Biomolecular self-assembly has lately emerged as an intriguing method for creating stable gas-liquid dis-persions with unique functional characteristics.In this work,protein-metal coordination complexes were designed ...Biomolecular self-assembly has lately emerged as an intriguing method for creating stable gas-liquid dis-persions with unique functional characteristics.In this work,protein-metal coordination complexes were designed as the stabilizer for generating ultrastable fire-fighting foam and creating interfacial architec-tures that were actively switched between"rigid"and"mobile"interfacial states of liquid films in re-sponse to changes in pH and bulk solution compositions(metal ions or alkyl polyglycosides).The re-flected light interferometric technique was used to check interfacial states,and the foaming kinetics and rheological response of aqueous solution and liquid foam were investigated by dynamic surface tension tests and oscillatory rheology analysis.The results showed that liquid foams with mobile films with lower yield limits had a faster spreading rate to cover the burning oil,liquid foams with semi-rigid films can-not extinguish fires due to interfacial instability,and the enhanced rheology of the foam with rigid films established a robust and impenetrable barrier to effectively suppress fuel evaporation and combustion.A new correlation between interfacial properties and the fire-fighting performance of foam was proposed,which showed that the fire-extinguishing time of foam could be well correlated by the interfacial states or film lifetime rather than classical thermodynamics entry,spreading,and bridging coefficients(ESB co-efficients).展开更多
We present an ultrasensitive ultraviolet （UV） detector based on a p-type ZnS nanoribbon （NR）/indium tin oxide （ITO） Schottky barrier diode （SBD）. The device exhibits a pseudo-photovoltaic behavior which can al...We present an ultrasensitive ultraviolet （UV） detector based on a p-type ZnS nanoribbon （NR）/indium tin oxide （ITO） Schottky barrier diode （SBD）. The device exhibits a pseudo-photovoltaic behavior which can allow the SBD to detect UV light irradiation with incident power of 6 × 10^-17 W （-85 photons/s on the NR） at room temperature, with excellent reproducibility and stability. The corresponding detectivity and photoconductive gain are calculated to be 3.1 × 10^20 cm.Hz1/2.W^-1 and 6.6 × 10^5, respectively. It is found that the presence of the trapping states at the p-ZnS NWITO interface plays a crucial role in determining the ultrahigh sensitivity of this nanoSBDs. Based on our theoretical calculation, even ultra-low photon fluxes on the order of several tens of photons could induce a significant change in interface potential and consequently cause a large photocurrent variation. The present study provides new opportunities for developiphigh-performance optoelectronic devices in the future.展开更多
Constructing the hetrostructure is a feasible strategy to enhance the performances of photocatalysts. However, there are still some fundamental details and mechanisms for the specific design of photocatalysts with het...Constructing the hetrostructure is a feasible strategy to enhance the performances of photocatalysts. However, there are still some fundamental details and mechanisms for the specific design of photocatalysts with heterostructure,which need further confirming and explain.In this work,g-C_(3)N_(4)-based heterostructures are constructed with TiO_(2) in different ways,and their intrinsic factors to improve the photocatalytic activity are systematically studied by density functional theory(DFT).When g-C_(3)N_(4) combines horizontally with TiO_(2) to form a heterostructure,the interaction between them is dominated by van der Waals interaction.Although the recombination of photo-generated electron-hole pair cannot be inhibited significantly,this van der Waals interaction can regulate the electronic structures of the two components,which is conducive to the participation of photo-generated electrons and holes in the photocatalytic reaction.When the g-C_(3)N_(4) combines vertically with TiO_(2) to form a heterostructure,their interface states show obvious covalent features,which is very beneficial for the photo-generated electrons’ and holes’ transport along the opposite directions on both sides of the interface.Furthermore,the built-in electric field of g-C_(3)N_(4)/TiO_(2) heterostructure is directed from TiO_(2) layer to g-C_(3)N_(4) layer under equilibrium,so the photo-generated electron-hole pairs can be spatially separated from each other.These calculated results show that no matter how g-C_(3)N_(4) and TiO_(2) are combined together,the g-C_(3)N_(4)/TiO_(2) heterostructure can enhance the photocatalytic performance through corresponding ways.展开更多
The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine s...The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine structure of both the materials inter- faces and interfacial reaction products in semiconductor uperlattice,metal multilayer ceram- ics and composite materials by mean of selected area electron doffraction patterns and high resolution electron microscopy. The following features of interfaces are reviewed:the orientation relationships;the char- acteristic of steps,facets and ronghness of interfaces;atomic bonding across the interface;the degree of coherency,the structure of misfit dislocations and elastic relaxations at the inter- faces:the presence of defects at the onterfaces:the structure of the interfacial reaction prod- ucts as well as the reaction kinetics and reaetion mechanism.展开更多
Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf（Zr）O2, in order to minimize current...Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf（Zr）O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant （high-κ） dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping.Ⅲ-Ⅴ and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf（Zr）O2/Ⅲ-Ⅴ（Ge） has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf（Zr）O2/Ⅲ-Ⅴ（Ge） interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first- principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As--As dimer bonding, Ga partial oxidation （between 3＋ and 1＋） and Ga- dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.展开更多
Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the p...Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the possible maximum apparent current density that a given ASSLSC system can endure and how to reveal this potential still require study.Herein,a capacity perturbation strategy aiming to better measure the possible maximum j_(Ac)^(a)is proposed for the first time.With garnet-based plane-surface structure ASSLSCs as an exemplification,the j_(Ac)^(a)is quite small when the capacity is dramatically large.Under a perturbed capacity of 0.001 mA h cm^(-2),the j_(Ac)^(a)is determined to be as high as 2.35 mA cm^(-2)at room temperature.This investigation demonstrates that the capacity perturbation strategy is a feasible strategy for measuring the possible maximum j_(Ac)^(a)of Li/solid electrolyte interface,and hopefully provides good references to explore the critical current density of other types of electrochemical systems.展开更多
Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the int...Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the interfacial localized states with potential fluctuations at the GaN/AlGaN heterointerface leads to photoluminescence peaks showing blue and S-shaped shifts owing to the excitation power and temperature,respectively.Photoexcited electrons in the localized states show a spin relaxation time longer than 1 ns because of the suppression of the D’yakonov-Perel’(DP)scattering,while the spin relaxation time of free electrons was approximately only 10 ps because of the giant Rashba spin-orbit coupling induced by the interfacial polarization field under the framework of the DP scattering mechanism.Furthermore,it is found that the high electron mobility at the heterointerface results in a long spin diffusion length of 300 nm at high temperatures,which is promising for the development of GaN-based spintronic devices.展开更多
The admittance measurements of a hetero-junction can be used to derive the density of the interfacial state in the hetero-junction. Hence, prediction conductance via frequency is very useful for comprehension of the a...The admittance measurements of a hetero-junction can be used to derive the density of the interfacial state in the hetero-junction. Hence, prediction conductance via frequency is very useful for comprehension of the admittance of a hetero-junction using a mathematical strategy. From the observations on the curve of the frequencydependent conductance of the hetero-junction an analytic model with four-parameters was developed that relates conductance to frequency; the theoretical results agree quite well with the experimental data. The model shows potential for a variety of applications including different electronic devices. The model is a practical tool that can be readily used for assessing the electronic behaviors of a hetero-junction and is scientifically justifiable. In addition, the mathematical bridge to link the density of the interfacial state of the（pyronine-B）/p-Si structure to energy implies a good route to discuses the density of the interfacial state of interfaces.展开更多
Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this stud...Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this study,we report the thermo‐responsive fluorine‐free foam stabilized by triblock PEO–PPO–PEO copolymers(EO)_(100)(PO)_(65)(EO)_(100)for pool fire suppression.Small‐angle X‐ray scattering(SAXS)and reflected light interferometric techniques are conducted to study the molecular self‐assembly in bulk and film thinning behavior,and the foaming kinetics of copolymer solution and thermophysical properties of the liquid foam are studied by dynamic surface tension and oscillatory rheology analysis.At room temperature,the amphipathic structure of PEO–PPO–PEO makes it possible to absorb at the air–liquid interface forming large‐scale liquid foams containing the mobile films with a detergent state.Upon heating to the surface cooling temperature of burning oil,the mobile films can be actively switched into mechanically strong films with rigid surfaces.The in situ switching of the two interfacial states leads to the significant enhancement of the foam stability,especially under the dual defoaming effects of heat and oil.What's more,it is observed that the confinement of organized copolymer micelles in the Plateau borders and micellar self‐layering in film confinement induce drainage delay of foam and film's stepwise thinning phenomenon,further increasing film thickness and enhancing the thermal stability of the foam.In standard fire‐fighting tests,it is proved that the burnback performance exhibited by thermo‐responsive copolymer foams is three times better than that for classical fluorine‐free foams and almost 1.5 times higher than that for commercial AFFF.展开更多
Liquid foams with tunable and photoresponsive stabilities and mechanical properties are highly desired in many domains,including the chemical and environmental protection industries.Here,we constructed photoresponsive...Liquid foams with tunable and photoresponsive stabilities and mechanical properties are highly desired in many domains,including the chemical and environmental protection industries.Here,we constructed photoresponsive liquid foams by structuring the interfacial adsorption layers and nanoparticle-embedded Plateau borders of the foam with biodegradable components.These foams exhibited ultrahigh foam stability but were easily destroyed by light,leading to a clean recovery of the liquid phase.In the absence of light,the hydroxypropyl cellulose(HPC)coils in the foam formed mechanically strong liquid films or“cohesive states.”Under irradiation,the ultrathin black phosphorus nanosheets induced changes in the packing parameters of the HPC assemblies within the Plateau borders and led to coil-to-globule transitions of the HPC and formed unstable liquid films with a“mobile state.”The two interfacial states were reversibly and repeatedly switched by turning the light on and off,which caused rapid bubble coalescence and foam collapse,and we also proved that this destabilizing mechanism was inhibited by cellulose nanocrystals.This work provides an environmentally friendly approach to controlling foam stability,and the proposed strategy can be expanded to the production of multiresponsive fully liquid objects in theory.展开更多
基金Anhui provincial major science and technology project(No.202103c08020005).
文摘Biomolecular self-assembly has lately emerged as an intriguing method for creating stable gas-liquid dis-persions with unique functional characteristics.In this work,protein-metal coordination complexes were designed as the stabilizer for generating ultrastable fire-fighting foam and creating interfacial architec-tures that were actively switched between"rigid"and"mobile"interfacial states of liquid films in re-sponse to changes in pH and bulk solution compositions(metal ions or alkyl polyglycosides).The re-flected light interferometric technique was used to check interfacial states,and the foaming kinetics and rheological response of aqueous solution and liquid foam were investigated by dynamic surface tension tests and oscillatory rheology analysis.The results showed that liquid foams with mobile films with lower yield limits had a faster spreading rate to cover the burning oil,liquid foams with semi-rigid films can-not extinguish fires due to interfacial instability,and the enhanced rheology of the foam with rigid films established a robust and impenetrable barrier to effectively suppress fuel evaporation and combustion.A new correlation between interfacial properties and the fire-fighting performance of foam was proposed,which showed that the fire-extinguishing time of foam could be well correlated by the interfacial states or film lifetime rather than classical thermodynamics entry,spreading,and bridging coefficients(ESB co-efficients).
文摘We present an ultrasensitive ultraviolet （UV） detector based on a p-type ZnS nanoribbon （NR）/indium tin oxide （ITO） Schottky barrier diode （SBD）. The device exhibits a pseudo-photovoltaic behavior which can allow the SBD to detect UV light irradiation with incident power of 6 × 10^-17 W （-85 photons/s on the NR） at room temperature, with excellent reproducibility and stability. The corresponding detectivity and photoconductive gain are calculated to be 3.1 × 10^20 cm.Hz1/2.W^-1 and 6.6 × 10^5, respectively. It is found that the presence of the trapping states at the p-ZnS NWITO interface plays a crucial role in determining the ultrahigh sensitivity of this nanoSBDs. Based on our theoretical calculation, even ultra-low photon fluxes on the order of several tens of photons could induce a significant change in interface potential and consequently cause a large photocurrent variation. The present study provides new opportunities for developiphigh-performance optoelectronic devices in the future.
基金Project supported by the National Natural Science Foundation of China(Grant No.11964015)。
文摘Constructing the hetrostructure is a feasible strategy to enhance the performances of photocatalysts. However, there are still some fundamental details and mechanisms for the specific design of photocatalysts with heterostructure,which need further confirming and explain.In this work,g-C_(3)N_(4)-based heterostructures are constructed with TiO_(2) in different ways,and their intrinsic factors to improve the photocatalytic activity are systematically studied by density functional theory(DFT).When g-C_(3)N_(4) combines horizontally with TiO_(2) to form a heterostructure,the interaction between them is dominated by van der Waals interaction.Although the recombination of photo-generated electron-hole pair cannot be inhibited significantly,this van der Waals interaction can regulate the electronic structures of the two components,which is conducive to the participation of photo-generated electrons and holes in the photocatalytic reaction.When the g-C_(3)N_(4) combines vertically with TiO_(2) to form a heterostructure,their interface states show obvious covalent features,which is very beneficial for the photo-generated electrons’ and holes’ transport along the opposite directions on both sides of the interface.Furthermore,the built-in electric field of g-C_(3)N_(4)/TiO_(2) heterostructure is directed from TiO_(2) layer to g-C_(3)N_(4) layer under equilibrium,so the photo-generated electron-hole pairs can be spatially separated from each other.These calculated results show that no matter how g-C_(3)N_(4) and TiO_(2) are combined together,the g-C_(3)N_(4)/TiO_(2) heterostructure can enhance the photocatalytic performance through corresponding ways.
文摘The characteristic of interface depending on the atomic structure exerts an inportant,and sometime controlling,influence on performance of the interacial materials. The present paper reviews the main studies on fine structure of both the materials inter- faces and interfacial reaction products in semiconductor uperlattice,metal multilayer ceram- ics and composite materials by mean of selected area electron doffraction patterns and high resolution electron microscopy. The following features of interfaces are reviewed:the orientation relationships;the char- acteristic of steps,facets and ronghness of interfaces;atomic bonding across the interface;the degree of coherency,the structure of misfit dislocations and elastic relaxations at the inter- faces:the presence of defects at the onterfaces:the structure of the interfacial reaction prod- ucts as well as the reaction kinetics and reaetion mechanism.
基金supported by the National Natural Science Foundation of China (11304161, 11104148, and 51171082)the Tianjin Natural Science Foundation (13JCYBJC41100 and 14JCZDJC37700)+3 种基金the National Basic Research Program of China (973 Program) (2014CB931703)Specialized Research Fund for the Doctoral Program of Higher Education (20110031110034)the Fundamental Research Funds for the Central Universitiessupported by the Global Frontier Center for Multiscale Energy Systems at Seoul National University in Korea
文摘Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf（Zr）O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant （high-κ） dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping.Ⅲ-Ⅴ and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf（Zr）O2/Ⅲ-Ⅴ（Ge） has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf（Zr）O2/Ⅲ-Ⅴ（Ge） interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first- principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As--As dimer bonding, Ga partial oxidation （between 3＋ and 1＋） and Ga- dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.
基金the financial support from the Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2020JJ2047)the science and technology innovation Program of Hunan Province(2022RC3048)+2 种基金the Program of Huxiang Young Talents(2019RS2002)the Innovation-Driven Project of Central South University(2020CX027)the Fundamental Research Funds for the Central Universities of Central South University(2021zzts0125)。
文摘Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the possible maximum apparent current density that a given ASSLSC system can endure and how to reveal this potential still require study.Herein,a capacity perturbation strategy aiming to better measure the possible maximum j_(Ac)^(a)is proposed for the first time.With garnet-based plane-surface structure ASSLSCs as an exemplification,the j_(Ac)^(a)is quite small when the capacity is dramatically large.Under a perturbed capacity of 0.001 mA h cm^(-2),the j_(Ac)^(a)is determined to be as high as 2.35 mA cm^(-2)at room temperature.This investigation demonstrates that the capacity perturbation strategy is a feasible strategy for measuring the possible maximum j_(Ac)^(a)of Li/solid electrolyte interface,and hopefully provides good references to explore the critical current density of other types of electrochemical systems.
基金supported by the National Key Research and Development Program of China(Grants No.2018YFB0406603 and 2018YFE0125700)the National Natural Science Foundation of China(Grants No.61574006,61522401,61927806,61521004,and 11634002).
文摘Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the interfacial localized states with potential fluctuations at the GaN/AlGaN heterointerface leads to photoluminescence peaks showing blue and S-shaped shifts owing to the excitation power and temperature,respectively.Photoexcited electrons in the localized states show a spin relaxation time longer than 1 ns because of the suppression of the D’yakonov-Perel’(DP)scattering,while the spin relaxation time of free electrons was approximately only 10 ps because of the giant Rashba spin-orbit coupling induced by the interfacial polarization field under the framework of the DP scattering mechanism.Furthermore,it is found that the high electron mobility at the heterointerface results in a long spin diffusion length of 300 nm at high temperatures,which is promising for the development of GaN-based spintronic devices.
文摘The admittance measurements of a hetero-junction can be used to derive the density of the interfacial state in the hetero-junction. Hence, prediction conductance via frequency is very useful for comprehension of the admittance of a hetero-junction using a mathematical strategy. From the observations on the curve of the frequencydependent conductance of the hetero-junction an analytic model with four-parameters was developed that relates conductance to frequency; the theoretical results agree quite well with the experimental data. The model shows potential for a variety of applications including different electronic devices. The model is a practical tool that can be readily used for assessing the electronic behaviors of a hetero-junction and is scientifically justifiable. In addition, the mathematical bridge to link the density of the interfacial state of the（pyronine-B）/p-Si structure to energy implies a good route to discuses the density of the interfacial state of interfaces.
基金supported by the Basic Research Program of Jiangsu Province(No.BE2020663)the Opening Fund of the State Key Laboratory of Fire Science of the University of Science and Technology of China(No.HZ2022‐KF‐09).
文摘Research and development of novel fluorine‐free materials to replace fluorinated aqueous film‐forming foam(AFFF)are crucial for improving pool fire suppression performance and protecting the environment.In this study,we report the thermo‐responsive fluorine‐free foam stabilized by triblock PEO–PPO–PEO copolymers(EO)_(100)(PO)_(65)(EO)_(100)for pool fire suppression.Small‐angle X‐ray scattering(SAXS)and reflected light interferometric techniques are conducted to study the molecular self‐assembly in bulk and film thinning behavior,and the foaming kinetics of copolymer solution and thermophysical properties of the liquid foam are studied by dynamic surface tension and oscillatory rheology analysis.At room temperature,the amphipathic structure of PEO–PPO–PEO makes it possible to absorb at the air–liquid interface forming large‐scale liquid foams containing the mobile films with a detergent state.Upon heating to the surface cooling temperature of burning oil,the mobile films can be actively switched into mechanically strong films with rigid surfaces.The in situ switching of the two interfacial states leads to the significant enhancement of the foam stability,especially under the dual defoaming effects of heat and oil.What's more,it is observed that the confinement of organized copolymer micelles in the Plateau borders and micellar self‐layering in film confinement induce drainage delay of foam and film's stepwise thinning phenomenon,further increasing film thickness and enhancing the thermal stability of the foam.In standard fire‐fighting tests,it is proved that the burnback performance exhibited by thermo‐responsive copolymer foams is three times better than that for classical fluorine‐free foams and almost 1.5 times higher than that for commercial AFFF.
基金Anhui provincial major science and technology project,Grant/Award Number:202103c08020005National funded postdoctoral researcher program of China,Grant/Award Number:GZB20230714China postdoctoral science foundation funded project,Grant/Award Number:2023M743387。
文摘Liquid foams with tunable and photoresponsive stabilities and mechanical properties are highly desired in many domains,including the chemical and environmental protection industries.Here,we constructed photoresponsive liquid foams by structuring the interfacial adsorption layers and nanoparticle-embedded Plateau borders of the foam with biodegradable components.These foams exhibited ultrahigh foam stability but were easily destroyed by light,leading to a clean recovery of the liquid phase.In the absence of light,the hydroxypropyl cellulose(HPC)coils in the foam formed mechanically strong liquid films or“cohesive states.”Under irradiation,the ultrathin black phosphorus nanosheets induced changes in the packing parameters of the HPC assemblies within the Plateau borders and led to coil-to-globule transitions of the HPC and formed unstable liquid films with a“mobile state.”The two interfacial states were reversibly and repeatedly switched by turning the light on and off,which caused rapid bubble coalescence and foam collapse,and we also proved that this destabilizing mechanism was inhibited by cellulose nanocrystals.This work provides an environmentally friendly approach to controlling foam stability,and the proposed strategy can be expanded to the production of multiresponsive fully liquid objects in theory.
