the heterostructure has a strong redox ability,high carrier-separation efficiency,and enhanced surface catalytic reaction.Consequently,the mixed-dimensional CNs/GNR vdWHs exhibit remarkable performance for H_(2)and O_(2)generation as well as CO_(2)production under visible-light irradiation without any cocatalyst.The spin-polarized vdWHs discovered in this study revealed a new type of photocatalytic materials and advanced the development of spintronics and photocatalysis.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52171206 and52271209)Key Project of Hebei Natural Science Foundation(Nos.F2024201031 and E20202201030)+4 种基金Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project(No.21344301D)the Second Batch of Young Talent of Hebei Province(Nos.70280016160250 and 70280011808)Key Fund in Hebei Province Department of Education China(No.ZD2021014)the Central Government Guide Local Funding Projects for Scientific and Technological Development(Nos.216Z4404G and 206Z4402G)Interdisciplinary Research Program of Natural Science of Hebei University(No.DXK202107)。
文摘The lithium-oxygen battery(LOB)is a promising source of green energy due to its energy density.However,the development of this technology is limited by the insoluble discharge product it produces.In this work,a cathode material with a p-n heterostructure of polyaniline(PANI)/ZnS is prepared to trap visible light,utilizing a ZnS quantum dot(ZnS QD)network to form a large number of photogenerated electron–hole pairs,thus promoting the generation and decomposition of Li_(2)O_(2).The prepared PANI/ZnS has an ultra-low overpotential of 0.06 V under illumination.Furthermore,density functional theory theoretical calculation has demonstrated the ability of the heterostructures to adsorb oxygen-containing intermediates,which not only facilitates the growth of Li_(2)O_(2),but also reduces the reaction energy required to decompose Li_(2)O_(2).The present work provides a solution to the problem of insolubility of discharge products in photo-assisted LOB.
基金supported by the 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 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 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supported by the National Natural Science Foundation of China(Grant No.52235006)the National Key Research and Development Program of China(Grant No.2022YFB4600500)+3 种基金the National Natural Science Foundation of China(Grant Nos.52025053 and 52105303)the Natural Science Foundation of Jilin Province(Grant No.20220101209JC)the Postdoctoral Fellow-ship Program of CPSF(Grant GZC20240587 and GZC20230944)the Graduate Innovation Fund of Jilin University(2024CX063).
文摘1.Introduction.The Ti6Al4V alloy is extensively utilized across various indus-trial sectors due to its favorable characteristics,such as lightweight design,high strength,and resistance to corrosion[1].In effort s to further reduce weight,functional elements like electric actuators can be substituted with intelligent materials like shape memory alloys(SMAs)[2,3].Among SMAs,NiTi alloy stands out for its sens-ing and actuation capabilities,significantly enhancing the safety and reliability of engineering structures[4,5].Integrating Ti6Al4V and NiTi alloys within a single component holds the potential to provide precise feedback on mechanical,thermal,or environmen-tal conditions[6,7].
