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
Two-dimensional(2D) materials with potential applications in photonic and optoelectronic devices have attracted increasing attention due to their unique structures and captivating properties. However, generation of st...Two-dimensional(2D) materials with potential applications in photonic and optoelectronic devices have attracted increasing attention due to their unique structures and captivating properties. However, generation of stable high-energy ultrashort pulses requires further boosting of these materials' optical properties, such as higher damage threshold and larger modulation depth. Here we investigate a new type of heterostructure material with uniformity by employing the magnetron sputtering technique. Heterostructure materials are synthesized with van der Waals heterostructures consisting of MoS_2 and Sb_2Te_3. The bandgap, carrier mobility, and carrier concentration of the MoS_2-Sb_2Te_3-MoS_2 heterostructure materials are calculated theoretically. By using these materials as saturable absorbers(SAs), applications in fiber lasers with Q-switching and mode-locking states are demonstrated experimentally. The modulation depth and damage threshold of SAs are measured to be 64.17%and 14.13 J∕cm^2, respectively. Both theoretical and experimental results indicate that MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have large modulation depth, and can resist high power during the generation of ultrashort pulses. The MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have the advantages of low cost, high reliability, and suitability for mass production, and provide a promising solution for the development of 2D-material-based devices with desirable electronic and optoelectronic properties.展开更多
Dispersive strain bands have been reported as a characteristic deformation feature of heterostructured materials,which helps to improve ductility.However,their formation mechanism is still not well understood.Here we ...Dispersive strain bands have been reported as a characteristic deformation feature of heterostructured materials,which helps to improve ductility.However,their formation mechanism is still not well understood.Here we report the formation of dispersed strain bands through dual-level hierarchical strain banding and its effect on the mechanical behavior of a heterostructured Fe-40Cu model material.Specifically,deformation started by the formation and propagation of dispersed microscale strain bands in the heterostructured Fe-40Cu material.High strain gradient was generated within the microscale strain bands during their propagation and was accommodated by the accumulation of geometrically necessary disloca-tions(GNDs).The dispersed microscale strain bands were not uniformly distributed,but instead grouped together to form macroscale strain bands that were uniformly distributed over the entire gage section to accommodate the majority of the applied strain.The formation of this dual-level hierarchical strain bands prevented the formation of large strain localization to fail the sample prematurely.It was also found that increasing the strain hardening capacity of soft copper zones provides more room for the accumulation of GNDs,resulting in higher constraint to microscale strain band propagation and consequently higher ductility.These observations suggest the possibility of tailoring microscale strain bands to optimize tensile performance of heterostructured materials.展开更多
Heterostructured materials,characterized by distinct microstructures and mechanical properties across different micro-regions,have consistently demonstrated their ability to effectively mitigate the strength-ductility...Heterostructured materials,characterized by distinct microstructures and mechanical properties across different micro-regions,have consistently demonstrated their ability to effectively mitigate the strength-ductility trade-off in structural materials.Mechanisms such as geometrically necessary dislocations and heterogeneous deformation-induced strengthening have been proposed to elucidate their strengthening and toughening processes.Despite their promising potential in theoretical studies and laboratory settings,industrial applications remain limited due to challenges such as high production costs and inadequate understanding of critical properties including fatigue resistance and corrosion behavior.This review explores manufacturing methods for heterogeneous structures,strategies for microstructure regulation,and future research directions for advancing their industrial applications.展开更多
Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batterie...Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batteries face a series of vital challenges from sulfur cathode and sodium anode:(i)sluggish reaction kinetics of S and Na_(2)S/Na_(2)S_(2);(ii)severe shuttle effect from the dissolved intermediate sodium polysulfides(NaPSs);(iii)huge volume expansion induced by the change from S to Na_(2)S;(iv)continuous growth of sodium metal dendrites,leading to short-circuiting of the battery;(v)huge volume expansion/contraction of sodium anode upon sodium plating/stripping,causing uncontrollable solid-state electrolyte interphase growth and“dead sodium”formation.Various strategies have been proposed to address these issues,including physical/chemical adsorption of NaPSs,catalysts to facilitate the rapid conversion of NaPSs,high-conductive materials to promote ion/electron transfer,good sodiophilic Na anode hetero-interface homogenized Na ions flux and three-dimensional porous anode host to buffer the volume expansion of sodium.Heterostructure materials can combine these merits into one material to realize multifunctionality.Herein,the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed.First of all,the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na-S batteries are described.Then,the application of heterostructures in Na-S batteries is comprehensively examined.Finally,the current primary avenues of employing heterostructures in Na-S batteries are summarized.Opinions and prospects are put forward regarding the existing problems in current research,aiming to inspire the design of advanced and improved next-generation Na-S batteries.展开更多
Ultrafine-grained aluminum alloys are of interest due to their high strength-to-weight ratio,but they usually suffer from poor uniform ductility.In this study,an Al-Au alloy with a good combination of strength and duc...Ultrafine-grained aluminum alloys are of interest due to their high strength-to-weight ratio,but they usually suffer from poor uniform ductility.In this study,an Al-Au alloy with a good combination of strength and ductility is produced by the heterogeneous distribution of Al2 Au nanoparticles in an alu-minum matrix.To generate such heterogeneity,the alloy is synthesized by ultra-severe plastic deforma-tion of aluminum and gold powders via the high-pressure torsion(HPT)method.Reactive interdiffusion occurs during the process leading to the heterogeneous formation of intermetallic particles and a good strength-ductility synergy(200 MPa yield stress and 15%uniform elongation).Nanoparticles gradually distribute within the matrix and once a uniform nanoparticle distribution is achieved,the alloy shows no further increase in strength,but it completely loses its ductility.It is concluded that not only the pres-ence of nanoparticles but more importantly the heterogeneity of their distribution can positively influ-ence the strength-ductility combination in ultrafine-grained aluminum alloys.The findings of this study suggest that future studies on heterogeneous precipitation hardening can be a solution to achieve ductile precipitation-hardened alloys.展开更多
Doping control has been a key challenge for electronic applications of van der Waals materials.Here,we demonstrate complementary doping of black phosphorus using controlled ionic intercalation to achieve monolithic bu...Doping control has been a key challenge for electronic applications of van der Waals materials.Here,we demonstrate complementary doping of black phosphorus using controlled ionic intercalation to achieve monolithic building elements.We characterize the anisotropic electrical transport as a function of ion concentrations and report a widely tunable resistivity up to three orders of magnitude with characteristic concentration dependence corresponding to phase transitions during intercalation.As a further step,we develop both p-type and n-type field effect transistors as well as electrical diodes with high device stability and performance.In addition,enhanced charge mobility from 380 to 820 cm^2/(V·s)with the intercalation process is observed and explained as the suppressed neutral impurity scattering based on our ab initio calculations.Our study provides a unique approach to atomically control the electrical properties of van der Waals materials,and may open up new opportunities in developing advanced electronics and physics platforms.展开更多
Van der Waals heterostructures,composed of individual two-dimensional material have been developing extremely fast.Synthesis of van der Waals heterostructures without the constraint of lattice matching and processing ...Van der Waals heterostructures,composed of individual two-dimensional material have been developing extremely fast.Synthesis of van der Waals heterostructures without the constraint of lattice matching and processing compatibility provides an ideal platform for fundamental research and new device exploitation.We review the approach of synthesis of van der Waals heterostructures,discuss the property of heterostructures and thoroughly illustrate the functional van der Waals heterostructures used in novel electronic and photoelectronic device.展开更多
In-memory computing has carried out calculations in situ within each memory unit and its main power consumption comes from data writ-ing and erasing.Further improvements in the energy efficiency of in-memory computing...In-memory computing has carried out calculations in situ within each memory unit and its main power consumption comes from data writ-ing and erasing.Further improvements in the energy efficiency of in-memory computing require memory devices with sub-femto-Joule energy consumption.Floating gate memory devices based on two-dimensional(2D)material heterostructures have outstanding char-acteristics such as non-volatility,multi-bit storage,and low opera-tion energy,suitable for application in in-memory computing chips.Here,we report a floating gate memory device based on a WSe 2/h-BN/Multilayer-graphene/h-BN heterostructure,the energy consump-tion of which is in sub-femto Joule(0.6 fJ)per operation for pro-gram/erase,and the read power consumption is in the tens of femto Watt(60 fW)range.We show a Hopfield neural network composed of WSe 2/h-BN/Multilayer-graphene/h-BN heterostructure floating gate memory devices,which can recall the original patterns from incorrect patterns.These results shed light on the development of future com-pact and energy-efficient hardware for in-memory computing sys-tems.展开更多
The electrochemical reduction of NO_(3)^(−)to NH_(3)represents a promising approach for producing a renewable fuel with high energy density.However,problems such as low activity and/or selectivity in low-concentration...The electrochemical reduction of NO_(3)^(−)to NH_(3)represents a promising approach for producing a renewable fuel with high energy density.However,problems such as low activity and/or selectivity in low-concentration solutions(≤100 ppm NO_(3)^(−)-N)and instability of active sites still require to be overcome.In this work,Cu/ZnO heterostructure composite materials were synthesized for the NO_(3)RR.During the electrocatalysis process,Cu/ZnO undergoes electrochemistry-driven structural reconstruction,generating the CuZn bimetallic alloy phase.In a dilute NO_(3)^(−)-N solution of 100 ppm,the optimal Cu_(75)Zn_(25)catalyst exhibits an FENH_(3)of 94.1%at−0.7 V vs.RHE,and a high NH_(3)yield of 414 mmol h^(−1)g_(cat)^(−1).Density functional theory calculations and a series of characterization studies unveiled that the CuZn alloy phase alters the electronic state surrounding Cu,leading to the regulation of the Cu d-band center and thereby optimizing the adsorption of intermediates.Meanwhile,forming a new alloy phase inhibits the competitive HER as well.This study shows the prospect of the CuZn composite catalyst in sustainable NH_(3)synthesis,which holds a certain guiding significance for the efficient and eco-friendly conversion of effluents in the future.展开更多
Layered Li-rich oxides have attracted much attention because of higher capacity than that of traditional layered oxides(more than 250 mAh g^(−1)).However,the intrinsic issues of Li-rich cathode materials suffer from l...Layered Li-rich oxides have attracted much attention because of higher capacity than that of traditional layered oxides(more than 250 mAh g^(−1)).However,the intrinsic issues of Li-rich cathode materials suffer from lattice oxygen loss,poor rate capability,voltage fade,and limited cycle life.To tackle these problems,the Li-rich cathode containing intergrown layer and spinel phases was proposed,and this heterostructure material meets the requirements of high energy and stable surface with a fast Li^(+)diffusion channel.Herein,we review the recent progress and in-depth understanding about heterostructure including microstructure and morphology,performance of advancement and degradation mechanisms,and modification strategies.Special attention is given to the high-performance energy mechanism as follows:(a)spinel phase and oxygen vacancy jointly enhance the lattice structure and prevent the irreversible oxygen release,(b)higher capacity is achieved by promotion of activation of Li_(2)MnO_(3) phase and control of the activation rate to realize stable long-term cyclability,and(c)spinel phase provides the 3D interconnected Li^(+)diffusion channels and protects the surface region from side reactions.The other issue that aroused interest is the undesirable changes of phase transition and degradation mechanisms as follows:(a)the key reconstruction process is to produce a“good”spinel to maintain the surface and interior structure stability.(b)It is significant to figure out the structure degradation and phase transition mechanism in the cycled heterostructure.This review aims to provide inspiration and opportunities for the design of high-energy-density cathode materials,thereby bridging the gap between laboratory research and practical battery applications.展开更多
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].
基金National Natural Science Foundation of China(NSFC)(11674036)Beijing University of Posts and Telecommunications(BUPT)(IPOC2016ZT04,IPOC2017ZZ05)+2 种基金Beijing Youth Top-Notch Talent Support Program(2017000026833ZK08)Special Program for Applied Research on Super Computation of the NSFC Guangdong Joint Fund(U1501501)XAFS Station(BL14W1)
文摘Two-dimensional(2D) materials with potential applications in photonic and optoelectronic devices have attracted increasing attention due to their unique structures and captivating properties. However, generation of stable high-energy ultrashort pulses requires further boosting of these materials' optical properties, such as higher damage threshold and larger modulation depth. Here we investigate a new type of heterostructure material with uniformity by employing the magnetron sputtering technique. Heterostructure materials are synthesized with van der Waals heterostructures consisting of MoS_2 and Sb_2Te_3. The bandgap, carrier mobility, and carrier concentration of the MoS_2-Sb_2Te_3-MoS_2 heterostructure materials are calculated theoretically. By using these materials as saturable absorbers(SAs), applications in fiber lasers with Q-switching and mode-locking states are demonstrated experimentally. The modulation depth and damage threshold of SAs are measured to be 64.17%and 14.13 J∕cm^2, respectively. Both theoretical and experimental results indicate that MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have large modulation depth, and can resist high power during the generation of ultrashort pulses. The MoS_2-Sb_2Te_3-MoS_2 heterostructure materials have the advantages of low cost, high reliability, and suitability for mass production, and provide a promising solution for the development of 2D-material-based devices with desirable electronic and optoelectronic properties.
基金Y.T.Zhu acknowledges the support of the National Key R&D Program of China(Grant No.2021YFA1200202)the National Natural Science Foundation of China(Grant No.51931003)the Hong Kong Research Grants Council(Grant No.GRF 11214121)。
文摘Dispersive strain bands have been reported as a characteristic deformation feature of heterostructured materials,which helps to improve ductility.However,their formation mechanism is still not well understood.Here we report the formation of dispersed strain bands through dual-level hierarchical strain banding and its effect on the mechanical behavior of a heterostructured Fe-40Cu model material.Specifically,deformation started by the formation and propagation of dispersed microscale strain bands in the heterostructured Fe-40Cu material.High strain gradient was generated within the microscale strain bands during their propagation and was accommodated by the accumulation of geometrically necessary disloca-tions(GNDs).The dispersed microscale strain bands were not uniformly distributed,but instead grouped together to form macroscale strain bands that were uniformly distributed over the entire gage section to accommodate the majority of the applied strain.The formation of this dual-level hierarchical strain bands prevented the formation of large strain localization to fail the sample prematurely.It was also found that increasing the strain hardening capacity of soft copper zones provides more room for the accumulation of GNDs,resulting in higher constraint to microscale strain band propagation and consequently higher ductility.These observations suggest the possibility of tailoring microscale strain bands to optimize tensile performance of heterostructured materials.
基金support by the Guangxi Key Laboratory of Information Materials(231031-K),Guangdong Basic and Applied Basic Research Foundation(2024A1515011943)the National Natural Science Foundation of China(52401170)+9 种基金Research Grants Council-Early Career Scheme(26220124)General Research Fund(16221625)Young Collaborative Research Grant(C5002-24Y),KTH GKNA 2024(006)National Natural Science Foundation of China(52561026)Guangxi Natural Science Foundation(2025GXNSFAA069636)Specific Research Project of Guangxi for Research Bases and Talents(AD22035997)Guangxi Key Laboratory of Information Materials(Guangxi Science and Technology 231058-Z)Specific Research Project of Guangxi for Research Bases and Talents(AD22035997)Guangdong Basic and Applied Basic Research Foundation(2025A1515012085)National Natural Science Foundation of China(51901251).
文摘Heterostructured materials,characterized by distinct microstructures and mechanical properties across different micro-regions,have consistently demonstrated their ability to effectively mitigate the strength-ductility trade-off in structural materials.Mechanisms such as geometrically necessary dislocations and heterogeneous deformation-induced strengthening have been proposed to elucidate their strengthening and toughening processes.Despite their promising potential in theoretical studies and laboratory settings,industrial applications remain limited due to challenges such as high production costs and inadequate understanding of critical properties including fatigue resistance and corrosion behavior.This review explores manufacturing methods for heterogeneous structures,strategies for microstructure regulation,and future research directions for advancing their industrial applications.
基金MOE SUTD Kickstarter initiative,Grant/Award Number:SKI2021_02_16111 Project,Grant/Award Number:D20015National Natural Science Foundation of China,Grant/Award Number:22109183。
文摘Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batteries face a series of vital challenges from sulfur cathode and sodium anode:(i)sluggish reaction kinetics of S and Na_(2)S/Na_(2)S_(2);(ii)severe shuttle effect from the dissolved intermediate sodium polysulfides(NaPSs);(iii)huge volume expansion induced by the change from S to Na_(2)S;(iv)continuous growth of sodium metal dendrites,leading to short-circuiting of the battery;(v)huge volume expansion/contraction of sodium anode upon sodium plating/stripping,causing uncontrollable solid-state electrolyte interphase growth and“dead sodium”formation.Various strategies have been proposed to address these issues,including physical/chemical adsorption of NaPSs,catalysts to facilitate the rapid conversion of NaPSs,high-conductive materials to promote ion/electron transfer,good sodiophilic Na anode hetero-interface homogenized Na ions flux and three-dimensional porous anode host to buffer the volume expansion of sodium.Heterostructure materials can combine these merits into one material to realize multifunctionality.Herein,the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed.First of all,the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na-S batteries are described.Then,the application of heterostructures in Na-S batteries is comprehensively examined.Finally,the current primary avenues of employing heterostructures in Na-S batteries are summarized.Opinions and prospects are put forward regarding the existing problems in current research,aiming to inspire the design of advanced and improved next-generation Na-S batteries.
文摘Ultrafine-grained aluminum alloys are of interest due to their high strength-to-weight ratio,but they usually suffer from poor uniform ductility.In this study,an Al-Au alloy with a good combination of strength and ductility is produced by the heterogeneous distribution of Al2 Au nanoparticles in an alu-minum matrix.To generate such heterogeneity,the alloy is synthesized by ultra-severe plastic deforma-tion of aluminum and gold powders via the high-pressure torsion(HPT)method.Reactive interdiffusion occurs during the process leading to the heterogeneous formation of intermetallic particles and a good strength-ductility synergy(200 MPa yield stress and 15%uniform elongation).Nanoparticles gradually distribute within the matrix and once a uniform nanoparticle distribution is achieved,the alloy shows no further increase in strength,but it completely loses its ductility.It is concluded that not only the pres-ence of nanoparticles but more importantly the heterogeneity of their distribution can positively influ-ence the strength-ductility combination in ultrafine-grained aluminum alloys.The findings of this study suggest that future studies on heterogeneous precipitation hardening can be a solution to achieve ductile precipitation-hardened alloys.
基金Y.H.acknowledges support from a CAREER award from the National Science Foundation under grant DMR-1753393,an Alfred P Sloan Research Fellowship under grant FG-2019-1178&a Young Investigator Award from the US Air Force Office of Scientific Research under grant FA9550-17-1-0149,a Doctoral New Investigator Award from the American Chemical Society Petroleum Research Fund under grant 58206-DNI5,as well as from the UCLA Sustainable LA Grand Challenge and the Anthony and Jeanne Pritzker Family Foundation.This work used the Extreme Science and Engineering Discovery Environment(XSEDE),which is supported by National Science Foundation grant number ACI-1548562.Specifically,it used the Bridges system,which is supported by NSF award number ACI-1445606,at the Pittsburgh Supercomputing Center(PSC).
文摘Doping control has been a key challenge for electronic applications of van der Waals materials.Here,we demonstrate complementary doping of black phosphorus using controlled ionic intercalation to achieve monolithic building elements.We characterize the anisotropic electrical transport as a function of ion concentrations and report a widely tunable resistivity up to three orders of magnitude with characteristic concentration dependence corresponding to phase transitions during intercalation.As a further step,we develop both p-type and n-type field effect transistors as well as electrical diodes with high device stability and performance.In addition,enhanced charge mobility from 380 to 820 cm^2/(V·s)with the intercalation process is observed and explained as the suppressed neutral impurity scattering based on our ab initio calculations.Our study provides a unique approach to atomically control the electrical properties of van der Waals materials,and may open up new opportunities in developing advanced electronics and physics platforms.
基金Project supported by the National Key Research and Development Program(No.2016YFA0203900)the National Natural Science Foundation of China(Nos.61376093,61622401)
文摘Van der Waals heterostructures,composed of individual two-dimensional material have been developing extremely fast.Synthesis of van der Waals heterostructures without the constraint of lattice matching and processing compatibility provides an ideal platform for fundamental research and new device exploitation.We review the approach of synthesis of van der Waals heterostructures,discuss the property of heterostructures and thoroughly illustrate the functional van der Waals heterostructures used in novel electronic and photoelectronic device.
基金This work was supported in part by the National Key Research and Development Program of China under Grant 2020YFB2008802 and Grant 2020YFB2008803in part by the Fundamental Research Funds for the Cen-tral Universities under Grant WK2100230020in part by the USTC Center for Micro and Nanoscale Research and Fabrication,in part by the USTC In-stitute of Advanced Technology,and in part by the CAS Key Laboratory of Wireless-Optical Communications.
文摘In-memory computing has carried out calculations in situ within each memory unit and its main power consumption comes from data writ-ing and erasing.Further improvements in the energy efficiency of in-memory computing require memory devices with sub-femto-Joule energy consumption.Floating gate memory devices based on two-dimensional(2D)material heterostructures have outstanding char-acteristics such as non-volatility,multi-bit storage,and low opera-tion energy,suitable for application in in-memory computing chips.Here,we report a floating gate memory device based on a WSe 2/h-BN/Multilayer-graphene/h-BN heterostructure,the energy consump-tion of which is in sub-femto Joule(0.6 fJ)per operation for pro-gram/erase,and the read power consumption is in the tens of femto Watt(60 fW)range.We show a Hopfield neural network composed of WSe 2/h-BN/Multilayer-graphene/h-BN heterostructure floating gate memory devices,which can recall the original patterns from incorrect patterns.These results shed light on the development of future com-pact and energy-efficient hardware for in-memory computing sys-tems.
基金supported by the National Natural Science Foundation of China(No.22278108 and 22008048)the Natural Science Foundation of Tianjin(22JCYBJC00250 and 23JCQNJC00360)+2 种基金the Natural Science Foundation for Outstanding Youth Scholars of Hebei Province(No.B2024202008)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(KF2314)the Government Guide the Development of Local Science and Technology Special Funds(246Z4004G).
文摘The electrochemical reduction of NO_(3)^(−)to NH_(3)represents a promising approach for producing a renewable fuel with high energy density.However,problems such as low activity and/or selectivity in low-concentration solutions(≤100 ppm NO_(3)^(−)-N)and instability of active sites still require to be overcome.In this work,Cu/ZnO heterostructure composite materials were synthesized for the NO_(3)RR.During the electrocatalysis process,Cu/ZnO undergoes electrochemistry-driven structural reconstruction,generating the CuZn bimetallic alloy phase.In a dilute NO_(3)^(−)-N solution of 100 ppm,the optimal Cu_(75)Zn_(25)catalyst exhibits an FENH_(3)of 94.1%at−0.7 V vs.RHE,and a high NH_(3)yield of 414 mmol h^(−1)g_(cat)^(−1).Density functional theory calculations and a series of characterization studies unveiled that the CuZn alloy phase alters the electronic state surrounding Cu,leading to the regulation of the Cu d-band center and thereby optimizing the adsorption of intermediates.Meanwhile,forming a new alloy phase inhibits the competitive HER as well.This study shows the prospect of the CuZn composite catalyst in sustainable NH_(3)synthesis,which holds a certain guiding significance for the efficient and eco-friendly conversion of effluents in the future.
基金supported by the National Natural Science Foundation of China(22179008 and 21875022)the Yibin“Jie Bang Gua Shuai”(2022JB004)+1 种基金support from the Postdoctoral Fellowship Program of CPSF(GZB20230931)the Special Support of Chongqing Postdoctoral Research Project(2023CQBSHTB2041).
文摘Layered Li-rich oxides have attracted much attention because of higher capacity than that of traditional layered oxides(more than 250 mAh g^(−1)).However,the intrinsic issues of Li-rich cathode materials suffer from lattice oxygen loss,poor rate capability,voltage fade,and limited cycle life.To tackle these problems,the Li-rich cathode containing intergrown layer and spinel phases was proposed,and this heterostructure material meets the requirements of high energy and stable surface with a fast Li^(+)diffusion channel.Herein,we review the recent progress and in-depth understanding about heterostructure including microstructure and morphology,performance of advancement and degradation mechanisms,and modification strategies.Special attention is given to the high-performance energy mechanism as follows:(a)spinel phase and oxygen vacancy jointly enhance the lattice structure and prevent the irreversible oxygen release,(b)higher capacity is achieved by promotion of activation of Li_(2)MnO_(3) phase and control of the activation rate to realize stable long-term cyclability,and(c)spinel phase provides the 3D interconnected Li^(+)diffusion channels and protects the surface region from side reactions.The other issue that aroused interest is the undesirable changes of phase transition and degradation mechanisms as follows:(a)the key reconstruction process is to produce a“good”spinel to maintain the surface and interior structure stability.(b)It is significant to figure out the structure degradation and phase transition mechanism in the cycled heterostructure.This review aims to provide inspiration and opportunities for the design of high-energy-density cathode materials,thereby bridging the gap between laboratory research and practical battery applications.
