Covalent organic frameworks(COFs)provide a unique platform with tunable structures allowing precise control of pore sizes,shapes and functions.The key to synthesizing COFs with desired structures is to precisely contr...Covalent organic frameworks(COFs)provide a unique platform with tunable structures allowing precise control of pore sizes,shapes and functions.The key to synthesizing COFs with desired structures is to precisely control the conformation and geometry of building blocks as well as the growth direction of COFs.To achieve this,steric effects are noteworthy that may have a significant impact on the assembly of COFs.Specifically,the introduction of sterically demanding substituents or bulky groups into monomers of COFs will lead to intramolecular conformational changes and intermolecular repulsions,which induce structural changes in COFs,including changes in torsion angles,interlayer distances,stacking modes and topologies of 2D COFs,and changes in spatial nodes,interpenetration and topologies of 3D COFs.This review will help to understand the impacts of steric effects on the structures of COFs and to take them into extensive consideration in the design and synthesis of COFs with novel functionalities and structural attributes.展开更多
This paper deals with the aeroelastic tailoring of aeronautical composite wing surfaces. The objective function is structural weight. Multi constraints, such as displacements, flutter speed and gauge requirements, are...This paper deals with the aeroelastic tailoring of aeronautical composite wing surfaces. The objective function is structural weight. Multi constraints, such as displacements, flutter speed and gauge requirements, are taken into consideration. Finite element method is used to the static analysis. Natural vibration modes are obtained by the spectral transformation Lanczos method. Subsonic doublet lattice method is used to obtain the unsteady aerodynamics.The critical flutter speed is generated by V-g method.The optimal problem is solved by the feasible direction method.The thickness of the composite wing skin is simulated by bicubic polynomials, whose coefficients combined with the cross-sectional areas or thicknesses of other finite elements are the design variables. The scale of the problem is reduced by variable linkage. Derivative analysis is performed analytically.Two composite wing boxes and a swept-back composite wing are optimized at the end of the paper.展开更多
Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization ...Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization enhancement in-depth mechanism are top priorities.Herein,we introduce the intergrowth ferroelectrics Bi_(7)Ti_(4)NbO_(21)thin-layer nanosheets for piezo-photocatalytic CO_(2)reduction.Density functional theory(DFT)calculations indicate that interlayer lattice mismatch leads to increased tilting and rotation angle of Ti/NbO_(6)octahedra on perovskite-like layers,serving as the main reason for increased polarization.Furthermore,the tilting and rotation angle of the interlayer octahedron further increase under stress,suggesting a stronger driving force generated to facilitate charge carrier separation efficiency.Meanwhile,Bi_(7)Ti_(4)NbO_(21)nanosheets provide abundant active sites to effectively adsorb CO_(2)and acquire sensitive stress response,thereby presenting synergistically advanced piezo-photocatalytic CO_(2)reduction activity with a high CO generation rate of 426.97μmol g^(-1)h^(-1).Our work offers new perspectives and directions for initiating and investigating the mechanisms of high-performance intergrowth piezo-photocatalysts.展开更多
The typical method for preparing the porous carbon used in supercapacitors(SCs)is time-consuming and energy-intensive.We report a fast and efficient route to synthesize and tailor the structure of porous carbon by a J...The typical method for preparing the porous carbon used in supercapacitors(SCs)is time-consuming and energy-intensive.We report a fast and efficient route to synthesize and tailor the structure of porous carbon by a Joule heating technique(JHT)using phenolic resin and precursors.During the JHT process,the time and energy needed are both significantly reduced because the precursor is heated to the target temperature at a rate of 1100 K/s,so the porous carbon is formed with the release of small molecules and the etching of the substrate by K_(2)CO_(3).JHT has a higher energy efficiency than traditional carbonization methods in a tube furnace and allows for precise control of the pyrolysis process,thus achieving better control of the material’s structure and properties.Samples obtained by JHT contain abundant pores and a large specific surface area(1652.7 m^(2)/g),which give an excellent specific capacitance of 476.0 F/g and rate capability(75.1%capacitance retention at 64.0 A/g in an aqueous alkaline electrolyte).Furthermore,in electrolytes of 17.0 mol/kg NaClO_(4)(water-in-salt)and 1.0 mol/L TEABF4/AN,the symmetric SCs have a maximum energy density of 33.3 and 50.8 Wh/kg at power densities of 220.4 and 376.4 W/kg,respectively.The cells also have good long-term stability,with a nearly 100%Coulombic efficiency,and a capacitance retention of 93.1%in a water-in-salt electrolyte after 10000 cycles,and 88.9%in an organic electrolyte after 8000 cycles.This study shows that JHT has the potential to serve as an ultra-fast method to prepare porous carbons for energy storage.展开更多
Crystal facet engineering is an important strategy for fine-tuning the physical and chemical properties in many fields,which will provide an effective route to fundamentally understand the relationship between the sur...Crystal facet engineering is an important strategy for fine-tuning the physical and chemical properties in many fields,which will provide an effective route to fundamentally understand the relationship between the surface structure and the electron state.Many researchers have worked on the technological performance improvement of noble metal nanoparticles and simple metal oxides by tailoring their crystal facets.Perovskite structure oxides are the most prominent mixed-oxide materials in the field of heterogeneous catalysis due to the acceptable catalytic activity and thermal stability.However,the utilization of perovskite oxides is still limited in comparison with noble metal catalysts because the most stable surface is usually terminated with non-catalytically active crystal facets.High-index facet tailoring may be an effective route to improve the activity of perovskite structure catalysts.So far,only several perovskite oxides have been reported on the crystal facet tailoring with well-defined polyhedral shapes.Herein,we review the recent progress in the facet tailoring arts in perovskite structure oxides.This review begins with a general introduction to facet related physical and chemical behavior and the potential facet-dependent applications.Then,the general principles of crystal growth and facet tailoring will be discussed.The principle for possible grown facets of perovskite structure oxides will be proposed.Various shape growth and facet tailoring of perovskite structure oxides will be reviewed in four parts:(i)tungsten and molybdenum trioxide(A^(0)B+6O_(3));(ii)niobate and tantalite(A^(+1)B^(+5)O_(3));(iii)titanate and zirconate(A^(+2)B^(+4)O_(3));(iv)ferrite,chromite and manganite(A^(+3)B^(+3)O_(3)),including mixed-valence state perovskite compounds.The facet tailoring mechanism in perovskite oxides will be discussed in the next section.Finally,an overview of the promising future of facet dependent applications will be given as a perspective outlook.Fundamental understanding of facet tailoring is expected to open up strategies for the development of highly efficient perovskite oxide materials.展开更多
Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behav...Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behavior.Binary MX2 layers with different metal and/or chalcogen elements have similar structural parameters but varied optoelectronic properties,providing opportunities for atomically substitutional engineering via partial alteration of metal or/and chalcogenide atoms to produce ternary or quaternary TMDs.The resulting multinary TMD layers still maintain structural integrity and homogeneity while achieving tunable(opto)electronic properties across a full range of composition with arbitrary ratios of introduced metal or chalcogen to original counterparts(0–100%).Atomic substitution in TMD layers offers new adjustable degrees of freedom for tailoring crystal phase,band alignment/structure,carrier density,and surface reactive activity,enabling novel and promising applications.This review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior applications.The emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential applications.Finally,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field.展开更多
In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（O...In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（Oxa^（2-）） and rare earth ions（RE^（3＋）） in the range of 0.5：1.1：1.2：1, 5：1. and 10：1. The obtained results show that the crystallinity, particle size and upconversion luminescence intensity of the as-synthesized NYFEY particles are gradually decreased as the Oxa^（2-）：RE^（3＋） molar ratio increases from 0.5：1 to 10：1. For the purpose of photoelectrochemical performance evaluation,the as-synthesized NYFEY particles with different morphologies are incorporated into the nanocrystalline TiO2 films to form the multifunctional nano-and sub-micro meter composite photoanodes of dye-sensitized solar cells（DSSCs）. A short-circuit current density（Jsc） of 14.26 mA/cm^2 and power conversion efficiency（PCE） of 7.31% are obtained for DSSCs prepared with hexagonal rod-like NYFEY crystals,evidencing an increase of 29.8% compared with DSSCs prepared with only TiO_2 nanoparticles. The demonstrated synthesis approach for tailoring the morphology and size of NYFEY particles and enhancing the performance of DSSCs can also be applied for other types of solar cells.展开更多
Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices...Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED),plant cultivation LED,and temperature thermometer.Up to now,Mn^(4+)has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors.However,how to correlate the structure-activity relationship between host framework,luminescence property,and photoelectric device is urgently demanded.In this review,we thoroughly summarize the recent advances of Mn^(4+)doped phosphors.Meanwhile,several strategies like co-doping and defect passivation for improving Mn^(4+)emission are also discussed.Most importantly,the relationship between the protocols for tailoring the structures of Mn^(4+)doped phosphors,increased luminescence performance,and the targeted devices with efficient photoelectric and energy conversion efficiency is deeply correlated.Finally,the challenges and perspectives of Mn^(4+)doped phosphors for practical applications are anticipated.We cordially anticipate that this review can deliver a deep comprehension of not only Mn^(4+)luminescence mechanism but also the crystal structure tailoring strategy of phosphors,so as to spur innovative thoughts in designing advanced phosphors and deepening the applications.展开更多
Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries.Compared with platinum,palladium holds a stronger oxygen ...Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries.Compared with platinum,palladium holds a stronger oxygen affinity and high abundance on earth,endowing it a promising alternative to platinum in anion-exchange membrane fuel cells.However,the sluggish oxygen reduction reaction of palladium still remains a great issue and requires the design of stable and efficient palladium-based electrocatalysts.Here,we report the solvothermal/hydrothermal reduction method to prepare a series of PdAg_(x)nanowires.The prepared PdAg_(x)NWs exhibit hollow structure,which greatly improves the utilization of Pd atoms,offering an outstanding ORR performance.Specifically,PdAg_(2)NWs exhibit an onset potential of 0.92 V and mass activity of 350.7 mA mgPd^(-1)at 0.7 V vs.RHE for ORR in 0.1 M KOH solution.This work provides a novel approach for the construction of hollow NWs and their subsequent applications in other electrocatalytic reactions.展开更多
Precisely tailoring the structure of bimetal nanoclusters(NCs)at the atomic level has been proven to be an effective way to tune their physicochemical properties;however,achieving this remains challenging.Herein,the r...Precisely tailoring the structure of bimetal nanoclusters(NCs)at the atomic level has been proven to be an effective way to tune their physicochemical properties;however,achieving this remains challenging.Herein,the regulation from the reported Ag_(26)Pt(2-EBT)_(18)(PPh_(3))_(6)(Ag_(26)Pt)to Ag_(16)Pt(2-EBT)_(6)(dppm)_(4)Cl_(2)(Ag_(16)Pt;2-EBTH=2-ethylbenzenethiol;dppm=bis-(diphenylphosphino)methane)NC was instantaneously(within one minute)realized through an asymmetrical pseudo-ligand exchange strategy.Single crystal X-ray crystallography(SCXC)combined with X-ray photoelectron spectroscopy(XPS)and thermogravimetric analysis(TGA)confirmed its composition and structure.The target Ag_(16)Pt NC consists of a Pt@Ag_(12) icosahedral core capped by a ligand shell of a pair of dimetric-SR-Ag-SR-Ag-SR-staple motifs,four dppm ligands,and two chlorine atoms.Their geometrical,electronic and crystallographical structures were comparatively investigated before and after regulation,which also provides some clues for understanding the blueshift of the emission center(Ag_(26)Pt:845 nm vs.Ag_(16)Pt:675 nm).This work provides important insights into the regulation of structures and photoluminescence of bimetal NCs protected by co-ligands.展开更多
Twisted two-dimensional van der Waals heterostructures provide a fertile ground for tailoring electronic and structural properties.However,their vast configurational space poses challenges for systematic study.Here,we...Twisted two-dimensional van der Waals heterostructures provide a fertile ground for tailoring electronic and structural properties.However,their vast configurational space poses challenges for systematic study.Here,weintroduce SAMBA,an open-source,high-throughput Python workflowthat automates the generation,simulation,and analysis of twisted bilayers.Using the coincidence lattice method,we generate a comprehensive set of over 18,000 quasi-commensurable homo-and heterobilayer structures based on 63 experimentally reported monolayers,and perform DFT simulations on a growing subset.The resulting database includes symmetry,interlayer energetics,band alignment,and charge transfer.A detailed case study on graphene-jacutingaite illustrates the framework’s capabilities.This platform offers a robust foundation for data-driven discovery and the rational design of 2D materials with tunable properties.展开更多
The propagation of surface acoustic waves(SAWs) in two-dimensional phononic crystals(PnCs) with and without coupling-enhancement slabs was theoretically investigated using a three-dimensional finite element method.Dif...The propagation of surface acoustic waves(SAWs) in two-dimensional phononic crystals(PnCs) with and without coupling-enhancement slabs was theoretically investigated using a three-dimensional finite element method.Different piezoelectric substrates,for example,lithium niobate(LiNbO_3),gallium nitride(GaN),and aluminium nitride(A1N),were taken into account.Compared to the PnCs without coupling-enhancement slabs,the coupling between each pillar and its nearest neighbor was largely enhanced in the presence of slabs.The bandwidth of the first directional band gap increased markedly compared with its initial value for the PnCs without a slab(within square symmetry).In addition,with increasing thicknesses of the slabs bonded between neighboring pillars,the first directional band-gap and second directional band gap of the PnCs tend to merge.Therefore,the structure with coupling-enhancement slabs can be used as an excellent electrical band elimination filter for most electro-SAW devices,offering a new strategy to realize chip-scale applications in electroacoustic signal processing,optoacoustic modulation,and even SAW microfluidic devices.展开更多
基金supported by the National Natural Science Foundation of China(22225503,U21A20285,21975188,22105149)the support by the fellowship of China National Postdoctoral Program for Innovative Talents(BX2021226)。
文摘Covalent organic frameworks(COFs)provide a unique platform with tunable structures allowing precise control of pore sizes,shapes and functions.The key to synthesizing COFs with desired structures is to precisely control the conformation and geometry of building blocks as well as the growth direction of COFs.To achieve this,steric effects are noteworthy that may have a significant impact on the assembly of COFs.Specifically,the introduction of sterically demanding substituents or bulky groups into monomers of COFs will lead to intramolecular conformational changes and intermolecular repulsions,which induce structural changes in COFs,including changes in torsion angles,interlayer distances,stacking modes and topologies of 2D COFs,and changes in spatial nodes,interpenetration and topologies of 3D COFs.This review will help to understand the impacts of steric effects on the structures of COFs and to take them into extensive consideration in the design and synthesis of COFs with novel functionalities and structural attributes.
文摘This paper deals with the aeroelastic tailoring of aeronautical composite wing surfaces. The objective function is structural weight. Multi constraints, such as displacements, flutter speed and gauge requirements, are taken into consideration. Finite element method is used to the static analysis. Natural vibration modes are obtained by the spectral transformation Lanczos method. Subsonic doublet lattice method is used to obtain the unsteady aerodynamics.The critical flutter speed is generated by V-g method.The optimal problem is solved by the feasible direction method.The thickness of the composite wing skin is simulated by bicubic polynomials, whose coefficients combined with the cross-sectional areas or thicknesses of other finite elements are the design variables. The scale of the problem is reduced by variable linkage. Derivative analysis is performed analytically.Two composite wing boxes and a swept-back composite wing are optimized at the end of the paper.
基金support from the Natural Science Foundation of Jiangsu Province(BK20220596)Innovative science and technology platform project of cooperation between Yangzhou City and Yangzhou University,China(No.YZ202026305)+1 种基金Natural Science Foundation of China(21922202,21673202 and 22272147)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization enhancement in-depth mechanism are top priorities.Herein,we introduce the intergrowth ferroelectrics Bi_(7)Ti_(4)NbO_(21)thin-layer nanosheets for piezo-photocatalytic CO_(2)reduction.Density functional theory(DFT)calculations indicate that interlayer lattice mismatch leads to increased tilting and rotation angle of Ti/NbO_(6)octahedra on perovskite-like layers,serving as the main reason for increased polarization.Furthermore,the tilting and rotation angle of the interlayer octahedron further increase under stress,suggesting a stronger driving force generated to facilitate charge carrier separation efficiency.Meanwhile,Bi_(7)Ti_(4)NbO_(21)nanosheets provide abundant active sites to effectively adsorb CO_(2)and acquire sensitive stress response,thereby presenting synergistically advanced piezo-photocatalytic CO_(2)reduction activity with a high CO generation rate of 426.97μmol g^(-1)h^(-1).Our work offers new perspectives and directions for initiating and investigating the mechanisms of high-performance intergrowth piezo-photocatalysts.
文摘The typical method for preparing the porous carbon used in supercapacitors(SCs)is time-consuming and energy-intensive.We report a fast and efficient route to synthesize and tailor the structure of porous carbon by a Joule heating technique(JHT)using phenolic resin and precursors.During the JHT process,the time and energy needed are both significantly reduced because the precursor is heated to the target temperature at a rate of 1100 K/s,so the porous carbon is formed with the release of small molecules and the etching of the substrate by K_(2)CO_(3).JHT has a higher energy efficiency than traditional carbonization methods in a tube furnace and allows for precise control of the pyrolysis process,thus achieving better control of the material’s structure and properties.Samples obtained by JHT contain abundant pores and a large specific surface area(1652.7 m^(2)/g),which give an excellent specific capacitance of 476.0 F/g and rate capability(75.1%capacitance retention at 64.0 A/g in an aqueous alkaline electrolyte).Furthermore,in electrolytes of 17.0 mol/kg NaClO_(4)(water-in-salt)and 1.0 mol/L TEABF4/AN,the symmetric SCs have a maximum energy density of 33.3 and 50.8 Wh/kg at power densities of 220.4 and 376.4 W/kg,respectively.The cells also have good long-term stability,with a nearly 100%Coulombic efficiency,and a capacitance retention of 93.1%in a water-in-salt electrolyte after 10000 cycles,and 88.9%in an organic electrolyte after 8000 cycles.This study shows that JHT has the potential to serve as an ultra-fast method to prepare porous carbons for energy storage.
基金supported by the National Natural Science Foundation of China(grants 90922034,21131002,and 21201075)the Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP grant 20110061130005).
文摘Crystal facet engineering is an important strategy for fine-tuning the physical and chemical properties in many fields,which will provide an effective route to fundamentally understand the relationship between the surface structure and the electron state.Many researchers have worked on the technological performance improvement of noble metal nanoparticles and simple metal oxides by tailoring their crystal facets.Perovskite structure oxides are the most prominent mixed-oxide materials in the field of heterogeneous catalysis due to the acceptable catalytic activity and thermal stability.However,the utilization of perovskite oxides is still limited in comparison with noble metal catalysts because the most stable surface is usually terminated with non-catalytically active crystal facets.High-index facet tailoring may be an effective route to improve the activity of perovskite structure catalysts.So far,only several perovskite oxides have been reported on the crystal facet tailoring with well-defined polyhedral shapes.Herein,we review the recent progress in the facet tailoring arts in perovskite structure oxides.This review begins with a general introduction to facet related physical and chemical behavior and the potential facet-dependent applications.Then,the general principles of crystal growth and facet tailoring will be discussed.The principle for possible grown facets of perovskite structure oxides will be proposed.Various shape growth and facet tailoring of perovskite structure oxides will be reviewed in four parts:(i)tungsten and molybdenum trioxide(A^(0)B+6O_(3));(ii)niobate and tantalite(A^(+1)B^(+5)O_(3));(iii)titanate and zirconate(A^(+2)B^(+4)O_(3));(iv)ferrite,chromite and manganite(A^(+3)B^(+3)O_(3)),including mixed-valence state perovskite compounds.The facet tailoring mechanism in perovskite oxides will be discussed in the next section.Finally,an overview of the promising future of facet dependent applications will be given as a perspective outlook.Fundamental understanding of facet tailoring is expected to open up strategies for the development of highly efficient perovskite oxide materials.
基金This work was supported by National Key R&D Program of China(2021YFF1200200)Peiyang Talents Project of Tianjin University.
文摘Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behavior.Binary MX2 layers with different metal and/or chalcogen elements have similar structural parameters but varied optoelectronic properties,providing opportunities for atomically substitutional engineering via partial alteration of metal or/and chalcogenide atoms to produce ternary or quaternary TMDs.The resulting multinary TMD layers still maintain structural integrity and homogeneity while achieving tunable(opto)electronic properties across a full range of composition with arbitrary ratios of introduced metal or chalcogen to original counterparts(0–100%).Atomic substitution in TMD layers offers new adjustable degrees of freedom for tailoring crystal phase,band alignment/structure,carrier density,and surface reactive activity,enabling novel and promising applications.This review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior applications.The emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential applications.Finally,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field.
基金Project partially supported by the National Natural Science Foundation of China(51202179)the National Science and Technology Research Key Project of the Ministry of Education(212174)+1 种基金the Natural Science Foundation of Shaanxi Province(2013KJXX-57)the Science Foundation of Shaanxi Provincial Department of Education(12JS060,13JS053,14JS047,14JS048,16JS058)
文摘In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（Oxa^（2-）） and rare earth ions（RE^（3＋）） in the range of 0.5：1.1：1.2：1, 5：1. and 10：1. The obtained results show that the crystallinity, particle size and upconversion luminescence intensity of the as-synthesized NYFEY particles are gradually decreased as the Oxa^（2-）：RE^（3＋） molar ratio increases from 0.5：1 to 10：1. For the purpose of photoelectrochemical performance evaluation,the as-synthesized NYFEY particles with different morphologies are incorporated into the nanocrystalline TiO2 films to form the multifunctional nano-and sub-micro meter composite photoanodes of dye-sensitized solar cells（DSSCs）. A short-circuit current density（Jsc） of 14.26 mA/cm^2 and power conversion efficiency（PCE） of 7.31% are obtained for DSSCs prepared with hexagonal rod-like NYFEY crystals,evidencing an increase of 29.8% compared with DSSCs prepared with only TiO_2 nanoparticles. The demonstrated synthesis approach for tailoring the morphology and size of NYFEY particles and enhancing the performance of DSSCs can also be applied for other types of solar cells.
基金financially supported by the National Natural Science Foundation of China(52072101,51972088,U20A20122 and U1663225)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R52)of the Chinese Ministry of Education+2 种基金the Program of Introducing Talents of Discipline to Universities-Plan 111(Grant No.B20002)from the Ministry of Science and Technology and the Ministry of Education of ChinaHubei Provincial Department of Education for the“Chutian Scholar”programsupported by the European Commission Interreg V FranceWallonie-Vlaanderen project“Depollut Air”。
文摘Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED),plant cultivation LED,and temperature thermometer.Up to now,Mn^(4+)has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors.However,how to correlate the structure-activity relationship between host framework,luminescence property,and photoelectric device is urgently demanded.In this review,we thoroughly summarize the recent advances of Mn^(4+)doped phosphors.Meanwhile,several strategies like co-doping and defect passivation for improving Mn^(4+)emission are also discussed.Most importantly,the relationship between the protocols for tailoring the structures of Mn^(4+)doped phosphors,increased luminescence performance,and the targeted devices with efficient photoelectric and energy conversion efficiency is deeply correlated.Finally,the challenges and perspectives of Mn^(4+)doped phosphors for practical applications are anticipated.We cordially anticipate that this review can deliver a deep comprehension of not only Mn^(4+)luminescence mechanism but also the crystal structure tailoring strategy of phosphors,so as to spur innovative thoughts in designing advanced phosphors and deepening the applications.
基金supported by the National Natural Science Foundation of China(22162006,22102035)Natural Science Foundation of Guangxi Province(2019GXNSFGA245003,2021GXNSFBA220077).
文摘Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries.Compared with platinum,palladium holds a stronger oxygen affinity and high abundance on earth,endowing it a promising alternative to platinum in anion-exchange membrane fuel cells.However,the sluggish oxygen reduction reaction of palladium still remains a great issue and requires the design of stable and efficient palladium-based electrocatalysts.Here,we report the solvothermal/hydrothermal reduction method to prepare a series of PdAg_(x)nanowires.The prepared PdAg_(x)NWs exhibit hollow structure,which greatly improves the utilization of Pd atoms,offering an outstanding ORR performance.Specifically,PdAg_(2)NWs exhibit an onset potential of 0.92 V and mass activity of 350.7 mA mgPd^(-1)at 0.7 V vs.RHE for ORR in 0.1 M KOH solution.This work provides a novel approach for the construction of hollow NWs and their subsequent applications in other electrocatalytic reactions.
基金supported by the National Natural Science Foundation of China(22201225,22371108 and 21971246)Taishan Scholar Foundation of Shandong Province(tsqn202211242)and the Chunhui Program of the Ministry of Education of China(HZKY20220463)+5 种基金China Postdoctoral Science Foundation(2023M733539)XiangJiang Scholars Scheme Program(XJ2023006)Postdoctoral Researcher Scientific Activity Funding Project in Anhui Province(2023A660)Scientific Program Funded by the Shaanxi Provincial Education Department(23JK0456)Scientific and Technological Plan Project of Xi’an Beilin District(GX2310)Scientific and Technological Plan Project of Xi’an Science and Technology Bureau(24GXFW0017).
文摘Precisely tailoring the structure of bimetal nanoclusters(NCs)at the atomic level has been proven to be an effective way to tune their physicochemical properties;however,achieving this remains challenging.Herein,the regulation from the reported Ag_(26)Pt(2-EBT)_(18)(PPh_(3))_(6)(Ag_(26)Pt)to Ag_(16)Pt(2-EBT)_(6)(dppm)_(4)Cl_(2)(Ag_(16)Pt;2-EBTH=2-ethylbenzenethiol;dppm=bis-(diphenylphosphino)methane)NC was instantaneously(within one minute)realized through an asymmetrical pseudo-ligand exchange strategy.Single crystal X-ray crystallography(SCXC)combined with X-ray photoelectron spectroscopy(XPS)and thermogravimetric analysis(TGA)confirmed its composition and structure.The target Ag_(16)Pt NC consists of a Pt@Ag_(12) icosahedral core capped by a ligand shell of a pair of dimetric-SR-Ag-SR-Ag-SR-staple motifs,four dppm ligands,and two chlorine atoms.Their geometrical,electronic and crystallographical structures were comparatively investigated before and after regulation,which also provides some clues for understanding the blueshift of the emission center(Ag_(26)Pt:845 nm vs.Ag_(16)Pt:675 nm).This work provides important insights into the regulation of structures and photoluminescence of bimetal NCs protected by co-ligands.
基金support from the Brazilian agencies FAPESP (grants 23/12336-5, 23/09820-2 and FAPESP-CEPID 24/00989-7)CNPq (INCT - Materials Informatics) grant 157793/2025-7, and LNCC (Laboratório Nacional de Computação Científica) for computer time (Project didmat).
文摘Twisted two-dimensional van der Waals heterostructures provide a fertile ground for tailoring electronic and structural properties.However,their vast configurational space poses challenges for systematic study.Here,weintroduce SAMBA,an open-source,high-throughput Python workflowthat automates the generation,simulation,and analysis of twisted bilayers.Using the coincidence lattice method,we generate a comprehensive set of over 18,000 quasi-commensurable homo-and heterobilayer structures based on 63 experimentally reported monolayers,and perform DFT simulations on a growing subset.The resulting database includes symmetry,interlayer energetics,band alignment,and charge transfer.A detailed case study on graphene-jacutingaite illustrates the framework’s capabilities.This platform offers a robust foundation for data-driven discovery and the rational design of 2D materials with tunable properties.
基金supported by the National Basic Research Program of China (GrantNos.2013CB632904,and 2013CB63 2702)the National Nature Science Foundation of China(Grant Nos.11134006,11625418,11474158,and 51472114)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20140019)the project funded by the Priority Academic Program Development of Jiangsu Higher Education
文摘The propagation of surface acoustic waves(SAWs) in two-dimensional phononic crystals(PnCs) with and without coupling-enhancement slabs was theoretically investigated using a three-dimensional finite element method.Different piezoelectric substrates,for example,lithium niobate(LiNbO_3),gallium nitride(GaN),and aluminium nitride(A1N),were taken into account.Compared to the PnCs without coupling-enhancement slabs,the coupling between each pillar and its nearest neighbor was largely enhanced in the presence of slabs.The bandwidth of the first directional band gap increased markedly compared with its initial value for the PnCs without a slab(within square symmetry).In addition,with increasing thicknesses of the slabs bonded between neighboring pillars,the first directional band-gap and second directional band gap of the PnCs tend to merge.Therefore,the structure with coupling-enhancement slabs can be used as an excellent electrical band elimination filter for most electro-SAW devices,offering a new strategy to realize chip-scale applications in electroacoustic signal processing,optoacoustic modulation,and even SAW microfluidic devices.
