Given the energy demands of the electromobility market,the energy density and safety of lithium batteries(LBs)need to be improved,whereas its cost needs to be decreased.For the enhanced performance and decreased cost,...Given the energy demands of the electromobility market,the energy density and safety of lithium batteries(LBs)need to be improved,whereas its cost needs to be decreased.For the enhanced performance and decreased cost,more suitable electrode and electrolyte materials should be developed based on the improved understanding of the degradation mechanisms and structure–performance correlation in the LB system.Thus,various in situ characterization technologies have been developed during the past decades,providing abundant guidelines on the design of electrode and electrolyte materials.Here we first review the progress of in situ characterization of LBs and emphasize the feature of the multi-model coupling of different characterization techniques.Then,we systematically discuss how in situ characterization technologies reveal the electrochemical processes and fundamental mechanisms of different electrode systems based on representative electrode materials and electrolyte components.Finally,we discuss the current challenges,future opportunities,and possible directions to promote in situ characterization technologies for further improvement of the battery performance.展开更多
Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applica...Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.展开更多
During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other...During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.展开更多
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off...With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.展开更多
To address the limitations of contemporary lithium-ion batteries,particularly their low energy density and safety concerns,all-solid-state lithium batteries equipped with solid-state electrolytes have been identified ...To address the limitations of contemporary lithium-ion batteries,particularly their low energy density and safety concerns,all-solid-state lithium batteries equipped with solid-state electrolytes have been identified as an up-and-coming alternative.Among the various SEs,organic–inorganic composite solid electrolytes(OICSEs)that combine the advantages of both polymer and inorganic materials demonstrate promising potential for large-scale applications.However,OICSEs still face many challenges in practical applications,such as low ionic conductivity and poor interfacial stability,which severely limit their applications.This review provides a comprehensive overview of recent research advancements in OICSEs.Specifically,the influence of inorganic fillers on the main functional parameters of OICSEs,including ionic conductivity,Li+transfer number,mechanical strength,electrochemical stability,electronic conductivity,and thermal stability are systematically discussed.The lithium-ion conduction mechanism of OICSE is thoroughly analyzed and concluded from the microscopic perspective.Besides,the classic inorganic filler types,including both inert and active fillers,are categorized with special emphasis on the relationship between inorganic filler structure design and the electrochemical performance of OICSEs.Finally,the advanced characterization techniques relevant to OICSEs are summarized,and the challenges and perspectives on the future development of OICSEs are also highlighted for constructing superior ASSLBs.展开更多
Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,includi...Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,including weak oxygen adsorption capacity,reliance on sacrificial agents,low charge separation and transfer efficiency.In this regard,doping design and defect engineering have emerged as robust and effective strategies for catalyst modification,particularly through their synergistic effects.Additionally,advanced in situ characterization techniques for investigating reaction mechanisms are gaining momentum.Herein,this review provides a comprehensive analysis of the fundamentals and challenges associated with photocatalytic H_(2)O_(2) production,and highlights the advantages of doping and defect engineering.Subsequently,it outlines preparation methods and applications of these strategies.More importantly,it emphasizes the advanced characterization techniques utilized to validate doping and defects,as well as to investigate underlying mechanisms.Finally,the potential prospects and challenges of this reaction are anticipated.This review aims to offer valuable insights for researchers from both experimental and theoretical perspectives.展开更多
Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modificat...Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.展开更多
Aircrafts damages caused by lightning strikes have been known since the early days of aviation.However,the physical effects on the aircraft structure are still being investigated.This work seeks to evaluate the lightn...Aircrafts damages caused by lightning strikes have been known since the early days of aviation.However,the physical effects on the aircraft structure are still being investigated.This work seeks to evaluate the lightning strike effects in the aluminum alloy 7075-T6.Samples were submitted to lightning strike simulation in laboratory and the damages evaluated through characterization techniques.Ultrasound and profilometry tests have shown material loss to 0.272 mm depth in the damaged region.In addition,it was detected the material accumulation occurrence in the damage vicinity of the region.Below the damage,it was found a region where metallurgical changes were identified.The tensile and microhardness tests results have shown reduction in the percentage elongation and hardness increasing in the material affected by lightning.These results are corroborated by the X-Ray Diffraction(XRD)and Rietveld Method(red line)that indicated an increasing in dislocation density and micro-deformation in the material matrix.Optical microscopy results have shown the presence of microcracks on the normal and cross-section surface of the samples damaged.The Energy Dispersive X-Ray Spectroscopy(EDXS)and Electron Backscattered Diffraction Test(EBSD)found coarse intermetallic phases and precipitates compounds with dimensions greater than 1 lm in length.They were responsible for nucleation of the microcracks that propagate along the material grain boundaries.展开更多
La0.8Sr0.2MnO3-δ (LSM) perovskite was synthesized using different methods, such as solid state reaction, soft-chemical and sol-gel methods for solid oxide fuel cells (SOFCs) for use as a cathode material. The pristin...La0.8Sr0.2MnO3-δ (LSM) perovskite was synthesized using different methods, such as solid state reaction, soft-chemical and sol-gel methods for solid oxide fuel cells (SOFCs) for use as a cathode material. The pristine material was characterized by X-ray diffraction, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). X-ray diffraction results show that the pure phase of La0.8Sr0.2MnO3-δ (LSM) perovskite was formed at 1250oC. Scanning electron microscopy characterization shows that a highly porous material can be obtained using a soft-chemical method with different 3,3’,3”-nitrilotripropionic acid ( NTP) to metal-ion ratio R.展开更多
Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under diffe...Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of CMTs.Porosity and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of geopolymers.Finally,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are compared.The results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,coexist.The solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,respectively.Under a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive strength.The resource utilization of CMT and FA is realized in a more economical way.展开更多
Ammonia(NH_(3))is an important raw material for modern agriculture and industry,being widely demanded to sustain the sustainable development of modern society.Currently,the industrial production methods of NH_(3),such...Ammonia(NH_(3))is an important raw material for modern agriculture and industry,being widely demanded to sustain the sustainable development of modern society.Currently,the industrial production methods of NH_(3),such as the traditional Haber-Bosch process,have drawbacks including high energy consumption and significant carbon dioxide emissions.In recent years,the electrocatalytic nitrate reduction reaction(NO_(3)RR)powered by intermittent renewable energy sources has gradually become a multidisciplinary research hotspot,as it allows for the efficient synthesis of NH_(3)under mild conditions.In this review,we focus on the research of electrocatalysts with atomic-level site,which have attracted attention due to their extremely high atomic utilization efficiency and unique structural characteristics in the field of NO_(3)RR.Firstly,we introduce the mechanism of nitrate reduction for ammonia synthesis and discuss the in-situ characterization techniques related to the mechanism study.Secondly,we review the progress of the electrocatalysts with atomic-level site for nitrate reduction and explore the structure-activity relationship to guide the rational design of efficient catalysts.Lastly,the conclusions of this review and the challenges and prospective of this promising field are presented.展开更多
The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valu...The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valuable insights into the long-term degradation from the perspective of changes in physical and chemical properties,thereby offering a scientific foundation for evaluating advanced materials and strategies.In this review,multidimensional and multi-characterization application scenarios based on ASTs data are systematically summarized.Firstly,the degradation mechanism of catalyst layer(CL)under AST conditions is discussed,with an emphasis on platinum aging and carbon support corrosion.In addition,electrochemical and microphysical characterization tools applicable to different AST test protocols,such as electrochemical surface area(ECSA),electrochemical impedance spectrum(EIS)mapping combined with distribution of relaxation times(DRT),and microscopic physical evolution and tracking techniques for each internal chemical component,are also presented in detail.Finally,through the existing research progress and hotspots,the application prospect of data fusion is elaborated and the important research direction of material optimization and performance prediction based on AST data is emphasized,aiming to provide insights into the study of catalytic layer degradation in fuel cells and promote the continuous development of the field.展开更多
Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and fa...Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and facile synthesis.Currently,the demand for lightweight and longer standby smart portable electronic products drives the development of the upper cut-off voltage of LCO-based batteries to further improve the energy density.However,several challenges,including irreversible structural transformation,surface degradation,cobalt dissolution and oxygen evolution along with detrimental side reactions with the electrolyte remain with charging to a high cut-off voltage(>4.2 V vs.Li/Li+),resulting in rapid capacity decay and safety issues.Based on the degradation mechanisms and latest advances of the high-voltage LCO,this review summarizes modification strategies in view of the LCO structure,artificial interface design and electrolytes optimization.Meanwhile,many advanced characterization and monitoring techniques utilized to clarify the structural and interfacial evolution of LCO during charge/discharge process are critically emphasized.Moreover,the perspectives in terms of integrating multiple modification strategies,applying gel and solid-state electrolytes,optimizing the recovery process and scalable production are presented.展开更多
The development and utilization of renewable clean energy can effectively solve the two major problems of energy and environment. As an efficient power generation device that converts hydrogen energy into electric ene...The development and utilization of renewable clean energy can effectively solve the two major problems of energy and environment. As an efficient power generation device that converts hydrogen energy into electric energy, fuel cell has attracted more and more attention. For fuel cells, the oxygen reduction reaction(ORR) at the cathode is the core reaction, and the design and development of high-performance ORR catalysts remain quite challenging. Since the microenvironment of the active center of single atom catalysts(SACs) has an important influence on its catalytic performance, it has been a research focus to improve the ORR activity and stability of electrocatalysts by adjusting the structure of the active center through reasonable structural regulation methods. In this review, we reviewed the preparation and structure–activity relationship of SACs for ORR. Then, the structural precision regulation methods for improving the activity and stability of ORR electrocatalysts are discussed. And the advanced in-situ characterization techniques for revealing the changes of active sites in the electrocatalytic ORR process are summarized. Finally, the challenges and future design directions of SACs for ORR are discussed. This work will provide important reference value for the design and synthesis of SACs with high activity and stability for ORR.展开更多
Sustainable conversion of carbon dioxide(CO_(2))to high value-added chemicals and fuels is a promising solution to solve the problem of excessive CO_(2) emissions and alleviate the shortage of fossil fuels,maintaining...Sustainable conversion of carbon dioxide(CO_(2))to high value-added chemicals and fuels is a promising solution to solve the problem of excessive CO_(2) emissions and alleviate the shortage of fossil fuels,maintaining the balance of the carbon cycle in nature.The development of catalytic system is of great significance to improve the efficiency and selectivity for electrochemical CO_(2) conversion.In particular,bismuth(Bi)based catalysts are the most promising candidates,while confronting challenges.This review aims to elucidate the fundamental issues of efficient and stable Bi-based catalysts,constructing a bridge between the category,synthesis approach and electrochemical performance.In this review,the categories of Bi-based catalysts are firstly introduced,such as metals,alloys,single atoms,compounds and composites.Followed by the statement of the reliable and versatile synthetic approaches,the representative optimization strategies,such as morphology manipulation,defect engineering,component and heterostructure regulation,have been highlighted in the discussion,paving in-depth insight upon the design principles,reaction activity,selectivity and stability.Afterward,in situ characterization techniques will be discussed to illustrate the mechanisms of electrochemical CO_(2) conversion.In the end,the challenges and perspectives are also provided,promoting a systematic understanding in terms of the bottleneck and opportunities in the field of electrochemical CO_(2) conversion.展开更多
We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectro...We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectroscope. At large wavelengths, devices behave as homogeneous isotropic materials defined by an effective filling factor. The experimental results related to the PhC limited dimensions confirm this characterization.展开更多
We present and demonstrate experimentally a new method for measuring the polarization-mode-dispersion(PMD) of a Chirped Fiber Bragg Grating. The technique has also been applied to accurate chromatic dispersion evaluat...We present and demonstrate experimentally a new method for measuring the polarization-mode-dispersion(PMD) of a Chirped Fiber Bragg Grating. The technique has also been applied to accurate chromatic dispersion evaluation by removing the influence of PMD.展开更多
The complexity of multi-dimensional optical wave dynamics arises from the introduction of multiple degrees of freedom and their intricate interactions.In comparison to multimode spatiotemporal mode-locked solitons,exp...The complexity of multi-dimensional optical wave dynamics arises from the introduction of multiple degrees of freedom and their intricate interactions.In comparison to multimode spatiotemporal mode-locked solitons,expanding the wavelength dimension is also crucial for studying the dynamics of multi-dimensional solitons,with simpler characterization techniques。展开更多
NASICON (Na superionic conductor)-type cathode materials for sodium-ion batteries (SIBs) have attractedextensive attention due to their mechanically robust three-dimensional (3D) framework, which has sufficient opench...NASICON (Na superionic conductor)-type cathode materials for sodium-ion batteries (SIBs) have attractedextensive attention due to their mechanically robust three-dimensional (3D) framework, which has sufficient openchannels for fast Na^(+) transportation. However, they usually suffer from inferior electronic conductivity and lowcapacity, which severely limit their practical applications. To solve these issues, we need to deeply understand thestructural evolution, redox mechanisms, and electrode/electrolyte interface reactions during cycling. Recently,rapid developments in synchrotron X-ray techniques, neutron-based resources, magnetic resonance, as well asoptical and electron microscopy have brought numerous opportunities to gain deep insights into the Na-storagebehaviors of NASICON cathodes. In this review, we summarize the detection principles of advanced characterization techniques used with typical NASICON-structured cathode materials for SIBs. The special focus is on bothoperando and ex situ techniques, which help to investigate the relationships among phase, composition, andvalence variations within electrochemical responses. Fresh electrochemical measurements and theoretical computations are also included to reveal the kinetics and energy-storage mechanisms of electrodes upon charge/discharge. Finally, we describe potential new developments in NASICON-cathodes with optimized SIB systems,foreseeing a bright future for them, achievable through the rational application of advanced diagnostic methods.展开更多
Photocatalytic CO_(2) conversion into valuable hydrocarbon fuels via solar light is a promising strategy to simul-taneously address energy shortage and environmental pollution.However,the photocatalytic CO_(2) reducti...Photocatalytic CO_(2) conversion into valuable hydrocarbon fuels via solar light is a promising strategy to simul-taneously address energy shortage and environmental pollution.However,the photocatalytic CO_(2) reduction performance is too poor to be practically utilized due to the rapid recombination of photogenerated charge carriers.Constructing step-scheme(S-scheme)heterojunction photocatalysts can facilitate the charge separation and maximize the redox ability,thus remarkably enhancing the photocatalytic CO_(2) reduction activity.This review summarizes the progress of S-scheme heterojunction photocatalysts applied in the photocatalytic CO_(2) reduction reactions.Firstly,we introduce the fundamental design principles and characterization methods.The direct and indirect techniques to confirm the S-scheme charge transfer mechanism are disclosed.Secondly,we divide S-scheme composite photocatalyst into the following categories depending on their compositions:g-C_(3)N_(4)-based,metal-chalcogenide-based,TiO_(2)-based,bismuth-based,other metal oxide-based and other semiconductor-based S-scheme photocatalysts.The synergistic effect of the S-scheme charge transfer pathway as well as the unique intrinsic properties of semiconductor materials on the photocatalytic CO_(2) reduction performance is discussed in detail.Finally,concluding perspectives on the challenges and opportunities for the further exploration of highly efficient S-scheme photocatalysts in photocatalytic CO_(2) conversion are presented.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 21820102002, 21931012, 22111530178, 51932001, 51872024, and 51972305)the Cooperation Fund of the Dalian National Laboratory for Clean Energy(DNL), Chinese Academy of Science (CAS) (No. DNL202020)+1 种基金the National Key Research and Development Program of China (No. 2018YFA0703503)the Scientific Instrument Developing Project of the Chinese Academy of Sciences (No. YZ201623)
文摘Given the energy demands of the electromobility market,the energy density and safety of lithium batteries(LBs)need to be improved,whereas its cost needs to be decreased.For the enhanced performance and decreased cost,more suitable electrode and electrolyte materials should be developed based on the improved understanding of the degradation mechanisms and structure–performance correlation in the LB system.Thus,various in situ characterization technologies have been developed during the past decades,providing abundant guidelines on the design of electrode and electrolyte materials.Here we first review the progress of in situ characterization of LBs and emphasize the feature of the multi-model coupling of different characterization techniques.Then,we systematically discuss how in situ characterization technologies reveal the electrochemical processes and fundamental mechanisms of different electrode systems based on representative electrode materials and electrolyte components.Finally,we discuss the current challenges,future opportunities,and possible directions to promote in situ characterization technologies for further improvement of the battery performance.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20170630)the National Natural Science Foundation of China(51802149 and U1801251)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Nanjing University Technology Innovation Fund Project。
文摘Nowadays,in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries.The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies.Hence,we summarize the progress of in-situ/operando techniques employed in rechargeable batteries.The members of this large family are divided into three sections for introduction,including bulk material,electrolyte/electrode interface and gas evolution.In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed.The simultaneous strategies of various in-situ methods are highlighted as well.Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0401503)the National Materials Genome Project of China(Grant No.2016YFB0100106)the National Natural Science Foundation of China(Grant No.11675255)
文摘During the past decades,Li-ion batteries have been one of the most important energy storage devices.Large-scale energy storage requires Li-ion batteries which possess high energy density,low cost,and high safety.Other than advanced battery materials,in-depth understanding of the intrinsic mechanism correlated with cell reaction is also essential for the development of high-performance Li-ion battery.Advanced characterization techniques,especially neutron-based techniques,have greatly promoted Li-ion battery researches.In this review,the characteristics or capabilities of various neutron-based characterization techniques,including elastic neutron scattering,quasi-elastic neutron scattering,neutron imaging,and inelastic neutron scattering,for the related Li-ion-battery researches are summarized.The design of in-situ/operando environment is also discussed.The comprehensive survey on neutron-based characterizations for mechanism understanding will provide guidance for the further study of high-performance Li-ion batteries.
基金financially supported by National Key R&D Program of China(2021YFB3500702)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04).
文摘With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.
基金supported by the National Natural Science Foundation of China(Grant No.22075064,52302234,52272241)Zhejiang Provincial Natural Science Foundation of China under Grant No.LR24E020001+2 种基金Natural Science of Heilongjiang Province(No.LH2023B009)China Postdoctoral Science Foundation(2022M710950)Heilongjiang Postdoctoral Fund(LBH-Z21131),National Key Laboratory Projects(No.SYSKT20230056).
文摘To address the limitations of contemporary lithium-ion batteries,particularly their low energy density and safety concerns,all-solid-state lithium batteries equipped with solid-state electrolytes have been identified as an up-and-coming alternative.Among the various SEs,organic–inorganic composite solid electrolytes(OICSEs)that combine the advantages of both polymer and inorganic materials demonstrate promising potential for large-scale applications.However,OICSEs still face many challenges in practical applications,such as low ionic conductivity and poor interfacial stability,which severely limit their applications.This review provides a comprehensive overview of recent research advancements in OICSEs.Specifically,the influence of inorganic fillers on the main functional parameters of OICSEs,including ionic conductivity,Li+transfer number,mechanical strength,electrochemical stability,electronic conductivity,and thermal stability are systematically discussed.The lithium-ion conduction mechanism of OICSE is thoroughly analyzed and concluded from the microscopic perspective.Besides,the classic inorganic filler types,including both inert and active fillers,are categorized with special emphasis on the relationship between inorganic filler structure design and the electrochemical performance of OICSEs.Finally,the advanced characterization techniques relevant to OICSEs are summarized,and the challenges and perspectives on the future development of OICSEs are also highlighted for constructing superior ASSLBs.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20231342,BK20210867)National Natural Science Foundation of China(22008163)+1 种基金Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE–KF202309)Natural Science Research Project of Higher Education Institutions in Jiangsu Province(21KJB150038).
文摘Hydrogen peroxide(H_(2)O_(2))photosynthesis represents an advanced on-site production method with significant potential for on-demand supply.However,various challenges hinder the efficiency of H_(2)O_(2) yield,including weak oxygen adsorption capacity,reliance on sacrificial agents,low charge separation and transfer efficiency.In this regard,doping design and defect engineering have emerged as robust and effective strategies for catalyst modification,particularly through their synergistic effects.Additionally,advanced in situ characterization techniques for investigating reaction mechanisms are gaining momentum.Herein,this review provides a comprehensive analysis of the fundamentals and challenges associated with photocatalytic H_(2)O_(2) production,and highlights the advantages of doping and defect engineering.Subsequently,it outlines preparation methods and applications of these strategies.More importantly,it emphasizes the advanced characterization techniques utilized to validate doping and defects,as well as to investigate underlying mechanisms.Finally,the potential prospects and challenges of this reaction are anticipated.This review aims to offer valuable insights for researchers from both experimental and theoretical perspectives.
基金supported by The National Key R&D Program of China(No.2021YFB3500700)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04)。
文摘Researchers have recently developed various surface engineering approaches to modify environmental catalysts and improve their catalytic activity.Defect engineering has proved to be one of the most promising modification methods.Constructing defects on the surface of catalytic materials can effectively modulate the coordination environment of the active sites,affecting and changing the electrons,geometry,and other important properties at the catalytic active sites,thus altering the catalytic activity of the catalysts.However,the conformational relationship between defects and catalytic activity remains to be clarified.This dissertation focuses on an overview of recent advances in defect engineering in environmental catalysis.Based on defining the classification of defects in catalytic materials,defect construction methods,and characterization techniques are summarized and discussed.Focusing on an overview of the characteristics of the role of defects in electrocatalytic,photocatalytic,and thermal catalytic reactions and the mechanism of catalytic reactions.An elaborate link is given between the reaction activity and the structure of catalyst defects.Finally,the existing challenges and possible future directions for the application of defect engineering in environmental catalysis are discussed,which are expected to guide the design and development of efficient environmental catalysts and mechanism studies.
文摘Aircrafts damages caused by lightning strikes have been known since the early days of aviation.However,the physical effects on the aircraft structure are still being investigated.This work seeks to evaluate the lightning strike effects in the aluminum alloy 7075-T6.Samples were submitted to lightning strike simulation in laboratory and the damages evaluated through characterization techniques.Ultrasound and profilometry tests have shown material loss to 0.272 mm depth in the damaged region.In addition,it was detected the material accumulation occurrence in the damage vicinity of the region.Below the damage,it was found a region where metallurgical changes were identified.The tensile and microhardness tests results have shown reduction in the percentage elongation and hardness increasing in the material affected by lightning.These results are corroborated by the X-Ray Diffraction(XRD)and Rietveld Method(red line)that indicated an increasing in dislocation density and micro-deformation in the material matrix.Optical microscopy results have shown the presence of microcracks on the normal and cross-section surface of the samples damaged.The Energy Dispersive X-Ray Spectroscopy(EDXS)and Electron Backscattered Diffraction Test(EBSD)found coarse intermetallic phases and precipitates compounds with dimensions greater than 1 lm in length.They were responsible for nucleation of the microcracks that propagate along the material grain boundaries.
基金the Alexander von Humboldt Foundation for a fellowship
文摘La0.8Sr0.2MnO3-δ (LSM) perovskite was synthesized using different methods, such as solid state reaction, soft-chemical and sol-gel methods for solid oxide fuel cells (SOFCs) for use as a cathode material. The pristine material was characterized by X-ray diffraction, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). X-ray diffraction results show that the pure phase of La0.8Sr0.2MnO3-δ (LSM) perovskite was formed at 1250oC. Scanning electron microscopy characterization shows that a highly porous material can be obtained using a soft-chemical method with different 3,3’,3”-nitrilotripropionic acid ( NTP) to metal-ion ratio R.
基金The National Natural Science Foundation of China(No.41877240)Scientific Research Foundation of Graduate School of Southeast University(No.YBPY1930).
文摘Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of CMTs.Porosity and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of geopolymers.Finally,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are compared.The results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,coexist.The solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,respectively.Under a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive strength.The resource utilization of CMT and FA is realized in a more economical way.
基金financial support from the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX24_0690)financial support from the National Natural Science Foundation of China (Project No. 22275088, 52101260)+4 种基金the Project of Shuangchuang Scholar of Jiangsu Province (Project No. JSSCBS20210212)the Fundamental Research Funds for the Central Universities (Project No. 30921011203)the Start-Up Grant (Project No. AE89991/340) from Nanjing University of Science and Technologyfinancial support from the Foundation of Jiangsu Educational Committee (22KJB310008)the Senior Talent Program of Jiangsu University (20JDG073)
文摘Ammonia(NH_(3))is an important raw material for modern agriculture and industry,being widely demanded to sustain the sustainable development of modern society.Currently,the industrial production methods of NH_(3),such as the traditional Haber-Bosch process,have drawbacks including high energy consumption and significant carbon dioxide emissions.In recent years,the electrocatalytic nitrate reduction reaction(NO_(3)RR)powered by intermittent renewable energy sources has gradually become a multidisciplinary research hotspot,as it allows for the efficient synthesis of NH_(3)under mild conditions.In this review,we focus on the research of electrocatalysts with atomic-level site,which have attracted attention due to their extremely high atomic utilization efficiency and unique structural characteristics in the field of NO_(3)RR.Firstly,we introduce the mechanism of nitrate reduction for ammonia synthesis and discuss the in-situ characterization techniques related to the mechanism study.Secondly,we review the progress of the electrocatalysts with atomic-level site for nitrate reduction and explore the structure-activity relationship to guide the rational design of efficient catalysts.Lastly,the conclusions of this review and the challenges and prospective of this promising field are presented.
基金supported by National Natural Science Foundation of China(22279091)Fundamental Funds for the Central Universities。
文摘The catalyst layer is an essential component of fuel cells,exerting a decisive influence on performance,particularly under degradation processes.Characterization derived from accelerated stress tests(ASTs)provide valuable insights into the long-term degradation from the perspective of changes in physical and chemical properties,thereby offering a scientific foundation for evaluating advanced materials and strategies.In this review,multidimensional and multi-characterization application scenarios based on ASTs data are systematically summarized.Firstly,the degradation mechanism of catalyst layer(CL)under AST conditions is discussed,with an emphasis on platinum aging and carbon support corrosion.In addition,electrochemical and microphysical characterization tools applicable to different AST test protocols,such as electrochemical surface area(ECSA),electrochemical impedance spectrum(EIS)mapping combined with distribution of relaxation times(DRT),and microscopic physical evolution and tracking techniques for each internal chemical component,are also presented in detail.Finally,through the existing research progress and hotspots,the application prospect of data fusion is elaborated and the important research direction of material optimization and performance prediction based on AST data is emphasized,aiming to provide insights into the study of catalytic layer degradation in fuel cells and promote the continuous development of the field.
基金financial support from the National Key R&D Program of China(2018YFA0209600)the National Natural Science Foundation of China(22022813 and 21878268)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)。
文摘Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and facile synthesis.Currently,the demand for lightweight and longer standby smart portable electronic products drives the development of the upper cut-off voltage of LCO-based batteries to further improve the energy density.However,several challenges,including irreversible structural transformation,surface degradation,cobalt dissolution and oxygen evolution along with detrimental side reactions with the electrolyte remain with charging to a high cut-off voltage(>4.2 V vs.Li/Li+),resulting in rapid capacity decay and safety issues.Based on the degradation mechanisms and latest advances of the high-voltage LCO,this review summarizes modification strategies in view of the LCO structure,artificial interface design and electrolytes optimization.Meanwhile,many advanced characterization and monitoring techniques utilized to clarify the structural and interfacial evolution of LCO during charge/discharge process are critically emphasized.Moreover,the perspectives in terms of integrating multiple modification strategies,applying gel and solid-state electrolytes,optimizing the recovery process and scalable production are presented.
基金supported by the National Natural Science Foundation of China(Grant No.22108306)the Taishan Scholars Program of Shandong Province(Grant No.tsqn201909065)the Shandong Provincial Natural Science Foundation(Grant Nos.ZR2021YQ15,ZR2020QB174)。
文摘The development and utilization of renewable clean energy can effectively solve the two major problems of energy and environment. As an efficient power generation device that converts hydrogen energy into electric energy, fuel cell has attracted more and more attention. For fuel cells, the oxygen reduction reaction(ORR) at the cathode is the core reaction, and the design and development of high-performance ORR catalysts remain quite challenging. Since the microenvironment of the active center of single atom catalysts(SACs) has an important influence on its catalytic performance, it has been a research focus to improve the ORR activity and stability of electrocatalysts by adjusting the structure of the active center through reasonable structural regulation methods. In this review, we reviewed the preparation and structure–activity relationship of SACs for ORR. Then, the structural precision regulation methods for improving the activity and stability of ORR electrocatalysts are discussed. And the advanced in-situ characterization techniques for revealing the changes of active sites in the electrocatalytic ORR process are summarized. Finally, the challenges and future design directions of SACs for ORR are discussed. This work will provide important reference value for the design and synthesis of SACs with high activity and stability for ORR.
文摘Sustainable conversion of carbon dioxide(CO_(2))to high value-added chemicals and fuels is a promising solution to solve the problem of excessive CO_(2) emissions and alleviate the shortage of fossil fuels,maintaining the balance of the carbon cycle in nature.The development of catalytic system is of great significance to improve the efficiency and selectivity for electrochemical CO_(2) conversion.In particular,bismuth(Bi)based catalysts are the most promising candidates,while confronting challenges.This review aims to elucidate the fundamental issues of efficient and stable Bi-based catalysts,constructing a bridge between the category,synthesis approach and electrochemical performance.In this review,the categories of Bi-based catalysts are firstly introduced,such as metals,alloys,single atoms,compounds and composites.Followed by the statement of the reliable and versatile synthetic approaches,the representative optimization strategies,such as morphology manipulation,defect engineering,component and heterostructure regulation,have been highlighted in the discussion,paving in-depth insight upon the design principles,reaction activity,selectivity and stability.Afterward,in situ characterization techniques will be discussed to illustrate the mechanisms of electrochemical CO_(2) conversion.In the end,the challenges and perspectives are also provided,promoting a systematic understanding in terms of the bottleneck and opportunities in the field of electrochemical CO_(2) conversion.
文摘We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectroscope. At large wavelengths, devices behave as homogeneous isotropic materials defined by an effective filling factor. The experimental results related to the PhC limited dimensions confirm this characterization.
文摘We present and demonstrate experimentally a new method for measuring the polarization-mode-dispersion(PMD) of a Chirped Fiber Bragg Grating. The technique has also been applied to accurate chromatic dispersion evaluation by removing the influence of PMD.
基金National Natural Science Foundation of China(12274238, 62205159, 61835006)Special Project for Cooperation in Basic Research of Beijing,Tianjin and Hebei (21JCZXJC00010)
文摘The complexity of multi-dimensional optical wave dynamics arises from the introduction of multiple degrees of freedom and their intricate interactions.In comparison to multimode spatiotemporal mode-locked solitons,expanding the wavelength dimension is also crucial for studying the dynamics of multi-dimensional solitons,with simpler characterization techniques。
基金Financial support from the National Natural Science Foundation of China(22075016 and 21805007)Fundamental Research Funds for the Central Universities(FRF-TP-20-020A3)111 Project(B12015 and B170003)is gratefully acknowledged.
文摘NASICON (Na superionic conductor)-type cathode materials for sodium-ion batteries (SIBs) have attractedextensive attention due to their mechanically robust three-dimensional (3D) framework, which has sufficient openchannels for fast Na^(+) transportation. However, they usually suffer from inferior electronic conductivity and lowcapacity, which severely limit their practical applications. To solve these issues, we need to deeply understand thestructural evolution, redox mechanisms, and electrode/electrolyte interface reactions during cycling. Recently,rapid developments in synchrotron X-ray techniques, neutron-based resources, magnetic resonance, as well asoptical and electron microscopy have brought numerous opportunities to gain deep insights into the Na-storagebehaviors of NASICON cathodes. In this review, we summarize the detection principles of advanced characterization techniques used with typical NASICON-structured cathode materials for SIBs. The special focus is on bothoperando and ex situ techniques, which help to investigate the relationships among phase, composition, andvalence variations within electrochemical responses. Fresh electrochemical measurements and theoretical computations are also included to reveal the kinetics and energy-storage mechanisms of electrodes upon charge/discharge. Finally, we describe potential new developments in NASICON-cathodes with optimized SIB systems,foreseeing a bright future for them, achievable through the rational application of advanced diagnostic methods.
基金This work was supported by the NSFC(22002091,22272110,22178224)the Fundamental Research Funds for Shenzhen Technology University(20211063010047)+5 种基金Guangdong Basic and Applied Basic Research Foundation(2020A1515110873)the University Engineering Research Center of Crystal Growth and Applications of Guangdong Province(2020GCZX005)Shenzhen Fundamental Research Program(JCYJ20190813113408912)Natural Science Foundation of Top Talent of SZTU(2019211)Shenzhen Stable Supporting Program(SZWD2021015,20220716001753001)Science and Technology Project from Guangdong Department of Education(2021ZDJS110).
文摘Photocatalytic CO_(2) conversion into valuable hydrocarbon fuels via solar light is a promising strategy to simul-taneously address energy shortage and environmental pollution.However,the photocatalytic CO_(2) reduction performance is too poor to be practically utilized due to the rapid recombination of photogenerated charge carriers.Constructing step-scheme(S-scheme)heterojunction photocatalysts can facilitate the charge separation and maximize the redox ability,thus remarkably enhancing the photocatalytic CO_(2) reduction activity.This review summarizes the progress of S-scheme heterojunction photocatalysts applied in the photocatalytic CO_(2) reduction reactions.Firstly,we introduce the fundamental design principles and characterization methods.The direct and indirect techniques to confirm the S-scheme charge transfer mechanism are disclosed.Secondly,we divide S-scheme composite photocatalyst into the following categories depending on their compositions:g-C_(3)N_(4)-based,metal-chalcogenide-based,TiO_(2)-based,bismuth-based,other metal oxide-based and other semiconductor-based S-scheme photocatalysts.The synergistic effect of the S-scheme charge transfer pathway as well as the unique intrinsic properties of semiconductor materials on the photocatalytic CO_(2) reduction performance is discussed in detail.Finally,concluding perspectives on the challenges and opportunities for the further exploration of highly efficient S-scheme photocatalysts in photocatalytic CO_(2) conversion are presented.
