Two-dimensional transition metal porphyrinoid materials(2DTMPoidMats),due to their unique electronic structure and tunable metal active sites,have the potential to enhance interactions with nitrogen molecules and prom...Two-dimensional transition metal porphyrinoid materials(2DTMPoidMats),due to their unique electronic structure and tunable metal active sites,have the potential to enhance interactions with nitrogen molecules and promote the protonation process,making them promising electrochemical nitrogen reduction reaction(eNRR)electrocatalysts.Experimentally screening a large number of catalysts for eNRR catalytic performance would consume considerable time and economic resources.First-principles calculations and machine learning(ML)algorithms could greatly improve the efficiency of catalyst screening.Using this approach,we selected 86 candidates capable of catalyzing eNRR from 1290 types of 2DTMPoidMats,and verified the results with density functional theory(DFT)computations.Analysis of the full reaction pathway shows that MoPp-meso-F-β-Py,MoPp-β-Cl-meso-Diyne,MoPp-meso-Ethinyl,and WPp-β-Pz exhibit the best catalytic performance with the onset potential of-0.22,-0.19,-0.23,and-0.35 V,respectively.This work provides valuable insights into efficient design and screening of eNRR catalysts and promotes the application of ML algorithmic models in the field of catalysis.展开更多
The nanostructure of cementitious materials has important effects on concrete properties. The effects of rice husk ash（RHA） on cement hydration product phases and interfacial transition zone（ITZ） in mortar were in...The nanostructure of cementitious materials has important effects on concrete properties. The effects of rice husk ash（RHA） on cement hydration product phases and interfacial transition zone（ITZ） in mortar were investigated from the nano-scale structure perspective. The experimental results indicate that, with the increase of RHA dosages of samples, the volume fraction of high-density calcium-silicate-hydrate（HD C-S-H） in porosity and hydration product phases increases. The volume fractions of HD C-S-H in C-S-H of samples show an increasing trend with the increase of RHA dosages. RHA decreases the thickness of ITZ and increases the matrix elastic moduli of samples, however, the RHA dosoges hardly affect the thickness and elastic moduli.展开更多
An extreme ultraviolet(EUV) close-up view of the Sun offers unprecedented detail of heating events in the solar corona. Enhanced temporal and spatial images obtained by the Solar Orbiter during its first science perih...An extreme ultraviolet(EUV) close-up view of the Sun offers unprecedented detail of heating events in the solar corona. Enhanced temporal and spatial images obtained by the Solar Orbiter during its first science perihelion enabled us to identify clustered EUV bright tadpoles(CEBTs) occurring near the footpoints of coronal loops.Combining SDO/AIA observations, we determine the altitudes of six distinct CEBTs by stereoscopy, ranging from ~1300 to 3300 km. We then notice a substantial presence of dark, cooler filamentary structures seemingly beneath the CEBTs, displaying periodic up-and-down motions lasting 3–5 minutes. This periodic behavior suggests an association of the majority of CEBTs with Type I spicules. Out of the ten selected CEBTs with fast downward velocity, six exhibit corrected velocities close to or exceeding 50 km s^(-1). These velocities notably surpass the typical speeds of Type I spicules. We explore the generation of such velocities. It indicates that due to the previous limited observations of spicules in the EUV wavelengths, they may reveal novel observational features beyond our current understanding. Gaining insights into these features contributes to a better comprehension of small-scale coronal heating dynamics.展开更多
In recent years,organic-inorganic hybrid materials are widely designed and synthesized as switching materials for temperature response.However,due to the change of molecular arrangement inside the crystal during solid...In recent years,organic-inorganic hybrid materials are widely designed and synthesized as switching materials for temperature response.However,due to the change of molecular arrangement inside the crystal during solid-solid phase transition,the distortion of crystal lattice and the great change of lattice parameters are often caused,which result in a poor repeatability and short life.Thus,designing phase change materials with small lattice changes helps to improve product life.In this article,a novel organic-inorganic hybrid material 3HDMAPAPbBr_(4)(1,3HDMAPA is 3-(hydroxydimethylammonio)propan-1-aminium)was successfully synthesized and characterized.For 1,organic cations filled in the van der Waals gap are connected by hydrogen bonds with halogens in the two-dimensional inorganic layer,forming a stable sandwich structure.During the solid-solid phase transition driven by temperature,the changes of inorganic skeleton are relatively small,and the disorder movement of organic cations does not affect the existence of hydrogen bonds,maintaining a relatively stable crystal structure.In addition,electrical property,optical property and crystal structures are analyzed and discussed in detail.We believe that our work will contribute to the development and application of phase change materials in response materials.展开更多
Due to their limitations in conductivity and shape stability,molten salt phase change materials have encountered obstacles to effectively integrating into electric heating conversion technologies,which are crucial in ...Due to their limitations in conductivity and shape stability,molten salt phase change materials have encountered obstacles to effectively integrating into electric heating conversion technologies,which are crucial in energy storage and conversion fields.In this study,we synthesized an inorganic molten salt composite phase change material(CPCM)with enhanced conductivity and shape stability using a gasphase silica adsorption method.Our findings revealed the regularities in thermal properties modulation by expanded graphite(EG)within CPCM and delved into its characteristics of electric heating conversion.The study elucidated that a conductive network is essentially formed when the EG content exceeds 3 wt%.Following the fabrication of CPCM into electric heating conversion modules,we observed a correlation between the uniformity of module temperature and the quantity of EG,as well as the distribution of electrode resistance and external voltage magnitude.Building upon this observation,we proposed a strategy to adjust the module temperature field with an electric field.Comparing the proposed direct electrical heating energy storage method with traditional indirect electrical heating methods,the energy storage rate increases by 93.8%,with an improved temperature uniformity.This research offers valuable insights for the application of molten salt electric heating conversion CPCMs.展开更多
Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. ...Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. For components operating at high temperatures, temperature measurement is very important. In many situations, the environmental conditions are too hostile for conventional techniques to be used. Researchers over the world have been looking for new techniques for temperature measurement and one such device, called Feroplug, has been developed previously by the and coworkers. The Feroplug has been patented in USA, UK and Europe by the British Technology Group. The underlying principle of the Feroplug is based on the transformation of ferrite in some specially designed duplex stainless steels. This paper describes a new invention called Sigmaplug which is a new development of the Feroplug but using an entirely different physical principle. It was discovered that the sigma phase in Fe展开更多
A sequential of concepts developed in the last decade has enabled a resolution to multiple anomalies of water ice and its low-dimensionality,particularly.Developed concepts include the coupled hydrogen bond(O:H–O)osc...A sequential of concepts developed in the last decade has enabled a resolution to multiple anomalies of water ice and its low-dimensionality,particularly.Developed concepts include the coupled hydrogen bond(O:H–O)oscillator pair,segmental specific heat,three-body coupling potentials,quasisolidity,and supersolidity.Resolved anomalies include ice buoyancy,ice slipperiness,water skin toughness,supercooling and superheating at the nanoscale,etc.Evidence shows consistently that molecular undercoordination shortens the H–O bond and stiffens its phonon while undercoordination does the O:H nonbond contrastingly associated with strong lone pair“:”polarization,which endows the low-dimensional water ice with supersolidity.The supersolid phase is hydrophobic,less dense,viscoelastic,thermally more diffusive,and stable,having longer electron and phonon lifetime.The equal number of lone pairs and protons reserves the configuration and orientation of the coupled O:H–O bonds and restricts molecular rotation and proton hopping,which entitles water the simplest,ordered,tetrahedrally-coordinated,fluctuating molecular crystal covered with a supersolid skin.The O:H–O segmental cooperativity and specific-heat disparity form the soul dictate the extraordinary adaptivity,reactivity,recoverability,and sensitivity of water ice when subjecting to physical perturbation.It is recommended that the premise of“hydrogen bonding and electronic dynamics”would deepen the insight into the core physics and chemistry of water ice.展开更多
Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been c...Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been calculate with heat radiation and heat convection considered.Also a solid lubricant,polytetrafluoroethylene (PTFE) has bee considered to reduce the friction heat effect.The result shows that,there are very strong heat effect while no lubracant considered,the temperature of the bolt joint increased sharply and up to 700℃,which exceed the allowable temperature range of the steel.When PTFE lubricant has been applied,the temperature of the bolt joint increased to 260 ℃,and the bolt steel can by applied in this satuation.These results provide important guidance for the bolt structure modification and material selection.展开更多
The exploration for post-carbon electrode ma- terials for lithium-ion batteries has been a crucial way to satisfy the ever-growing demands for better performance with higher energy/power densities, enhanced safety, an...The exploration for post-carbon electrode ma- terials for lithium-ion batteries has been a crucial way to satisfy the ever-growing demands for better performance with higher energy/power densities, enhanced safety, and longer cycle life. Transition metal oxides have recently re- ceived a great deal of attention as very promising anode materials due to their high theoretical capacity, good safety, eco-benignity, and huge abundance. The present work re- views the latest advances in developing novel transition metal oxides, including FeeO3, Fe3O4, CO3O4, CoO, NiO, MnO, Mn203, Mn3O4, MnO2, MOO3, Cr2O3, Nb2O5, and some binary oxides such as NiCO2O4, ZnCO2O4, MnCO2O4 and CoMn2O4. Nanostructuring and hybrid strategies ap- plicable to transition metal oxides are summarized and analyzed. Furthermore, the impacts of binder choice and heat treatment on electrochemical performance are discussed.展开更多
We report a density functional theory study of a phase transition of a VS2 monolayer that can be tuned by the in-plane biaxial strain. This results in both a metal-insulator transition and a low spin-high spin magneti...We report a density functional theory study of a phase transition of a VS2 monolayer that can be tuned by the in-plane biaxial strain. This results in both a metal-insulator transition and a low spin-high spin magnetic transition. At low temperature, the semiconducting H-phase is stable and large strain （〉3%） is required to provoke the transition. On the other hand, at room temperature （300 K）, only a small tensile strain of 2% is needed to induce the phase transition from the semiconducting H-phase to the metallic T-phase together with the magnetic transition from high spin to low spin. The phase diagram dependence on both strain and temperature is also discussed in order to provide a better understanding of the phase stability of VS2 monolayers.展开更多
Developing efficient and durable non-noble metal-based oxygen evolution catalysts is of great importance for electrochemical water splitting.Here,we report a new and facile strategy for controllable synthesis of high-...Developing efficient and durable non-noble metal-based oxygen evolution catalysts is of great importance for electrochemical water splitting.Here,we report a new and facile strategy for controllable synthesis of high-valence Mo modified FeNiV oxides as efficient OER catalysts.The Mo-dopant displays a significant influence on the valence state of Fe species in the catalysts,which lead to tunable OER performance.When the feed ratio of Mo-dopant is 5%,the Mo-modified FeNiV oxide shows the best OER performance in terms of low overpotential(237 mV at the current density of 10 mA cm^(−2)),Tafel slope(38 mV per decade),and high mass activity,which exceeds its counterparts and most reported OER catalysts.Furthermore,by assembling the catalyst with a carbon fiber cloth,the fabricated water-splitting device exhibits excellent activity and longterm durability in alkaline electrolyte compared with commercial catalysts equipped device.This work not only provides a series of Mo-modified FeNiV-based oxides as high-performance OER catalysts but also offers a new pathway to tune the charge states of OER active centers.展开更多
With the depletion of fossil fuels and environmental pollution, energy storage and conversion have become the focus of current research. Water splitting and fuel cell technologies have made outstanding contributions t...With the depletion of fossil fuels and environmental pollution, energy storage and conversion have become the focus of current research. Water splitting and fuel cell technologies have made outstanding contributions to energy conversion. However, the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have slow kinetics, which limit the capacity of fuel cells. It is of great significance to develop catalysts for the OER and ORR and continuously improve their catalytic performance. Many studies have shown that intrinsic defects, especially vacancies (anion and cation vacancies), can effectively improve the efficiency of electrochemical energy storage and conversion. The introduction of intrinsic defects can generally expose more active sites, enhance conductivity, adjust the electronic state, and promote ion diffusion, thereby enhancing the catalytic performance. This review comprehensively summarizes the latest developments regarding the effects of intrinsic defects on the performance of non-noble metal electrocatalysts. According to the type of intrinsic defect, this article reviews in detail the regulation mechanism, preparation methods and advanced characterization techniques of intrinsic defects in different materials (oxides, non-oxides, etc.). Then, the current difficulties and future development of intrinsic defect regulation are analyzed and discussed thoroughly. Finally, the prospect of intrinsic defects in the field of electrochemical energy storage is further explored.展开更多
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology,the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)+1 种基金the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)supported by the public computing service platform provided by the Network and Computing Center of HUST.
文摘Two-dimensional transition metal porphyrinoid materials(2DTMPoidMats),due to their unique electronic structure and tunable metal active sites,have the potential to enhance interactions with nitrogen molecules and promote the protonation process,making them promising electrochemical nitrogen reduction reaction(eNRR)electrocatalysts.Experimentally screening a large number of catalysts for eNRR catalytic performance would consume considerable time and economic resources.First-principles calculations and machine learning(ML)algorithms could greatly improve the efficiency of catalyst screening.Using this approach,we selected 86 candidates capable of catalyzing eNRR from 1290 types of 2DTMPoidMats,and verified the results with density functional theory(DFT)computations.Analysis of the full reaction pathway shows that MoPp-meso-F-β-Py,MoPp-β-Cl-meso-Diyne,MoPp-meso-Ethinyl,and WPp-β-Pz exhibit the best catalytic performance with the onset potential of-0.22,-0.19,-0.23,and-0.35 V,respectively.This work provides valuable insights into efficient design and screening of eNRR catalysts and promotes the application of ML algorithmic models in the field of catalysis.
基金Funded by the National Natural Science Foundation of China(Nos.51602198,41427802 and 41302257)the Zhejiang Provincial Natural Science Foundation of China(No.LQ13D020001)the Shaoxing University Scientific Research Project(No.20145030)
文摘The nanostructure of cementitious materials has important effects on concrete properties. The effects of rice husk ash（RHA） on cement hydration product phases and interfacial transition zone（ITZ） in mortar were investigated from the nano-scale structure perspective. The experimental results indicate that, with the increase of RHA dosages of samples, the volume fraction of high-density calcium-silicate-hydrate（HD C-S-H） in porosity and hydration product phases increases. The volume fractions of HD C-S-H in C-S-H of samples show an increasing trend with the increase of RHA dosages. RHA decreases the thickness of ITZ and increases the matrix elastic moduli of samples, however, the RHA dosoges hardly affect the thickness and elastic moduli.
基金supported by National Key R&D Program of China Nos. 2022YFF0503800 and 2021YFA0718600the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB0560000)+1 种基金National Natural Science Foundation of China (NSFC, Grant Nos. 12073032, 42274201, 42150105, and 42204176)the Specialized Research Fund for State Key Laboratories of China。
文摘An extreme ultraviolet(EUV) close-up view of the Sun offers unprecedented detail of heating events in the solar corona. Enhanced temporal and spatial images obtained by the Solar Orbiter during its first science perihelion enabled us to identify clustered EUV bright tadpoles(CEBTs) occurring near the footpoints of coronal loops.Combining SDO/AIA observations, we determine the altitudes of six distinct CEBTs by stereoscopy, ranging from ~1300 to 3300 km. We then notice a substantial presence of dark, cooler filamentary structures seemingly beneath the CEBTs, displaying periodic up-and-down motions lasting 3–5 minutes. This periodic behavior suggests an association of the majority of CEBTs with Type I spicules. Out of the ten selected CEBTs with fast downward velocity, six exhibit corrected velocities close to or exceeding 50 km s^(-1). These velocities notably surpass the typical speeds of Type I spicules. We explore the generation of such velocities. It indicates that due to the previous limited observations of spicules in the EUV wavelengths, they may reveal novel observational features beyond our current understanding. Gaining insights into these features contributes to a better comprehension of small-scale coronal heating dynamics.
基金supported by the National Natural Science Foundation of China(22201134)the Natural Science Foundation of Colleges and Universities in Jiangsu Province(22KJB150028).
文摘In recent years,organic-inorganic hybrid materials are widely designed and synthesized as switching materials for temperature response.However,due to the change of molecular arrangement inside the crystal during solid-solid phase transition,the distortion of crystal lattice and the great change of lattice parameters are often caused,which result in a poor repeatability and short life.Thus,designing phase change materials with small lattice changes helps to improve product life.In this article,a novel organic-inorganic hybrid material 3HDMAPAPbBr_(4)(1,3HDMAPA is 3-(hydroxydimethylammonio)propan-1-aminium)was successfully synthesized and characterized.For 1,organic cations filled in the van der Waals gap are connected by hydrogen bonds with halogens in the two-dimensional inorganic layer,forming a stable sandwich structure.During the solid-solid phase transition driven by temperature,the changes of inorganic skeleton are relatively small,and the disorder movement of organic cations does not affect the existence of hydrogen bonds,maintaining a relatively stable crystal structure.In addition,electrical property,optical property and crystal structures are analyzed and discussed in detail.We believe that our work will contribute to the development and application of phase change materials in response materials.
基金This work is supported by National Key R&D Program of China(No.2022YFB2405204).
文摘Due to their limitations in conductivity and shape stability,molten salt phase change materials have encountered obstacles to effectively integrating into electric heating conversion technologies,which are crucial in energy storage and conversion fields.In this study,we synthesized an inorganic molten salt composite phase change material(CPCM)with enhanced conductivity and shape stability using a gasphase silica adsorption method.Our findings revealed the regularities in thermal properties modulation by expanded graphite(EG)within CPCM and delved into its characteristics of electric heating conversion.The study elucidated that a conductive network is essentially formed when the EG content exceeds 3 wt%.Following the fabrication of CPCM into electric heating conversion modules,we observed a correlation between the uniformity of module temperature and the quantity of EG,as well as the distribution of electrode resistance and external voltage magnitude.Building upon this observation,we proposed a strategy to adjust the module temperature field with an electric field.Comparing the proposed direct electrical heating energy storage method with traditional indirect electrical heating methods,the energy storage rate increases by 93.8%,with an improved temperature uniformity.This research offers valuable insights for the application of molten salt electric heating conversion CPCMs.
文摘Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. For components operating at high temperatures, temperature measurement is very important. In many situations, the environmental conditions are too hostile for conventional techniques to be used. Researchers over the world have been looking for new techniques for temperature measurement and one such device, called Feroplug, has been developed previously by the and coworkers. The Feroplug has been patented in USA, UK and Europe by the British Technology Group. The underlying principle of the Feroplug is based on the transformation of ferrite in some specially designed duplex stainless steels. This paper describes a new invention called Sigmaplug which is a new development of the Feroplug but using an entirely different physical principle. It was discovered that the sigma phase in Fe
基金the National Natural Science Foundation of China(Grant No.21875024).
文摘A sequential of concepts developed in the last decade has enabled a resolution to multiple anomalies of water ice and its low-dimensionality,particularly.Developed concepts include the coupled hydrogen bond(O:H–O)oscillator pair,segmental specific heat,three-body coupling potentials,quasisolidity,and supersolidity.Resolved anomalies include ice buoyancy,ice slipperiness,water skin toughness,supercooling and superheating at the nanoscale,etc.Evidence shows consistently that molecular undercoordination shortens the H–O bond and stiffens its phonon while undercoordination does the O:H nonbond contrastingly associated with strong lone pair“:”polarization,which endows the low-dimensional water ice with supersolidity.The supersolid phase is hydrophobic,less dense,viscoelastic,thermally more diffusive,and stable,having longer electron and phonon lifetime.The equal number of lone pairs and protons reserves the configuration and orientation of the coupled O:H–O bonds and restricts molecular rotation and proton hopping,which entitles water the simplest,ordered,tetrahedrally-coordinated,fluctuating molecular crystal covered with a supersolid skin.The O:H–O segmental cooperativity and specific-heat disparity form the soul dictate the extraordinary adaptivity,reactivity,recoverability,and sensitivity of water ice when subjecting to physical perturbation.It is recommended that the premise of“hydrogen bonding and electronic dynamics”would deepen the insight into the core physics and chemistry of water ice.
文摘Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been calculate with heat radiation and heat convection considered.Also a solid lubricant,polytetrafluoroethylene (PTFE) has bee considered to reduce the friction heat effect.The result shows that,there are very strong heat effect while no lubracant considered,the temperature of the bolt joint increased sharply and up to 700℃,which exceed the allowable temperature range of the steel.When PTFE lubricant has been applied,the temperature of the bolt joint increased to 260 ℃,and the bolt steel can by applied in this satuation.These results provide important guidance for the bolt structure modification and material selection.
基金supported by the National Basic Research Program of China(2013CB934103)the National Natural Science Foundation of China(21173054)Science & Technology Commission of Shanghai Municipality(08DZ2270500)
文摘The exploration for post-carbon electrode ma- terials for lithium-ion batteries has been a crucial way to satisfy the ever-growing demands for better performance with higher energy/power densities, enhanced safety, and longer cycle life. Transition metal oxides have recently re- ceived a great deal of attention as very promising anode materials due to their high theoretical capacity, good safety, eco-benignity, and huge abundance. The present work re- views the latest advances in developing novel transition metal oxides, including FeeO3, Fe3O4, CO3O4, CoO, NiO, MnO, Mn203, Mn3O4, MnO2, MOO3, Cr2O3, Nb2O5, and some binary oxides such as NiCO2O4, ZnCO2O4, MnCO2O4 and CoMn2O4. Nanostructuring and hybrid strategies ap- plicable to transition metal oxides are summarized and analyzed. Furthermore, the impacts of binder choice and heat treatment on electrochemical performance are discussed.
文摘We report a density functional theory study of a phase transition of a VS2 monolayer that can be tuned by the in-plane biaxial strain. This results in both a metal-insulator transition and a low spin-high spin magnetic transition. At low temperature, the semiconducting H-phase is stable and large strain （〉3%） is required to provoke the transition. On the other hand, at room temperature （300 K）, only a small tensile strain of 2% is needed to induce the phase transition from the semiconducting H-phase to the metallic T-phase together with the magnetic transition from high spin to low spin. The phase diagram dependence on both strain and temperature is also discussed in order to provide a better understanding of the phase stability of VS2 monolayers.
基金National Natural Science Foundation of China(Nos.52173133,51903178,81971622,and 51803134)the Science and Technology Project of Sichuan Province(2021YFH0135,2020YJ0055,and 2020YFH0087)+4 种基金China Postdoctoral Science Foundation(2021M692303)the Post-Doctor Research Project of Sichuan University(No.2021SCU12013)the 1・3・5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(No.ZYJC21047)Prof.Cheng acknowledges the financial support of the State Key Laboratory of Polymer Materials Engineering(Grant No.sklpme2021-4-02)Fundamental Research Funds for the Central Universities,and Thousand Youth Talents Plan.Dr.S.Li acknowledges the financial support by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Basismodul,Eigene Stelle(LI 3545/1-1).
文摘Developing efficient and durable non-noble metal-based oxygen evolution catalysts is of great importance for electrochemical water splitting.Here,we report a new and facile strategy for controllable synthesis of high-valence Mo modified FeNiV oxides as efficient OER catalysts.The Mo-dopant displays a significant influence on the valence state of Fe species in the catalysts,which lead to tunable OER performance.When the feed ratio of Mo-dopant is 5%,the Mo-modified FeNiV oxide shows the best OER performance in terms of low overpotential(237 mV at the current density of 10 mA cm^(−2)),Tafel slope(38 mV per decade),and high mass activity,which exceeds its counterparts and most reported OER catalysts.Furthermore,by assembling the catalyst with a carbon fiber cloth,the fabricated water-splitting device exhibits excellent activity and longterm durability in alkaline electrolyte compared with commercial catalysts equipped device.This work not only provides a series of Mo-modified FeNiV-based oxides as high-performance OER catalysts but also offers a new pathway to tune the charge states of OER active centers.
基金This work was financially supported by the National Natu-ral Science Foundation of China(12025503,U1867215,11875211,U1932134,12105208)Hubei Provincial Natural Science Foundation(2019CFA036)+1 种基金the Fundamental Research Funds for the Central Universities(2042021kf0068)China Postdoctoral Science Foundation(No.2020M682469).
文摘With the depletion of fossil fuels and environmental pollution, energy storage and conversion have become the focus of current research. Water splitting and fuel cell technologies have made outstanding contributions to energy conversion. However, the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have slow kinetics, which limit the capacity of fuel cells. It is of great significance to develop catalysts for the OER and ORR and continuously improve their catalytic performance. Many studies have shown that intrinsic defects, especially vacancies (anion and cation vacancies), can effectively improve the efficiency of electrochemical energy storage and conversion. The introduction of intrinsic defects can generally expose more active sites, enhance conductivity, adjust the electronic state, and promote ion diffusion, thereby enhancing the catalytic performance. This review comprehensively summarizes the latest developments regarding the effects of intrinsic defects on the performance of non-noble metal electrocatalysts. According to the type of intrinsic defect, this article reviews in detail the regulation mechanism, preparation methods and advanced characterization techniques of intrinsic defects in different materials (oxides, non-oxides, etc.). Then, the current difficulties and future development of intrinsic defect regulation are analyzed and discussed thoroughly. Finally, the prospect of intrinsic defects in the field of electrochemical energy storage is further explored.
