Based on first-principles density functional theory calculation,we discover a novel form of spin-orbit(SO)splitting in two-dimensional(2D)heterostructures composed of a single Bi(111)bilayer stacking with a 2D semicon...Based on first-principles density functional theory calculation,we discover a novel form of spin-orbit(SO)splitting in two-dimensional(2D)heterostructures composed of a single Bi(111)bilayer stacking with a 2D semiconducting In_(2)Se_(2) or a 2D ferroelectricα-In_(2)Se_(3) layer.Such SO splitting has a Rashba-like but distinct spin texture in the valence band around the maximum,where the chirality of the spin texture reverses within the upper spin-split branch,in contrast to the conventional Rashba systems where the upper branch and lower branch have opposite chirality solely in the region below the band crossing point.The ferroelectric nature ofα-In_(2)Se_(3) further enables the tuning of the spin texture upon the reversal of the electric polarization with the application of an external electric field.Detailed analysis based on a tight-binding model reveals that such SO splitting texture results from the interplay of complex orbital characters and substrate interaction.This finding enriches the diversity of SO splitting systems and is also expected to promise for spintronic applications.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
Polarization-induced two-dimensional hole gases(2DHG)in GaN/AlGaN/GaN heterostructures offer a promising pathway for advancing p-channel transistors.This work investigates the impact of p-GaN thickness on hole distrib...Polarization-induced two-dimensional hole gases(2DHG)in GaN/AlGaN/GaN heterostructures offer a promising pathway for advancing p-channel transistors.This work investigates the impact of p-GaN thickness on hole distribution and transport through temperature-dependent Hall measurements and TCAD simulations.It is demonstrated that the p-channel is composed of holes both in the p-GaN layer and in the 2DHG at the GaN/AlGaN heterointerface at 300 K,whereas at 77 K,the p-channel conduction is dominated solely by the 2DHG at the GaN/AlGaN heterointerface.The results also reveal the formation of a polarization-induced 2DHG at the GaN/AlGaN interface,exhibiting a high sheet density of 2.2×10^(13)cm^(-2)and a mobility of 16.2 cm^(2)·V^(-1)·s^(-1)at 300 K.The 2DHG sheet density remains nearly independent of p-GaN thickness when the p-GaN layer exceeds 30 nm.However,for p-GaN layers thinner than 30 nm,the 2DHG sheet density strongly depends on the p-GaN thickness,which is attributed to the gradual extension of the depletion region toward the GaN/AlGaN interface under the influence of surface trap states.展开更多
Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydr...Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydrothermal reactions or molten salt-assisted strategies make it challenging to directly assess charge distribution and evaluate a single interface's hydrogen evolution reaction(HER)performance.Here,we prepared two-dimensional MoO_(2)/MoS_(2) step heterostructures with a large specific surface area by the chemical vapor deposition method.Surface Kelvin probe force microscopy and electrical transport measurement verified the asymmetric charge distribution at a single interface.By fabricating a series of micro on-chip electrocatalytic devices,we investigate the HER performance for a single interface and confirm that the interface is essential for superior catalytic performance.We experimentally confirmed that the enhancement of the HER performance of step heterostructure is attributed to the asymmetric charge distribution at the interface.This work lays a foundation for designing highly efficient catalytic systems based on step heterostructures.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
Two-dimensional(2D)materials,due to its excellent mechanical,unique electrical and optical properties,have become hot materials in the field of photocatalysis.Especially,2D heterostructures can well inhibit the recomb...Two-dimensional(2D)materials,due to its excellent mechanical,unique electrical and optical properties,have become hot materials in the field of photocatalysis.Especially,2D heterostructures can well inhibit the recombination of photogenerated electrons and holes in photocatalysis because of its special energy band structures and carrier transport characteristics,which are conducive to enhancing photoenergy conversion capacity and improving oxidation and reduction ability,so as to purify pollutants and store energy.In this minireview,we summarize recent theoretical progress in direct Z-scheme photocatalysis of 2D heterostructures,focusing on physical mechanism and improving catalytic efficiency.Current challenges and prospects for 2D direct Z-scheme photocatalysts are discussed as well.展开更多
Magnetotransport properties of two-dimensional electron gases （2DEG） in AlxGa1-x N/GaN heterostructures with different Al compositions are investigated by magnetotransport measurements at low temperatures and in hig...Magnetotransport properties of two-dimensional electron gases （2DEG） in AlxGa1-x N/GaN heterostructures with different Al compositions are investigated by magnetotransport measurements at low temperatures and in high magnetic fields. It is found that heterostructures with a lower Al composition in the barrier have lower 2DEG concentration and higher 2DEG mobility.展开更多
Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a no...Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.展开更多
Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupli...Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupling,and 1T-VTe_(2)monolayer theoretically predicted to host an intrinsic magnetism as experimentally suggested.In this work,we successfully constructed a vertical heterostructure composed of the two-dimensional Bi(110)monolayer and 1T-VTe_(2)monolayer by using molecular beam epitaxy(MBE).Scanning tunneling microscopy(STM)measurements revealed that the growth of Bi preferably occurs along the step edges of the VTe_(2)monolayer,forming a Bi(110)monolayer on top of the VTe_(2)monolayer next to a peripheral Bi bilayer.The Bi(100)/VTe_(2)heterostructure exhibits a specific lattice registry with a well-defined moiréperiodicity.Scanning tunneling spectroscopy(STS)measurements further unveiled an universal suppression in the local density-of-states at the boundary of the Bi(110)/VTe_(2)bilayer.By examining the atomic structures of Bi(110)boundaries,we found this effect does not originate from the previously proposed atomic reconstruction at the step edge of Bi(110),but is likely related to the magnetic properties of the VTe_(2)monolayer.展开更多
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
As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and el...As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.展开更多
Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of a...Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.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
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
Hydrogen production by photoelectrochemical(PEC) water splitting converts the inexhaustible supply of solar radiation to storable H2 as clean energy and thus has received widespread attention.The efficiency of PEC wat...Hydrogen production by photoelectrochemical(PEC) water splitting converts the inexhaustible supply of solar radiation to storable H2 as clean energy and thus has received widespread attention.The efficiency of PEC water splitting is largely determined by the properties of the photoelectrodes.Two-dimensional(2 D) layered transition metal dichalcogenides(TMDs) are promising candidates for photoelectrodes due to their atomic layer thickness,tunable bandgap,large specific surface area,and high carrier mobility.Moreover,the construction of 2 D TMDs heterostructures provides freedom in material design,which facilitates the further improvement of PEC water splitting.This review begins by describing the mechanism of PEC water splitting and the advantages of 2 D TMDbased heterostructures for photo electrodes.Then,the design considerations of the heterostructures for enhanced PEC efficiency are comprehensively reviewed with a focus on material selection,band engineering,surface modification,and long-term durability.Finally,current challenges and future perspectives for the development of photoelectrodes based on 2 D TMDs heterostructures are addressed.展开更多
Regarding the reverse process of materials growth,etching has been widely concerned to indirectly probe the growth kinetics,offering an avenue in governing the growth of two-dimensional(2D)materials.In this work,inter...Regarding the reverse process of materials growth,etching has been widely concerned to indirectly probe the growth kinetics,offering an avenue in governing the growth of two-dimensional(2D)materials.In this work,interface-driven anisotropic etching mode is demonstrated for the first time to be generally applied to 2D heterostructures.It is shown that the typical in-plane graphene and hexagonal boron nitride(h-BN)heterostructures follow a multi-stage etching behavior initiated first along the interfacial region between the two materials and then along edges of neighboring h-BN flakes and finally along central edges of hBN.By accurately tuning etching conditions in the chemical vapor deposition process,series of etched 2D heterostructure patterns are controllably produced.Furthermore,scaled formation of graphene and h-BN heterostructures arrays has been realized with full assist of as-proposed etching mechanism,offering a direct top-down method to make 2D orientated heterostructures with order and complexity.Detection of interface-driven multi-staged anisotropic etching mode will shed light on understanding growth mechanism and further expanding wide applications of 2D heterostructures.展开更多
基金Project supported by the Science Fund from the Ministry of Science and Technology of China(Grant Nos.2017YFA0204904 and 2019YFA0210004)the National Natural Science Foundation of China(Grant Nos.11674299 and 11634011)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)the Fund of Anhui Initiative Program in Quantum Information Technologies(Grant No.AHY170000)the Fundamental Research Funds for the Central Universities,China(Grant No.WK3510000013).
文摘Based on first-principles density functional theory calculation,we discover a novel form of spin-orbit(SO)splitting in two-dimensional(2D)heterostructures composed of a single Bi(111)bilayer stacking with a 2D semiconducting In_(2)Se_(2) or a 2D ferroelectricα-In_(2)Se_(3) layer.Such SO splitting has a Rashba-like but distinct spin texture in the valence band around the maximum,where the chirality of the spin texture reverses within the upper spin-split branch,in contrast to the conventional Rashba systems where the upper branch and lower branch have opposite chirality solely in the region below the band crossing point.The ferroelectric nature ofα-In_(2)Se_(3) further enables the tuning of the spin texture upon the reversal of the electric polarization with the application of an external electric field.Detailed analysis based on a tight-binding model reveals that such SO splitting texture results from the interplay of complex orbital characters and substrate interaction.This finding enriches the diversity of SO splitting systems and is also expected to promise for spintronic applications.
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 Key Research and Development Program of China(Grant No.2024YFE0205000)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20243037)+2 种基金the National Natural Science Foundation of China(Grant Nos.62074077 and 61921005)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20231098)the Collab-orative Innovation Center of Solid State Lighting and Energy-Saving Electronics.
文摘Polarization-induced two-dimensional hole gases(2DHG)in GaN/AlGaN/GaN heterostructures offer a promising pathway for advancing p-channel transistors.This work investigates the impact of p-GaN thickness on hole distribution and transport through temperature-dependent Hall measurements and TCAD simulations.It is demonstrated that the p-channel is composed of holes both in the p-GaN layer and in the 2DHG at the GaN/AlGaN heterointerface at 300 K,whereas at 77 K,the p-channel conduction is dominated solely by the 2DHG at the GaN/AlGaN heterointerface.The results also reveal the formation of a polarization-induced 2DHG at the GaN/AlGaN interface,exhibiting a high sheet density of 2.2×10^(13)cm^(-2)and a mobility of 16.2 cm^(2)·V^(-1)·s^(-1)at 300 K.The 2DHG sheet density remains nearly independent of p-GaN thickness when the p-GaN layer exceeds 30 nm.However,for p-GaN layers thinner than 30 nm,the 2DHG sheet density strongly depends on the p-GaN thickness,which is attributed to the gradual extension of the depletion region toward the GaN/AlGaN interface under the influence of surface trap states.
基金National Natural Science Foundation of China,Grant/Award Numbers:52288102,52090022,62274087,52472306Science Research Project of Hebei Education Department,Grant/Award Number:BJ2021040Natural Science Foundation of Hebei Province of China,Grant/Award Numbers:E2024203054,E2022203109。
文摘Step heterostructures are predicted to hold a profound catalytic performance because of the rearranged electronic structure at their interface.However,limitations in the morphology of heterostructures prepared by hydrothermal reactions or molten salt-assisted strategies make it challenging to directly assess charge distribution and evaluate a single interface's hydrogen evolution reaction(HER)performance.Here,we prepared two-dimensional MoO_(2)/MoS_(2) step heterostructures with a large specific surface area by the chemical vapor deposition method.Surface Kelvin probe force microscopy and electrical transport measurement verified the asymmetric charge distribution at a single interface.By fabricating a series of micro on-chip electrocatalytic devices,we investigate the HER performance for a single interface and confirm that the interface is essential for superior catalytic performance.We experimentally confirmed that the enhancement of the HER performance of step heterostructure is attributed to the asymmetric charge distribution at the interface.This work lays a foundation for designing highly efficient catalytic systems based on step heterostructures.
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the National Key R&D Program of China(No.2017YFA0204800)the National Natural Science Foundation of China(Nos.22033002,21525311,and 21973011)the Scientific Research Foundation of Graduate School of Southeast University(No.YBPY1968).
文摘Two-dimensional(2D)materials,due to its excellent mechanical,unique electrical and optical properties,have become hot materials in the field of photocatalysis.Especially,2D heterostructures can well inhibit the recombination of photogenerated electrons and holes in photocatalysis because of its special energy band structures and carrier transport characteristics,which are conducive to enhancing photoenergy conversion capacity and improving oxidation and reduction ability,so as to purify pollutants and store energy.In this minireview,we summarize recent theoretical progress in direct Z-scheme photocatalysis of 2D heterostructures,focusing on physical mechanism and improving catalytic efficiency.Current challenges and prospects for 2D direct Z-scheme photocatalysts are discussed as well.
文摘Magnetotransport properties of two-dimensional electron gases （2DEG） in AlxGa1-x N/GaN heterostructures with different Al compositions are investigated by magnetotransport measurements at low temperatures and in high magnetic fields. It is found that heterostructures with a lower Al composition in the barrier have lower 2DEG concentration and higher 2DEG mobility.
文摘Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.
基金financially supported by the National Key Research and Development Program of China(Grant No.2021YFA1400403)the National Natural Science Foundation of China(Grant Nos.12374183,92165205)+2 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the Fundamental Research Funds for the Central Universities(Grant No.020414380207).
文摘Interplay between topology and magnetism can give rise to exotic properties in topological materials.Two-dimensional bismuth has been extensively studied owing to its topological states with a strong spin-orbit coupling,and 1T-VTe_(2)monolayer theoretically predicted to host an intrinsic magnetism as experimentally suggested.In this work,we successfully constructed a vertical heterostructure composed of the two-dimensional Bi(110)monolayer and 1T-VTe_(2)monolayer by using molecular beam epitaxy(MBE).Scanning tunneling microscopy(STM)measurements revealed that the growth of Bi preferably occurs along the step edges of the VTe_(2)monolayer,forming a Bi(110)monolayer on top of the VTe_(2)monolayer next to a peripheral Bi bilayer.The Bi(100)/VTe_(2)heterostructure exhibits a specific lattice registry with a well-defined moiréperiodicity.Scanning tunneling spectroscopy(STS)measurements further unveiled an universal suppression in the local density-of-states at the boundary of the Bi(110)/VTe_(2)bilayer.By examining the atomic structures of Bi(110)boundaries,we found this effect does not originate from the previously proposed atomic reconstruction at the step edge of Bi(110),but is likely related to the magnetic properties of the VTe_(2)monolayer.
基金supported by the National 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 the NSFC(12474071)Natural Science Foundation of Shandong Province(ZR2024YQ051,ZR2025QB50)+6 种基金Guangdong Basic and Applied Basic Research Foundation(2025A1515011191)the Shanghai Sailing Program(23YF1402200,23YF1402400)funded by Basic Research Program of Jiangsu(BK20240424)Open Research Fund of State Key Laboratory of Crystal Materials(KF2406)Taishan Scholar Foundation of Shandong Province(tsqn202408006,tsqn202507058)Young Talent of Lifting engineering for Science and Technology in Shandong,China(SDAST2024QTB002)the Qilu Young Scholar Program of Shandong University。
文摘As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies.
基金supported by the Fundamental Research Funds for the Central Universities(WUT:2024IVA052 and Grant No.104972025KFYjc0089)。
文摘Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.
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 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the National Key R&D Program of China(Nos.2018YFA0306900 and 2018YFA0209500)the National Natural Science Foundation of China(No.21872114)the Fundamental Research Funds for the Central Universities(No.20720210009)。
文摘Hydrogen production by photoelectrochemical(PEC) water splitting converts the inexhaustible supply of solar radiation to storable H2 as clean energy and thus has received widespread attention.The efficiency of PEC water splitting is largely determined by the properties of the photoelectrodes.Two-dimensional(2 D) layered transition metal dichalcogenides(TMDs) are promising candidates for photoelectrodes due to their atomic layer thickness,tunable bandgap,large specific surface area,and high carrier mobility.Moreover,the construction of 2 D TMDs heterostructures provides freedom in material design,which facilitates the further improvement of PEC water splitting.This review begins by describing the mechanism of PEC water splitting and the advantages of 2 D TMDbased heterostructures for photo electrodes.Then,the design considerations of the heterostructures for enhanced PEC efficiency are comprehensively reviewed with a focus on material selection,band engineering,surface modification,and long-term durability.Finally,current challenges and future perspectives for the development of photoelectrodes based on 2 D TMDs heterostructures are addressed.
基金funding from the National Natural Science Foundation of China(No.52002267).
文摘Regarding the reverse process of materials growth,etching has been widely concerned to indirectly probe the growth kinetics,offering an avenue in governing the growth of two-dimensional(2D)materials.In this work,interface-driven anisotropic etching mode is demonstrated for the first time to be generally applied to 2D heterostructures.It is shown that the typical in-plane graphene and hexagonal boron nitride(h-BN)heterostructures follow a multi-stage etching behavior initiated first along the interfacial region between the two materials and then along edges of neighboring h-BN flakes and finally along central edges of hBN.By accurately tuning etching conditions in the chemical vapor deposition process,series of etched 2D heterostructure patterns are controllably produced.Furthermore,scaled formation of graphene and h-BN heterostructures arrays has been realized with full assist of as-proposed etching mechanism,offering a direct top-down method to make 2D orientated heterostructures with order and complexity.Detection of interface-driven multi-staged anisotropic etching mode will shed light on understanding growth mechanism and further expanding wide applications of 2D heterostructures.
