Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconduc...Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.展开更多
Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivat...Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.展开更多
Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affecte...Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affected by the built-in electric field of the heterostructure.In this study,P/N co-doped carbon-coated NiCo/Ni-CoO heterostructure was prepared by in situ acid etching,aniline polymerization,and pyrolysis.This method can form a tightly connected heterogeneous interface.It was found that introducing P-O bonds in the carbon shell can increase its work function,thereby enhancing the built-in electric field between the carbon shell and the core catalyst.Detailed characterizations confirm that the P-O bridge at the heterogeneous interface can provide an electron flow highway from the core to the shell.The generated carbon defects generated by P leaching during surface reconstruction also have strong electronabsorbing capacity.These effects promote the conversion of Co^(2+)to Co^(3+),thereby providing more highly active sites.The resulting catalyst shows significantly enhanced activity and stability.This study demonstrates the promoting effect of the built-in electric field on the surface reconstruction of the catalyst and emphasizes the importance of the construction of tightly connected heterogeneous interface,which is instructive for the design of excellent OER catalysts.展开更多
Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ recons...Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ reconstructed and converted into high-valence metal oxyhydroxides.However,a limited understanding of the effects of electro-oxidation and anion leaching has resulted in insufficient theoretical guidance for the rational design of efficient catalysts.Herein,FeSe@NiSe nanorods were fabricated for the OER using a facile hydrothermal selenization method supported on FeNi foam.In-situ Raman spectroscopy and multiple characterization techniques were employed to elucidate the mechanism of FeSe@NiSe surface evolution.Metal cations on the catalyst surface were reconstructed and converted into OER-active species Fe/NiOOH at low potential.As the applied potential increased,electro-oxidation and leaching of Se occurred,resulting in SeO_(4)^(2−)adsorption on the catalyst surface,which further enhanced catalytic activity.As a result,the reconstructed FeSe@NiSe/iron-nickel foam(INF)exhibited exceptional catalytic activity for OER,achieving an ultralow overpotential of 283 mV at a current density of 100 mA·cm^(−2).Notably,the bifunctional FeSe@NiSe/INF electrode facilitated overall water splitting,affording a current density of 10 mA·cm^(−2) only at 1.53 V,even superior to the noble RuO_(2)(+)||Pt/C(−).This work offers valuable insights into the surface evolution and electrocatalytic mechanisms of TMSs.展开更多
Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batte...Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.展开更多
The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy densi...The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy density and cost-efficiency.However,these cathodes face critical challenges,including thermal instability and structural degradation at an elevated temperature,which hinder their practical application.This study introduces an advanced surface reconstruction strategy combining a LiScF_(4)coating,Sc/F surface co-doping,and a cation-mixing layer to address these issues.The LiScF_(4)coating serves as a durable protective barrier,reducing electrolyte decomposition,minimizing transition metal dissolution,and enhancing lithium-ion transport.Sc/F surface co-doping stabilizes lattice oxygen by increasing the energy barrier for oxygen vacancy formation and minimizing oxygen release,thereby suppressing phase transitions and interfacial side reactions.Additionally,the cation-mixing layer improves interfacial stability by alleviating lattice strain and supporting reversible cation migration,ensuring prolonged durability during cycling and under high-temperature conditions.These integrated modifications work synergistically to mitigate various degradation mechanisms,significantly improving the thermal stability,structural integrity,and electrochemical performance of Ni-rich cathodes.This approach offers a viable pathway for incorporating Ni-rich cathodes into advanced lithium-ion batteries,making them well-suited for applications requiring high thermal stability.Moreover,this research provides valuable guidance for the development of a multi-component modification strategy,paving the way for future innovations in energy storage materials and advancing high-performance battery technology.展开更多
The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding ...The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding catalyst design at the atomic scale.Here,the CoP nanowire with excellent water splitting performance and stability is used as a catalytic model to study the reconstruction process.Obvious double redox signals and valence evolution behavior of the Co site are observed,corresponding to Co^(2+)/Co^(3+)and Co^(3+)/Co4+caused by auto-oxidation process.Importantly,the in situ Raman spectrum exhibits the vibration signal of Co-OH in the non-Faradaic potential interval for oxygen evolution reaction,which is considered the initial step in reconstruction process.Density functional theory and ab initio molecular dynamics are used to elucidate this process at the atomic scale:First,OH^(-)exhibits a lower adsorption energy barrier and proton desorption energy barrier at the configuration surface,which proposes the formation of a single oxygen(-O)group.Under a higher-O group coverage,the Co-P bond is destroyed along with the POx groups.Subsequently,lower P vacancy formation energy confirm that the Ni-CoP configuration can fast transform into a highly active phase.Based on the optimized reconstruction behavior and rate-limiting barrier,the Ni-CoP nanowire exhibit an excellent overpotential of 1.59 V at 10 mA cm^(-2) for overall water splitting,which demonstrates low degradation(2.62%)during the 100 mA cm^(-2) for 100 h.This work provide systematic insights into the atomic-level reconstruction mechanism of transition metal phosphides,which benefit further design of water splitting catalysts.展开更多
Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydr...Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.展开更多
A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇...A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.展开更多
In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calcula...In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calculations. Their scanning tunneling microscopic images and work functions are simulated and compared with experimental results. In this way, the hex-H3＇ and rect-T1 models are identified as the experimental configurations for the hexagonal and rectangular types, respectively. The structural evolution mechanism of the In/Si（lll） surface with indium coverage around 1.0 monolayer is discussed. The 4×1 and -√7× √3 phases are suggested to have two different types of evolution mechanisms, consistent with experimental results.展开更多
Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electro...Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.展开更多
The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is impre...The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.展开更多
Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching...Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching strategy to tailor the electronic structure of NiMoO_(4),where the prepared NiMoO_(4) nanorods etched by H_(2)O_(2) reconstruct their surface with abundant cation deficiencies and lattice distortion.Calculation results reveal that the double cation deficiencies can make the upshift of d-band center for Ni atoms and the active sites with better oxygen adsorption capacity.As a result,the optimized sample(NMO-30M)possesses an overpotential of 260 mV at 10 mA cm−2 and excellent long-term durability of 162 h.Importantly,in situ Raman test reveals the rapid formation of high-oxidation-state transition metal hydroxide species,which can further help to improve the catalytic activity of NiMoO_(4) in OER.This work highlights the influence of surface remodification and shed some light on activating catalysts.展开更多
Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn ...Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced specific capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modification of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties.展开更多
Due to the encephalic tissues are highly irregular, three-dimensional （3D） modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction fr...Due to the encephalic tissues are highly irregular, three-dimensional （3D） modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction from magnetic reso- nance （MR） images of head, which is helpful to surgery planning and tumor localization. A heuristic algorithm is pro- posed foi＂ surface triangle mesh generation with preserved features, and the diagonal length is regarded as the heuristic information to optimize the shape of triangle. The experimental results show that our approach not only reduces the computational complexity, but also completes 3D visualization with good quality.展开更多
Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electr...Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.展开更多
Palladium-based alloy catalysts have been employed as one of the potential candidates for oxygen reduc-tion reaction(ORR),but the dissolution of transition metal hinders their application.Herein,structure or-dered PdT...Palladium-based alloy catalysts have been employed as one of the potential candidates for oxygen reduc-tion reaction(ORR),but the dissolution of transition metal hinders their application.Herein,structure or-dered PdTe intermetallic with Pd shell(o-PdTe@Pd)are synthesized via an electrochemical etching driven surface reconstruction strategy.The surface reconstruction could tune the electronic structure,weaken the adsorption energy of reaction intermediates on o-PdTe@Pd,resulting in enhanced electrocatalytic ac-tivity for ORR.The mass activity of o-PdTe@Pd is about 3.3 and 2.7 times higher than that of Pd/C in acid and alkaline,respectively.Besides,the half-potentials for ORR decay only about 44 mV and 12 mV after 30 k cycles accelerated durability test in acid and alkaline media,respectively.The enhanced dura-bility originates from the resistance of Te atoms dissolve in the ordered PdTe intermetallic core and the core-shell structure.When assembled in a Zn-air battery,o-PdTe@Pd electrode delivers a higher specific capacity(794 mAh/g)and better cycling stability than Pt/C.展开更多
Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cat...Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.展开更多
A rapid and practical method is proposed to reconstruct surface based on the linked structured light stripes which are produced by structured light projection.The subpixel points on a stripe are linked firstly one by ...A rapid and practical method is proposed to reconstruct surface based on the linked structured light stripes which are produced by structured light projection.The subpixel points on a stripe are linked firstly one by one to form a stripe ensemble which is then transformed to a point ensemble in 3D space.The initial mesh with local optimization is generated by triangulating each two adjacent point ensembles.In order to obtain a better mesh,our improved edge flipping algorithm is employed to optimize the initial mesh globally.Because of employing the information of the linked structured stripes,our reconstruction algorithm is performed fastly.Moreover,the subpixel points on each stripe are already linked on the captured images such that they do not require the high sampling density.The experiments show that the proposed method constructs a surface rapidly and effectively.展开更多
A 3D surface reconstruction method using a binocular stereo vision technology and a coded structured light,which combines a gray code with phase-shift has been studied.The accuracy of the 3 D surface reconstruction ma...A 3D surface reconstruction method using a binocular stereo vision technology and a coded structured light,which combines a gray code with phase-shift has been studied.The accuracy of the 3 D surface reconstruction mainly depends on the decoding of gray code views and phase-shift views.In order to find the boundary accurately,gray code patterns and their inverses are projected onto a human eye plaster model.The period dislocation between the gray code views and the phase-shift views in the course of decoding has been analyzed and a new method has been proposed to solve it.The splicing method is based on feature points.The result of the 3D surface reconstruction shows the accuracy and reliability of our method.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611103 and 2022YFA1403203)the Innovation Program for Quantum Science and Technology(Grant Nos.2024ZD0301300 and 2021ZD0302802)the National Natural Science Foundation of China(Grant Nos.12474128,12374133,12204008,and 12104004)。
文摘Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.
基金financially supported by National Natural Science Foundation of China(22278170,52172058)Natural Science Foundation of Anhui Province(2408085QB037)+3 种基金Natural Science Foundation of Anhui Provincial Department of Education(2023AH020042,2024AH051721)financial support from High-Level Talents Introduction and Cultivation Plan of Anhui Province-Young Top Talent,Huainan Innovation and Entrepreneurship Star Team(HNSTD-2024),Huainan Research Center of New Carbon Energy Materials(HNSPT02)New Energy Materials and Technology Research Center of Huainan Normal University.Business Finland,BATCircle2.0 project(Grant No.44612/31/2020)is acknowledged for financial supportU.L.acknowledges Finnish Research Impact Foundation for Tandem Industry Academy Professorship funding in 2023-2025.
文摘Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.
基金financially supported by the National Natural Science Foundation of China(Grant No.52073106)。
文摘Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affected by the built-in electric field of the heterostructure.In this study,P/N co-doped carbon-coated NiCo/Ni-CoO heterostructure was prepared by in situ acid etching,aniline polymerization,and pyrolysis.This method can form a tightly connected heterogeneous interface.It was found that introducing P-O bonds in the carbon shell can increase its work function,thereby enhancing the built-in electric field between the carbon shell and the core catalyst.Detailed characterizations confirm that the P-O bridge at the heterogeneous interface can provide an electron flow highway from the core to the shell.The generated carbon defects generated by P leaching during surface reconstruction also have strong electronabsorbing capacity.These effects promote the conversion of Co^(2+)to Co^(3+),thereby providing more highly active sites.The resulting catalyst shows significantly enhanced activity and stability.This study demonstrates the promoting effect of the built-in electric field on the surface reconstruction of the catalyst and emphasizes the importance of the construction of tightly connected heterogeneous interface,which is instructive for the design of excellent OER catalysts.
基金supported by the National Natural Science Foundation of China(No.22469018)the Natural Science Basic Research Program of Department of Science and Technology of Shaanxi Province(Nos.2023-JC-ZD-22 and 2023-JC-YB-404)the Scientific Research Startup Program for Introduced Talents of Shaanxi University of Technology(Nos.SLGRCQD2303 and SLGRCQD2306).
文摘Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ reconstructed and converted into high-valence metal oxyhydroxides.However,a limited understanding of the effects of electro-oxidation and anion leaching has resulted in insufficient theoretical guidance for the rational design of efficient catalysts.Herein,FeSe@NiSe nanorods were fabricated for the OER using a facile hydrothermal selenization method supported on FeNi foam.In-situ Raman spectroscopy and multiple characterization techniques were employed to elucidate the mechanism of FeSe@NiSe surface evolution.Metal cations on the catalyst surface were reconstructed and converted into OER-active species Fe/NiOOH at low potential.As the applied potential increased,electro-oxidation and leaching of Se occurred,resulting in SeO_(4)^(2−)adsorption on the catalyst surface,which further enhanced catalytic activity.As a result,the reconstructed FeSe@NiSe/iron-nickel foam(INF)exhibited exceptional catalytic activity for OER,achieving an ultralow overpotential of 283 mV at a current density of 100 mA·cm^(−2).Notably,the bifunctional FeSe@NiSe/INF electrode facilitated overall water splitting,affording a current density of 10 mA·cm^(−2) only at 1.53 V,even superior to the noble RuO_(2)(+)||Pt/C(−).This work offers valuable insights into the surface evolution and electrocatalytic mechanisms of TMSs.
基金supported by the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(NRF-2022M3H4A1A04076616 and NRF-2022M3H4A1A01008918)a cooperation project of“Basic project(referring to projects performed with the budget directly contributed by the Government to achieve the purposes of establishment of Government–funded research Institutes)”supported by the Korea Research Institute of Chemical Technology(KRICT).
文摘Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.
基金supported by the National Natural Science Foundation of China(22179008)support from the Beijing Nova Program(20230484241)+1 种基金support from the China Postdoctoral Science Foundation(2024M754084)the Postdoctoral Fellowship Program of CPSF(GZB20230931)。
文摘The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy density and cost-efficiency.However,these cathodes face critical challenges,including thermal instability and structural degradation at an elevated temperature,which hinder their practical application.This study introduces an advanced surface reconstruction strategy combining a LiScF_(4)coating,Sc/F surface co-doping,and a cation-mixing layer to address these issues.The LiScF_(4)coating serves as a durable protective barrier,reducing electrolyte decomposition,minimizing transition metal dissolution,and enhancing lithium-ion transport.Sc/F surface co-doping stabilizes lattice oxygen by increasing the energy barrier for oxygen vacancy formation and minimizing oxygen release,thereby suppressing phase transitions and interfacial side reactions.Additionally,the cation-mixing layer improves interfacial stability by alleviating lattice strain and supporting reversible cation migration,ensuring prolonged durability during cycling and under high-temperature conditions.These integrated modifications work synergistically to mitigate various degradation mechanisms,significantly improving the thermal stability,structural integrity,and electrochemical performance of Ni-rich cathodes.This approach offers a viable pathway for incorporating Ni-rich cathodes into advanced lithium-ion batteries,making them well-suited for applications requiring high thermal stability.Moreover,this research provides valuable guidance for the development of a multi-component modification strategy,paving the way for future innovations in energy storage materials and advancing high-performance battery technology.
基金the National Natural Science Foundation of China(12025503,U23B2072,12105208)the Fundamental Research Funds for the Center Universities(2042024kf0001)。
文摘The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding catalyst design at the atomic scale.Here,the CoP nanowire with excellent water splitting performance and stability is used as a catalytic model to study the reconstruction process.Obvious double redox signals and valence evolution behavior of the Co site are observed,corresponding to Co^(2+)/Co^(3+)and Co^(3+)/Co4+caused by auto-oxidation process.Importantly,the in situ Raman spectrum exhibits the vibration signal of Co-OH in the non-Faradaic potential interval for oxygen evolution reaction,which is considered the initial step in reconstruction process.Density functional theory and ab initio molecular dynamics are used to elucidate this process at the atomic scale:First,OH^(-)exhibits a lower adsorption energy barrier and proton desorption energy barrier at the configuration surface,which proposes the formation of a single oxygen(-O)group.Under a higher-O group coverage,the Co-P bond is destroyed along with the POx groups.Subsequently,lower P vacancy formation energy confirm that the Ni-CoP configuration can fast transform into a highly active phase.Based on the optimized reconstruction behavior and rate-limiting barrier,the Ni-CoP nanowire exhibit an excellent overpotential of 1.59 V at 10 mA cm^(-2) for overall water splitting,which demonstrates low degradation(2.62%)during the 100 mA cm^(-2) for 100 h.This work provide systematic insights into the atomic-level reconstruction mechanism of transition metal phosphides,which benefit further design of water splitting catalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.22162026 and 22263011)the Shaanxi Provincial Science and Technology Plan Project(No.2020JQ-792)+2 种基金the Youth Science and Technology Star Project of Shaanxi Province(No.2023KJXX-053)the Science and Technology Plan Project of Yulin Government(Nos.CXY-2022-82,CXY-2022-186,and 2023-CXY-213)the Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202310719113).
文摘Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.
文摘A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.
基金V. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20603032, No.20733004, No.21121003, No.91021004, No.20933006）, the National Key Basic Research Program （No.2011CB921400）, the Foundation of National Excellent Doctoral Dissertation of China （No.200736）, the Fundamental Research Funds for the Central Universities （No.WK2340000006 and No.WK2060140005）, and the Shanghai Supercompurer Center, the USTC-HP HPC Project, and the SCCAS.
文摘In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calculations. Their scanning tunneling microscopic images and work functions are simulated and compared with experimental results. In this way, the hex-H3＇ and rect-T1 models are identified as the experimental configurations for the hexagonal and rectangular types, respectively. The structural evolution mechanism of the In/Si（lll） surface with indium coverage around 1.0 monolayer is discussed. The 4×1 and -√7× √3 phases are suggested to have two different types of evolution mechanisms, consistent with experimental results.
文摘Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.
基金Projects(51535012,U1604255)supported by the National Natural Science Foundation of ChinaProject(2016JC2001)supported by the Key Research and Development Project of Hunan Province,China
文摘The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.
基金supported by the National Natural Science Foundation of China(No.12004146)Natural Science Foundation of Gansu Province,China(Nos.20JR5RA303 and 20JR10RA648)the Fundamental Research Funds for the Central Universities(No.LZUMMM2022007).
文摘Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching strategy to tailor the electronic structure of NiMoO_(4),where the prepared NiMoO_(4) nanorods etched by H_(2)O_(2) reconstruct their surface with abundant cation deficiencies and lattice distortion.Calculation results reveal that the double cation deficiencies can make the upshift of d-band center for Ni atoms and the active sites with better oxygen adsorption capacity.As a result,the optimized sample(NMO-30M)possesses an overpotential of 260 mV at 10 mA cm−2 and excellent long-term durability of 162 h.Importantly,in situ Raman test reveals the rapid formation of high-oxidation-state transition metal hydroxide species,which can further help to improve the catalytic activity of NiMoO_(4) in OER.This work highlights the influence of surface remodification and shed some light on activating catalysts.
基金supported by the National Key Research and Development Program of China(2022YFE0206300)the National Natural Science Foundation of China(22209047,U21A2081,22075074)+2 种基金Natural Science Foundation of Hunan Province(2020JJ5035)Hunan Provincial Department of Education Outstanding Youth Project(23B0037)Macao Science and Technology Development Fund(Macao SAR,FDCT-0096/2020/A2).
文摘Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced specific capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modification of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties.
基金supported by the National Natural Science Foundation of China(No.61202169)
文摘Due to the encephalic tissues are highly irregular, three-dimensional （3D） modeling of brain always leads to compli- cated computing. In this paper, we explore an efficient method for brain surface reconstruction from magnetic reso- nance （MR） images of head, which is helpful to surgery planning and tumor localization. A heuristic algorithm is pro- posed foi＂ surface triangle mesh generation with preserved features, and the diagonal length is regarded as the heuristic information to optimize the shape of triangle. The experimental results show that our approach not only reduces the computational complexity, but also completes 3D visualization with good quality.
基金supported by the financial support of the Guangxi Science and Technology Major Projects(Guike AA23023033)。
文摘Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts.
基金supported by the National Natural Science Foundation(No.22279036)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003).
文摘Palladium-based alloy catalysts have been employed as one of the potential candidates for oxygen reduc-tion reaction(ORR),but the dissolution of transition metal hinders their application.Herein,structure or-dered PdTe intermetallic with Pd shell(o-PdTe@Pd)are synthesized via an electrochemical etching driven surface reconstruction strategy.The surface reconstruction could tune the electronic structure,weaken the adsorption energy of reaction intermediates on o-PdTe@Pd,resulting in enhanced electrocatalytic ac-tivity for ORR.The mass activity of o-PdTe@Pd is about 3.3 and 2.7 times higher than that of Pd/C in acid and alkaline,respectively.Besides,the half-potentials for ORR decay only about 44 mV and 12 mV after 30 k cycles accelerated durability test in acid and alkaline media,respectively.The enhanced dura-bility originates from the resistance of Te atoms dissolve in the ordered PdTe intermetallic core and the core-shell structure.When assembled in a Zn-air battery,o-PdTe@Pd electrode delivers a higher specific capacity(794 mAh/g)and better cycling stability than Pt/C.
基金supported by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Officesupported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office, under Contract No. DE-SC0012704+1 种基金supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357supported by the Vehicle Technologies Office of the U.S. Department of Energy。
文摘Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.
基金the Fundamental Research Funds for the Central Universities of SCUT (No.2009ZM0235)the National Natural Science Foundation of China (No.30470488)
文摘A rapid and practical method is proposed to reconstruct surface based on the linked structured light stripes which are produced by structured light projection.The subpixel points on a stripe are linked firstly one by one to form a stripe ensemble which is then transformed to a point ensemble in 3D space.The initial mesh with local optimization is generated by triangulating each two adjacent point ensembles.In order to obtain a better mesh,our improved edge flipping algorithm is employed to optimize the initial mesh globally.Because of employing the information of the linked structured stripes,our reconstruction algorithm is performed fastly.Moreover,the subpixel points on each stripe are already linked on the captured images such that they do not require the high sampling density.The experiments show that the proposed method constructs a surface rapidly and effectively.
文摘A 3D surface reconstruction method using a binocular stereo vision technology and a coded structured light,which combines a gray code with phase-shift has been studied.The accuracy of the 3 D surface reconstruction mainly depends on the decoding of gray code views and phase-shift views.In order to find the boundary accurately,gray code patterns and their inverses are projected onto a human eye plaster model.The period dislocation between the gray code views and the phase-shift views in the course of decoding has been analyzed and a new method has been proposed to solve it.The splicing method is based on feature points.The result of the 3D surface reconstruction shows the accuracy and reliability of our method.
