Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inhere...Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inherent activity and incompatibility of the individual components themselves,and the irregular charge distribution and slow charge transfer ability between interfaces severely limit the activity of UOR.Therefore,we optimized and designed a Ni_(2)P/CoP interface with modulated surface charge distribution and directed charge transfer to promote UOR activity.Density functional theorycalculations first predict a regular charge transfer from CoP to Ni_(2)P,which creates a built-in electric field between Ni_(2)P and CoP interface.Optimization of the adsorption/desorption process of UOR/HER reaction intermediates leads to the improvement of catalytic activity.Electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy characterization confirm the unique mechanism of facilitated reaction at the Ni_(2)P/CoP interface.Electrochemical tests further validated the prediction with excellent UOR/HER activities of 1.28 V and 19.7 mV vs.RHE,at 10 mA cm^(-2),respectively.Furthermore,Ni_(2)P/CoP achieves industrial-grade current densities(500 mA cm^(−2))at 1.75 V and 1.87 V in the overall urea electrolyzer(UOR||HER)and overall human urine electrolyzer(HUOR||HER),respectively,and demonstrates considerable durability.展开更多
Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors...Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors are essential for forming a continuous and effective physical contact region between the electrolyte and the electrode and require further detailed understanding.Here,a case study on 1 T-2 H phase molybdenum disulfide(Mo S_(2))/carbon fiber paper(CFP)catalytic electrodes is performed.Rapid gas-liquid mass transfer at the interface for enhancing the working area stability and capillarity for increasing the electrode working area is found.The real scenario,wherein the energy utilization efficiency of the as-prepared non-noble metal catalytic electrode exceeds that of the noble metal catalytic electrode,is disclosed.Specifically,a fluid dynamics model is developed to investigate the behavior mechanism of hydrogen bubbles from generation to desorption on the catalytic electrode surface with different hydrophilic and hydrophobic properties.These new insights and theoretical evidence on the non-negligible three-phase interface behaviors will identify opportunities and motivate future research in high-efficiency,stability,and low-cost HER catalytic electrode development.展开更多
To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring art...To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary(VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam.However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes,combination quality of the RCC layers should be significantly ensured.展开更多
The construction interfaces of RCCD have a distinct influence on the deformation of dams. The characters and rules on deformation of construction interfaces are studied. The methods simulating the deformation of the i...The construction interfaces of RCCD have a distinct influence on the deformation of dams. The characters and rules on deformation of construction interfaces are studied. The methods simulating the deformation of the interfaces at different stages are proposed. A thickness analytic model and a no-thickness analytic model of construction interfaces are built. These models can reflect the elastic deformation, the attenuation creep deformation, the irreversible creep deformation and the accelerating creep defor- mation of interfaces. The example shows that these proposed models can simulate the deformation of the dam structure objectively. Especially, the results of the thickness analytic model which simulates the gradual changing regularities of interfaces can tally with those of monitoring in situ preferably. The methods proposed and the analytic models can be generalized and applied to general concrete dams, especially to the analysis on deformation rules of fault and interlayer in dam base.展开更多
Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed t...Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.展开更多
Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial...Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial-level current density due to high concentration of salts and compete reaction of chlorine evolution.Herein,a 1D NiFe_(2)O_(4)/NiMoO_(4) heterostructure as a bifunctional electrocatalyst for overall seawater splitting is constructed by combining NiMoO_(4) nanowires with NiFe_(2)O_(4)nanoparticles on carbon felt(CF)by a simple hydrothermal,impregnation and calcination method.The electrocatalyst exhibits low overpotential of 237 and 292 mV for oxygen evolution reaction and hydrogen evolution reaction at 400 m A/cm^(2)in the alkaline seawater(1 mol/L KOH+0.5 mol/L NaCl)due to the plentiful interfaces of NiFe_(2)O_(4)/NiMoO_4 which exposes more active sites and expands the active surface area,thereby enhancing its intrinsic activity and promoting the reaction kinetics.Notably,it displays low voltages of 1.95 V to drive current density of 400 m A/cm^(2)in alkaline seawater with its excellent stability of 200 h at above 100 m A/cm^(2),exhibiting outstanding performance and good corrosion resistance.This work provides an effective strategy for constructing efficient and cost-effective electrocatalysts for industrial seawater electrolysis,underscoring its potential for sustainable energy applications.展开更多
Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavora...Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavorable interface that largely determines the reaction efficiency and selectivity.Here we present an in situ dynamic reconstruction strategy to enhance the NO_(3)^(-)RR by constructing Cu/Ce(OH)_(x)catalyst with abundant interfacial active sites.The Cu/Ce(OH)_(x)catalyst was in situ formed through dynamic reconstruction of Cu_(2)Cl(OH)_(3)/Ce(OH)_(x)heterostructure during electrochemical NO_(3)^(‒)RR process.The catalyst exhibits high performance with NO_(3)^(-)conversion of 100.0%,NH_(3)selectivity of 97.8%,NH_(3)Faradaic efficiency of 99.2%and long stability,which is among the state-of-the-art catalysts in neutral media.Both experimental and theoretical results demonstrate that the Cu and Ce sites at the interface can operate cooperatively to promote the adsorption and activation of NO_(3)^(-),and lower the formation energy of key intermediate*HNO.Meanwhile,the hydrogen evolution reaction is also greatly suppressed due to the high H*binding strength at the interface.The strategy can be extended to other catalytic systems and opens a new avenue for the design of efficient electrocatalysts.展开更多
High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modifi...High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modification strategy to develop a low-cost and efficient electrocatalyst for water splitting.The synthesized mulberry-like NiS/Ni nanoparticles exhibit excellent catalytic performance for water splitting.Small overpotentials of 301 and 161 mV are needed to drive the current density of 10 mA cm^-2 accompanying with remarkably low Tafel slopes of 46 and 74 mV dec^-1 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively.Meanwhile,a robust electrochemical stability is demonstrated.Further high-resolution X-ray photoelectron spectroscopy analyses reveal that the intrinsic HER activity improvement is attributed to the electron-enriched S on the strongly coupled NiS and Ni interface,which simultaneously facilitates the important electron transfer,consistent with the electrochemical impedance results.The post characterizations demonstrate that surface reconstructed oxyhydroxide contributes to the OER activity and NiS/Ni is an OER precatalyst.This structure construction with in-situ formation of active interface provides an effective way to design efficient electrocatalysts for energy conversion.展开更多
Reinforced concrete (RC) constructions are the innovation of sustainable constructions replacing masonry constructions. Despite this, the use of concrete and steel to improve the performance of structural members in s...Reinforced concrete (RC) constructions are the innovation of sustainable constructions replacing masonry constructions. Despite this, the use of concrete and steel to improve the performance of structural members in service is a recurring problem due to the immediate or overtime appearance of cracks. The objective of this work was therefore to assess the damage phenomena of the steel-concrete interface in order to assess the performance of an RC structure. Samples of approximately 30 cm of reinforcement attacked by rust were taken from broken reinforced concrete columns and beams in order to determine the impact of corrosion on high adhesion steel (HA) and therefore on its ability to resist. The experimental results have shown that the corrosion degradation rates of reinforcing bars of different diameters increase as the diameter of the reinforcing bars decreases: 5% for HA12;23.75% for HA8 and 50% for HA6. Using the approach proposed by Mangat and Elgalf on the bearing capacity as a function of the progress of the corrosion phenomenon, these rates made it possible to assess the new fracture limits of corroded HA steels. For HA6 respectively HA8 and HA12, their initial limit resistances will decrease by 4/4, 3/4 and 1/4. Based on the results of this study and in order to guarantee their durability, an RC structure can be dimensioned by taking into account the effects of reinforcement corrosion.展开更多
The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performanc...The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performance indexes were verified by tests. The experimental results show that the adhesive capability of interface is improved effectively by using SZC material, the properties, such as anti-freezing, erosion-resistance and anti-shrinkage are improved greatly as well as durability.展开更多
Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between mar...Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.展开更多
Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic t...Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.展开更多
The use of seawater-based electrolytes in zinc-air batteries(S-ZABs)presents significant economic and social benefits and mitigates the demand for scarce freshwater resources.However,it is challenging to achieve a met...The use of seawater-based electrolytes in zinc-air batteries(S-ZABs)presents significant economic and social benefits and mitigates the demand for scarce freshwater resources.However,it is challenging to achieve a metal^(-)nitrogen-carbon(M-N-C)catalyst that exhibits high resistance to corrosive Cl^(-)in seawater-based electrolytes and possesses a strengthened binding affinity with O_(2),which enables catalysts with an optimized oxygen reduction reaction(ORR)and enhances the applicability of S-ZABs.Herein,we propose a combined wet chemistry-pyrolysis strategy to obtain atomically dispersed Fe-decorated nitrogen-doped mesoporous carbon spheres(N-MCS-Fe-900).Benefiting from the capacity of the Fe decorations to form the edge-hosted aerophilic FeN_(4)-O_(2)sites at the optimized three-phase interface,N-MCS-Fe-900 affords the enhanced resistance of the active Fe sites to corrosive Cl^(-),as well as improved interaction with O_(2),thereby facilitating the ORR process.As expected,the N-MCS-Fe-900 delivers high half wave potential of 0.90 V and kinetic current density of 18.61 mA cm^(-2)at 0.85 V in seawater-based 0.1 M KOH.More importantly,the S-ZABs equipped with N-MCS-Fe-900 exhibited long-term stability under a high current density for over 140 h without voltage decay.Theoretical calculations and electrochemical performance evaluations collectively revealed the superior catalytic efficacy and genesis of this activity in N-MCS-Fe-900,which features edge-hosted FeN_(4)-O_(2)sites at the stable three-phase interface in seawater electrolytes.This study provides new insights for the advancement of ORR catalysts in sustainable energy conversion technologies for seawater-based electrolytes.展开更多
The construction of structures with multiple interfaces and dielectric/magnetic heterostructures enables the design of materials with unique physical and chemical properties,which has aroused intensive interest in sci...The construction of structures with multiple interfaces and dielectric/magnetic heterostructures enables the design of materials with unique physical and chemical properties,which has aroused intensive interest in scientific and technological fields.Especially,for electromagnetic(EM)wave absorption,enhanced interface polarization and improved impedence match with high Snoek's limitation could be achieved by multiple interfaces and dielectric/magnetic heterostructures,respectively,which are benificial to high-efficiency electromagnetic wave absorption(EWA).However,by far,the principles in the design or construction of structures with multiple interfaces and dielectric/magnetic heterostructures,and the relationships between those structures or heterostructures and their EWA performance have not been fully summarized and reviewed.This article aims to provide a timely review on the research progresses of high-efficency EM wave absorbers with multiple interfaces and dielectric/magnetic heterostructures,focusing on various promising EWA materials.Particularly,EM attenuation mechanisms in those structures with multiple interfaces and dielectric/magnetic heterostructures are discussed and generalized.Furthermore,the changllenges and future developments of EM wave absorbers based on those structures are proposed.展开更多
Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different challenges.Crucially,the theoretical mechanics of wet adhesives has never been s...Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different challenges.Crucially,the theoretical mechanics of wet adhesives has never been sufficiently revealed.Here,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive systems.Micro-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface notably.Subsequently,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee arolium.The results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism effects.Under these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact zone.Notably,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of honeybees.These works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.展开更多
文摘Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inherent activity and incompatibility of the individual components themselves,and the irregular charge distribution and slow charge transfer ability between interfaces severely limit the activity of UOR.Therefore,we optimized and designed a Ni_(2)P/CoP interface with modulated surface charge distribution and directed charge transfer to promote UOR activity.Density functional theorycalculations first predict a regular charge transfer from CoP to Ni_(2)P,which creates a built-in electric field between Ni_(2)P and CoP interface.Optimization of the adsorption/desorption process of UOR/HER reaction intermediates leads to the improvement of catalytic activity.Electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy characterization confirm the unique mechanism of facilitated reaction at the Ni_(2)P/CoP interface.Electrochemical tests further validated the prediction with excellent UOR/HER activities of 1.28 V and 19.7 mV vs.RHE,at 10 mA cm^(-2),respectively.Furthermore,Ni_(2)P/CoP achieves industrial-grade current densities(500 mA cm^(−2))at 1.75 V and 1.87 V in the overall urea electrolyzer(UOR||HER)and overall human urine electrolyzer(HUOR||HER),respectively,and demonstrates considerable durability.
基金supported by the National Natural Science Foundation of China(No.62004051)the Natural Science Foundation of Heilongjiang province(No.LH2020F013)+1 种基金the China Postdoctoral Science Fund(No.2020M670909)the Heilongjiang Postdoctoral Science Fund(No.LBH-Z19017)。
文摘Hydrogen evolution reaction(HER)catalytic electrodes under actual working conditions show interesting mass transfer behaviors at solid(electrode)/liquid(electrolyte)/gas(hydrogen)three-phase interfaces.These behaviors are essential for forming a continuous and effective physical contact region between the electrolyte and the electrode and require further detailed understanding.Here,a case study on 1 T-2 H phase molybdenum disulfide(Mo S_(2))/carbon fiber paper(CFP)catalytic electrodes is performed.Rapid gas-liquid mass transfer at the interface for enhancing the working area stability and capillarity for increasing the electrode working area is found.The real scenario,wherein the energy utilization efficiency of the as-prepared non-noble metal catalytic electrode exceeds that of the noble metal catalytic electrode,is disclosed.Specifically,a fluid dynamics model is developed to investigate the behavior mechanism of hydrogen bubbles from generation to desorption on the catalytic electrode surface with different hydrophilic and hydrophobic properties.These new insights and theoretical evidence on the non-negligible three-phase interface behaviors will identify opportunities and motivate future research in high-efficiency,stability,and low-cost HER catalytic electrode development.
基金Projects(20120094110005,20120094130003)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProjects(51379068,51139001,51279052,51209077,51179066)supported by the National Natural Science Foundation of China+1 种基金Project(NCET-11-0628)supported by the Program for New Century Excellent Talents in University,ChinaProjects(201201038,201101013)supported by the Public Welfare Industry Research Special Fund Project of Ministry of Water Resources of China
文摘To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary(VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam.However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes,combination quality of the RCC layers should be significantly ensured.
基金Project supported by the National Natural Science Foundation of China (Nos.50539010, 50579010)the "948" Project of Ministry of Water Resoures (No.CT200612)the Major State Basic Research Development Program of China (973 Program) (No.2002CB412707)
文摘The construction interfaces of RCCD have a distinct influence on the deformation of dams. The characters and rules on deformation of construction interfaces are studied. The methods simulating the deformation of the interfaces at different stages are proposed. A thickness analytic model and a no-thickness analytic model of construction interfaces are built. These models can reflect the elastic deformation, the attenuation creep deformation, the irreversible creep deformation and the accelerating creep defor- mation of interfaces. The example shows that these proposed models can simulate the deformation of the dam structure objectively. Especially, the results of the thickness analytic model which simulates the gradual changing regularities of interfaces can tally with those of monitoring in situ preferably. The methods proposed and the analytic models can be generalized and applied to general concrete dams, especially to the analysis on deformation rules of fault and interlayer in dam base.
基金Item Sponsored by the National Natural Science Foundation of China[NO.50934005 and NO.50904014]
文摘Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.
基金supported by the National Natural Science Foundation of China(No.51908408)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2019KJ008)Basic Research Program of Jiangsu Province(No.BK20241845)。
文摘Direct seawater electrolysis is a promising way for hydrogen energy production.However,developing efficient and cost-effective electrocatalysts remains a significant challenge for seawater electrolysis with industrial-level current density due to high concentration of salts and compete reaction of chlorine evolution.Herein,a 1D NiFe_(2)O_(4)/NiMoO_(4) heterostructure as a bifunctional electrocatalyst for overall seawater splitting is constructed by combining NiMoO_(4) nanowires with NiFe_(2)O_(4)nanoparticles on carbon felt(CF)by a simple hydrothermal,impregnation and calcination method.The electrocatalyst exhibits low overpotential of 237 and 292 mV for oxygen evolution reaction and hydrogen evolution reaction at 400 m A/cm^(2)in the alkaline seawater(1 mol/L KOH+0.5 mol/L NaCl)due to the plentiful interfaces of NiFe_(2)O_(4)/NiMoO_4 which exposes more active sites and expands the active surface area,thereby enhancing its intrinsic activity and promoting the reaction kinetics.Notably,it displays low voltages of 1.95 V to drive current density of 400 m A/cm^(2)in alkaline seawater with its excellent stability of 200 h at above 100 m A/cm^(2),exhibiting outstanding performance and good corrosion resistance.This work provides an effective strategy for constructing efficient and cost-effective electrocatalysts for industrial seawater electrolysis,underscoring its potential for sustainable energy applications.
文摘Electrocatalytic nitrate reduction(NO_(3)^(-)RR)offers a promising technique for the removal and utilization of nitrate in water.However,the performance of current catalysts is still limited mainly due to the unfavorable interface that largely determines the reaction efficiency and selectivity.Here we present an in situ dynamic reconstruction strategy to enhance the NO_(3)^(-)RR by constructing Cu/Ce(OH)_(x)catalyst with abundant interfacial active sites.The Cu/Ce(OH)_(x)catalyst was in situ formed through dynamic reconstruction of Cu_(2)Cl(OH)_(3)/Ce(OH)_(x)heterostructure during electrochemical NO_(3)^(‒)RR process.The catalyst exhibits high performance with NO_(3)^(-)conversion of 100.0%,NH_(3)selectivity of 97.8%,NH_(3)Faradaic efficiency of 99.2%and long stability,which is among the state-of-the-art catalysts in neutral media.Both experimental and theoretical results demonstrate that the Cu and Ce sites at the interface can operate cooperatively to promote the adsorption and activation of NO_(3)^(-),and lower the formation energy of key intermediate*HNO.Meanwhile,the hydrogen evolution reaction is also greatly suppressed due to the high H*binding strength at the interface.The strategy can be extended to other catalytic systems and opens a new avenue for the design of efficient electrocatalysts.
基金This work was financailly supported by the National Natural Science Foundation of China(Nos.51722204 and 51802145)the National Key Basic Research Program of China(No.2014CB931702)+2 种基金the Sichuan Science and Technology Program(Nos.2018RZ0082 and 2019JDRC0070)the Fundamental Research Fund for the Central Universities(No.A03018023801053)the Open Project of Jiangsu Key Laboratory for Carbon-Based Functional Materials Devices at Soochow University(No.KJS1807).
文摘High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modification strategy to develop a low-cost and efficient electrocatalyst for water splitting.The synthesized mulberry-like NiS/Ni nanoparticles exhibit excellent catalytic performance for water splitting.Small overpotentials of 301 and 161 mV are needed to drive the current density of 10 mA cm^-2 accompanying with remarkably low Tafel slopes of 46 and 74 mV dec^-1 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively.Meanwhile,a robust electrochemical stability is demonstrated.Further high-resolution X-ray photoelectron spectroscopy analyses reveal that the intrinsic HER activity improvement is attributed to the electron-enriched S on the strongly coupled NiS and Ni interface,which simultaneously facilitates the important electron transfer,consistent with the electrochemical impedance results.The post characterizations demonstrate that surface reconstructed oxyhydroxide contributes to the OER activity and NiS/Ni is an OER precatalyst.This structure construction with in-situ formation of active interface provides an effective way to design efficient electrocatalysts for energy conversion.
文摘Reinforced concrete (RC) constructions are the innovation of sustainable constructions replacing masonry constructions. Despite this, the use of concrete and steel to improve the performance of structural members in service is a recurring problem due to the immediate or overtime appearance of cracks. The objective of this work was therefore to assess the damage phenomena of the steel-concrete interface in order to assess the performance of an RC structure. Samples of approximately 30 cm of reinforcement attacked by rust were taken from broken reinforced concrete columns and beams in order to determine the impact of corrosion on high adhesion steel (HA) and therefore on its ability to resist. The experimental results have shown that the corrosion degradation rates of reinforcing bars of different diameters increase as the diameter of the reinforcing bars decreases: 5% for HA12;23.75% for HA8 and 50% for HA6. Using the approach proposed by Mangat and Elgalf on the bearing capacity as a function of the progress of the corrosion phenomenon, these rates made it possible to assess the new fracture limits of corroded HA steels. For HA6 respectively HA8 and HA12, their initial limit resistances will decrease by 4/4, 3/4 and 1/4. Based on the results of this study and in order to guarantee their durability, an RC structure can be dimensioned by taking into account the effects of reinforcement corrosion.
文摘The new adhesive material for the construction joints of tunnel lining(named as SZC) was studied based on the structural characteristics of interfaces and the characteristic of bonding construction, and the performance indexes were verified by tests. The experimental results show that the adhesive capability of interface is improved effectively by using SZC material, the properties, such as anti-freezing, erosion-resistance and anti-shrinkage are improved greatly as well as durability.
基金supported by a grant from the National Natural Science Foundations of China(No.52171282)supported by Taishan Scholars Program of Shandong Province,China(No.tsqn202306098)the Shandong Provincial Key Research and Development Plan,China(No.2021ZLGX04).
文摘Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL)approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.
文摘Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li<sup> </sup>. Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO<sub>4</sub>, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.
基金supported by the National Natural Science Foundation of China(22309197,22279124,and 52261145700)the Natural Science Foundation of Shandong Province(ZR2022ZD30).
文摘The use of seawater-based electrolytes in zinc-air batteries(S-ZABs)presents significant economic and social benefits and mitigates the demand for scarce freshwater resources.However,it is challenging to achieve a metal^(-)nitrogen-carbon(M-N-C)catalyst that exhibits high resistance to corrosive Cl^(-)in seawater-based electrolytes and possesses a strengthened binding affinity with O_(2),which enables catalysts with an optimized oxygen reduction reaction(ORR)and enhances the applicability of S-ZABs.Herein,we propose a combined wet chemistry-pyrolysis strategy to obtain atomically dispersed Fe-decorated nitrogen-doped mesoporous carbon spheres(N-MCS-Fe-900).Benefiting from the capacity of the Fe decorations to form the edge-hosted aerophilic FeN_(4)-O_(2)sites at the optimized three-phase interface,N-MCS-Fe-900 affords the enhanced resistance of the active Fe sites to corrosive Cl^(-),as well as improved interaction with O_(2),thereby facilitating the ORR process.As expected,the N-MCS-Fe-900 delivers high half wave potential of 0.90 V and kinetic current density of 18.61 mA cm^(-2)at 0.85 V in seawater-based 0.1 M KOH.More importantly,the S-ZABs equipped with N-MCS-Fe-900 exhibited long-term stability under a high current density for over 140 h without voltage decay.Theoretical calculations and electrochemical performance evaluations collectively revealed the superior catalytic efficacy and genesis of this activity in N-MCS-Fe-900,which features edge-hosted FeN_(4)-O_(2)sites at the stable three-phase interface in seawater electrolytes.This study provides new insights for the advancement of ORR catalysts in sustainable energy conversion technologies for seawater-based electrolytes.
基金The authors are grateful for financial support from the National Key R&D Program of China(2019YFB2204500)the National Natural Science Foundation of China(Grants 51772160,51977009)Postdoctoral Research Foundation of China(2020SA0017).
文摘The construction of structures with multiple interfaces and dielectric/magnetic heterostructures enables the design of materials with unique physical and chemical properties,which has aroused intensive interest in scientific and technological fields.Especially,for electromagnetic(EM)wave absorption,enhanced interface polarization and improved impedence match with high Snoek's limitation could be achieved by multiple interfaces and dielectric/magnetic heterostructures,respectively,which are benificial to high-efficiency electromagnetic wave absorption(EWA).However,by far,the principles in the design or construction of structures with multiple interfaces and dielectric/magnetic heterostructures,and the relationships between those structures or heterostructures and their EWA performance have not been fully summarized and reviewed.This article aims to provide a timely review on the research progresses of high-efficency EM wave absorbers with multiple interfaces and dielectric/magnetic heterostructures,focusing on various promising EWA materials.Particularly,EM attenuation mechanisms in those structures with multiple interfaces and dielectric/magnetic heterostructures are discussed and generalized.Furthermore,the changllenges and future developments of EM wave absorbers based on those structures are proposed.
基金supported by the National Key R&D Program of China(2021YFB3400200)the Beijing Natural Science Foundation(3212012)+2 种基金the National Natural Science Foundation of China(52075038)the Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(KF20200001)the Opening Project of State Key Laboratory of Tribology,Tsinghua University(SKLTKF20B06)。
文摘Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different challenges.Crucially,the theoretical mechanics of wet adhesives has never been sufficiently revealed.Here,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive systems.Micro-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface notably.Subsequently,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee arolium.The results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism effects.Under these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact zone.Notably,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of honeybees.These works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.
