Metal-organic frameworks(MOFs)have potential application prospects in the electrochemical energy storage and conversion area on account of their high specific surface area,high porosity,tunable pore size,and structura...Metal-organic frameworks(MOFs)have potential application prospects in the electrochemical energy storage and conversion area on account of their high specific surface area,high porosity,tunable pore size,and structural diversity when compared to traditional porous materials.In order to expand the application scope of MOFs,thermal decomposition can be carried out via calcination treatment in order to convert them into porous metal oxide materials.In this review,we summarize the synthetic methods of MOF-derived transition metal oxide(TMO)composites and their applications in lithium-ion batteries(LIBs)as anodes.A variety of TMOs and composites with different structures and morphologies derived from MOFs based on several types of ligands,including 1,4-benzenedicarboxylic acid(H_(2)BDC),1,3,5-benzenetricarboxylic acid(H_(3)BTC),2-methylimidazole,ferricyanide,and other unusual organic linkers,have been discussed.Finally,current challenges and possible solutions of MOF-derived anode materials have been proposed.展开更多
Manganese dioxide(MnO_(2)),a type of redox-active transition-metal dioxide,has found wide applications in catalysts,oxidants,ferrites,achromats and battery materials.In addition,MnO_(2) is also increasingly being used...Manganese dioxide(MnO_(2)),a type of redox-active transition-metal dioxide,has found wide applications in catalysts,oxidants,ferrites,achromats and battery materials.In addition,MnO_(2) is also increasingly being used in the biomedical field for disease diagnosis and treatment.Despite its great potential,there are limited articles that comprehensively review the use of MnO_(2) in disease diagnosis and treatment.This review provides a concise overview of the latest developments in MnO_(2) nanomaterials,focusing on their applications as magnetic resonance,photoacoustic and fluorescent contrast agents.We first summarize the preparation methods of MnO_(2) nanomaterials and the mechanisms by which they serve as magnetic resonance contrast agents.We then briefly introduce their applications as photoacoustic and fluorescent contrast agents.Finally,we provide an overview of the therapeutic applications of MnO_(2) nanomaterials and discuss the challenges and prospects for their future clinical applications.展开更多
Ferroelectric materials have broad application prospects in photovoltaics,energy storage,information storage and other fields;however,obtaining ferroelectric materials through rational molecular design remains a chall...Ferroelectric materials have broad application prospects in photovoltaics,energy storage,information storage and other fields;however,obtaining ferroelectric materials through rational molecular design remains a challenge.Noncentrosymmetric crystallization,directional arrangement of dipoles and an appropriate flipping barrier are all key difficulties in constructing ideal ferroelectric materials.In this article,a novel hybrid material,TDMHACdCl_(3)(1,where TDMHA^(+)is N-(tert-butyl)-N,N-dimethylhydroxylammonium),exhibiting ferroelectric properties was successfully synthesized and characterized.A CH_(3)/OH substitution strategy was employed to form a hydrogen bond between the organic cation and the inorganic framework,deflecting the dipole moment direction of the cation.To minimize the energy of the crystal lattice,hydrogen bonds compete with the cation conformation,causing the cations to deviate from the optimal conformation and allowing the dipoles to be oriented in one direction.The crystal structure and quantum chemical calculations are thoroughly discussed to reveal the origin of the ferroelectric property in this work.We believe that our design strategy will contribute to the discovery of more ferroelectric materials.展开更多
Aqueous sodium-ion batteries(ASIBs)promise particularly increased operational safety and lower manufacturing cost than the current state-of-the-art organic electrolyte-based lithium-ion batteries.However,the output vo...Aqueous sodium-ion batteries(ASIBs)promise particularly increased operational safety and lower manufacturing cost than the current state-of-the-art organic electrolyte-based lithium-ion batteries.However,the output voltages of reported ASIBs are still restricted to under 1.5 V due to the generally high redox potentials of currently reported anode materials.In this work,we innovatively selected FeSe_(2)as the anode material for an ASIB to obtain a high output voltage.展开更多
The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials....The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials.In recent times,there has been a continuous emergence of diverse halide systems.This study provides a comprehensive review of the synthesis strategies classification schemes,structural attributes,ion transport mechanisms,and modified means of halides.Notably,the paper delves into a detailed analysis of the structural details and ion conduction mechanisms of several representative halides.Furthermore,this review also examines the intrinsic connection between the recently discovered oxyhalides and halides and figures out the primary obstacles and prospective directions for advancement through a thorough review and analysis.展开更多
Thermoelectrics is a research area that focuses on the development of high-performance materials for direct thermal and electrical energy conversion in power generation and solid-state cooling.Ever since Ioffe’s infe...Thermoelectrics is a research area that focuses on the development of high-performance materials for direct thermal and electrical energy conversion in power generation and solid-state cooling.Ever since Ioffe’s inference in 1950s that heavily doped semiconductors make the best thermoelectrics,inorganic semiconductors and semimetals have remained the cornerstone of high-performance thermoelectric materials.In this article,we review the recent advances in inorganic material thermoelectrics with special emphases on:(i)the complementary local-global view of material and the roles of configurational entropy and Fermi surface complexity in material screening;(ii)the emerging schemes of resonant bonding,dynamic disorder,“gap”engineering,pudding-mold-shaped bands in material performance enhancement;(iii)a list of promising bulk materials,such as host-vip structures,half-Heusler compounds,silicides,Zintl phases,and incommensurate structures;and(iv)state-of-the-art materials synthesis and fabrication techniques.These advances will facilitate the development of next-generation bulk thermoelectric materials.展开更多
Surface modification is a simple and efficient method to enhance the gas sensing properties of semiconductor materials.In this paper,Fe_(2)O_(3)nanoparticle-decorated ZnO nanorods are successfully fabricated by a faci...Surface modification is a simple and efficient method to enhance the gas sensing properties of semiconductor materials.In this paper,Fe_(2)O_(3)nanoparticle-decorated ZnO nanorods are successfully fabricated by a facile two-step synthesis method.The SEM,TEM and XPS results indicate that the Fe_(2)O_(3)nanoparticles grow directly on the surface of ZnO nanorods.The gas sensing properties of pure ZnO and Fe_(2)O_(3)/ZnO nanocomposites have been systematically analyzed.The gas response value of a 1 wt%Fe_(2)O_(3)/ZnO sample is 14.5 to 100 ppm triethylamine(TEA)at the optimal operating temperature of 260℃,which is about 3 times that of pure ZnO(5.0).In addition,the 1 wt%Fe_(2)O_(3)/ZnO sensor reflects a rapid response/recovery time(1 s/14 s).The density functional theory(DFT)simulation results confirm that after the Fe_(2)O_(3)cluster modifies the surface of ZnO,the atomic position at the interface changes significantly and the structure of Fe_(2)O_(3)/ZnO has the lowest adsorption energy for TEA molecules;these are the key factors for improving the gas sensitivity of the composite sample.展开更多
Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,...Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,-2)ligands,which contain a rigid asymmetric four-membered Ir-N-C-S chelating ring.The reaction of iridium complex precursors(2a and 2b)with an equal amount of the four-membered ring S^N ligand at a low temperature produces the kinetic isomers Ir1K and Ir2K,while a higher temperature leads to the formation of their corresponding thermodynamic isomers Ir1T and Ir2T.The X-ray diffraction analysis shows that the kinetic isomers exhibit a trans-S^N configuration,which is in contrast with the trans-N^N configuration of the thermodynamic isomers,and their coordination bond lengths,bond angles and packing patterns are also quite different.More importantly,all isomers showed efficient deepred emission(619-676 nm),and the thermodynamic isomers have shorter emission wavelengths,longer excited state lifetimes and higher luminescent efficiencies than their corresponding kinetic isomers.Theoretical calculations show that the four-membered ring S^N ligand in the thermodynamic isomers is more involved in the excited state than that in the kinetic isomers,and the^(3)MLCT effects are more pronounced in the thermodynamic isomers.Notably,OLED devices incorporating both thermodynamic and kinetic isomers(Ir2T and Ir2K)as emitting layers can achieve good maximum external quantum efficiencies(EQEs)(5.0%and 4.6%)peaking at 642 nm and 643 nm of the deep-red region with CIE coordinates(0.675,0.323)and(0.668,0.329),respectively,accompanied by a low turn-on voltage(3.0 V).This study provides an important strategy for the design of deep-red emitting geometric isomers of iridium complexes and their photoelectric applications.展开更多
Inorganic compounds with fluorite-related structures are among the well-known multifunctional materials.In this work,Y_(10)Ta_(4)O_(25):Eu^(3+)with a fluorite-related structure was prepared using the ceramic synthesis...Inorganic compounds with fluorite-related structures are among the well-known multifunctional materials.In this work,Y_(10)Ta_(4)O_(25):Eu^(3+)with a fluorite-related structure was prepared using the ceramic synthesis method.XRD patterns and Rietveld refinements were used to verify the phase formation with an orthorhombic space group of Cmmm(65).The relationship between the luminescence properties and structural characteristics was studied in detail.Compared with earlier reported phosphors,Y_(10)Ta_(4)O_(25):Eu^(3+)exhibits peculiar luminescence characteristics.The transition peaks from ^(5)D_(0) to ^(7)F_(1),^(7)F_(2),and ^(7)F_(4)(570-720 nm)all showed fairly strong intensities,and emission transitions from the high excited states ^(5)D_(1,2,3) were detected at room temperature,etc.The experiments confirmed that the peculiar luminescence of Y_(10)Ta_(4)O_(25):Eu^(3+)is due to its distinctive structure,such as the strong covalent nature and high polarizability of the(Y/Eu)O8 polyhedron in the lattice.The doping mechanism was investigated using the spectroscopy probe of Eu^(3+)by laser site-selective excitation and emission in the ^(5)D_(0)→^(7)F0 region.Eu^(3+)ions mostly tend to preferentially occupy the Y1 sites first,which show shorter bond lengths and significant electronic repulsion in the(Y/Eu)O8 polyhedron.The phosphor exhibited a high quantum efficiency of 45% and good thermal stability.Some light-emitting diode lighting devices were fabricated by encapsulating the phosphors and near-UV chip together with resin,and the structures showed a bright reddish-orange color.The photoluminescence characteristics indicated that the Y_(10)Ta_(4)O_(25):Eu^(3+)phosphor is promising for LEDs.The results are helpful in developing new reddish-orange emitting materials by introducing Eu^(3+)as a structural probe for doping sites and microstructures.展开更多
Electrocatalytic water cracking for hydrogen evolution has drawn attention from researchers owing to its high efficiency.Polymolybdate has excellent redox behaviors and an O-rich surface,becoming attractive electrocat...Electrocatalytic water cracking for hydrogen evolution has drawn attention from researchers owing to its high efficiency.Polymolybdate has excellent redox behaviors and an O-rich surface,becoming attractive electrocatalytic materials.In this work,iso-and hetero-polymolybdate anions were introduced in the crystalline metal-organic coordination system as electrocatalytic electrode material for hydrogen evolution reactions.Semi-rigid bi-pyrazole bi-amide ligand was taken as the organic component,and four complexes were yielded under hydrothermal conditions.The reconstruction and oriented immobilization of polymolybdate occur during the assembly of the architectures,owing to the potential template effect from the metal-organic units.This phenomenon influences the distribution of active sites from polymolybdate.The discrete[AlMo6(OH)_(7)O_(17)]^(2-)anions in complex 3 were immobilized among the directionally arranged metal-organic chains and exposed more active sites.The carbon cloth-based electrode modified by complex 3 possesses obvious electrocatalytic activity by achieving a low overpotential of 17.0 mV at a current density of 10 mA cm^(-2) in 1 M KOH for the hydrogen evolution reaction.Meanwhile,an overpotential of 33.7 mV can be achieved when the current density is 10 mA cm^(-2) in simulated seawater.展开更多
Metal organic framework(MOF)based semiconductor composites enhance the synergistic physiochemical properties of pristine semiconducting materials.In general,MOFs are perceived as an attractive candidate for constructi...Metal organic framework(MOF)based semiconductor composites enhance the synergistic physiochemical properties of pristine semiconducting materials.In general,MOFs are perceived as an attractive candidate for constructing new composite materials because of their facile synthesis,tuneable porosity,high surface area,populous active sites and surface functional groups.As such,many researchers have infused pure MOFs with other classes of materials such as supplementary MOFs,carbonaceous materials,oxides,metal NPs,quantum dots,polymers etc.to fabricate distinctive constructs with synergetic properties.Considering the accelerating development occurring in the field of 3D reticulated hybrid materials towards photocatalysis,it is quite essential to summarize and explore their vast possibilities.In this regard,we aim at performing an analysis of metal oxide integrated MOFs(MO@MOF)towards photocatalytic applications.Many researchers have been tempted to improve the functionalities of pristine MOFs by composite formation with metal oxides(such as UiO-66@WO_(3),Bi_(2) O_(3)@HKUST-1,ZnO@ZIF-8,Fe_(3)O_(4)@MIL-100(Fe)etc.)and have reported its applications towards diverse areas of photo-catalysis.In this context,we have presented a holistic summarization focusing on the rational design,fabrication strategy,characterization aspects and underlying mechanistic charge dynamics of photocatalytic applications with metal oxide integrated metal organic frameworks.展开更多
Shape-memory effects and stimuli-induced phase transformations are observed across many types of materials but remain understudied in molecular materials.In this contribution,we revisit the Werner complex,[Ni(4-MePy)_...Shape-memory effects and stimuli-induced phase transformations are observed across many types of materials but remain understudied in molecular materials.In this contribution,we revisit the Werner complex,[Ni(4-MePy)_(4)(NCS)_(2)](4-MePy=4-methylpyridine),a molecular material that has long been known to form Werner clathrates and possess a porous polymorph.Whereas earlier work implied that[Ni(4-MePy)_(4)(NCS)_(2)]could be a shape-memory material,we confirmed this to be the case through p-xylene(PX)vapor sorption studies.Specifically,[Ni(4-MePy)_(4)(NCS)_(2)]transformed from its reported nonporousαphase to the PX-loadedβphase induced by PX vapour.βreversibly transformed to its porousβ’phase upon PX removal over at least three PX sorption cycles.β’reverted toαupon heating at 80℃in a closed vessel.The porosity ofβ’was explored by examining its C_(3)H_(x)(x=4,6,and 8)gas sorption properties,which revealed vip size/shape-dependent sorption behaviour with uptakes of 0.6,0.9 and 1.6 mol mol^(-1)for C_(3)H_(8),C_(3)H_(6)and C_(3)H_(4),respectively.Insight into the structural transformations of theα,β,andβ’phases is provided by analysis of their previously reported crystal structures and new density functional theory calculations.展开更多
Traditional tin(Sn)-based oxide materials suffer from huge volume expansion/contraction during discharge/charge cycling,resulting in poor cyclic stability when they are used as anode materials.In comparison,the bimeta...Traditional tin(Sn)-based oxide materials suffer from huge volume expansion/contraction during discharge/charge cycling,resulting in poor cyclic stability when they are used as anode materials.In comparison,the bimetal Sn-based oxides have gained increasing attention in the field of rechargeable sodium ion batteries(SIBs)because of the synergism between the metal components,which prevents agglomeration of the active particles.In this work,the electrochemical performances of copper tin oxide(CuSnO_(3))as an anode material for SIBs were investigated for the first time.展开更多
Defects in crystalline structures play a vital role in their properties,so their proper characterization is essential to understanding and improving the behaviour of the materials.In this work,their presence in Ca_(4)...Defects in crystalline structures play a vital role in their properties,so their proper characterization is essential to understanding and improving the behaviour of the materials.In this work,their presence in Ca_(4)Fe_(9)O_(17) has been analysed.Its structure exhibits three different iron coordination topologies and can be described as layers of corner-sharing FeO_(5) bipyramids stacked along the c axis together with layers of edge-sharing FeO_(6) octahedra,both being linked by FeO_(4) tetrahedra.The relative position of the FeO_(4) tetrahedra generates three possible stacking directions,which results in stacking faults when more than one is combined.Structural refinement using the Rietveld method in X-ray and neutron powder diffraction data was not possible due to significant mismatches between the observed and calculated integrated intensities for several peaks resulting from this atomic disorder.Selected area electron diffraction(SAED)and high-resolution scanning transmission electron microscopy(HR-STEM)images confirm the local defective nature of the material.The FAULTS software enabled a successful refinement of the structure considering a high concentration of planar defects,conferred by the existence of three possible stacking directions in the crystal structure,all of them confined in the basal plane.展开更多
Topological superconductors have garnered significant attention due to their potential for realizing topological quantum computation.However,a universal computational tool based on first-principles calculations for pr...Topological superconductors have garnered significant attention due to their potential for realizing topological quantum computation.However,a universal computational tool based on first-principles calculations for predicting topological superconductivity has not yet been fully developed,posing substantial challenges in identifying topological superconducting materials.In this paper,we present a numerical method to characterize the superconducting spectrum and topological invariants of two-dimensional(2D)slab systems using first-principles band structure,implemented in the open-source software WannierTools.To more accurately model the superconducting proximity effect,we integrate a phenomenological theory of SC pairing decay module into the program.Our approach can be applied to classical superconductor-topological insulator(SC-TI)heterostructures,SC-semiconductor heterostructures,and intrinsic topological superconductors.The program’s validity is demonstrated using the topological crystal insulator SnTe,the Rashba semiconductor InSb,and the superconductor NbSe2 as examples.We anticipate that this tool will accelerate the discovery of topological superconductor candidates.展开更多
Machine learning(ML)offers considerable promise for the design of new molecules and materials.In real-world applications,the design problem is often domain-specific,and suffers from insufficient data,particularly labe...Machine learning(ML)offers considerable promise for the design of new molecules and materials.In real-world applications,the design problem is often domain-specific,and suffers from insufficient data,particularly labeled data,for ML training.In this study,we report a data-efficient,deep-learning framework for molecular discovery that integrates a coarse-grained functional-group representation with a self-attention mechanism to capture intricate chemical interactions.Our approach exploits group-contribution concepts to create a graph-based intermediate representation of molecules,serving as a low-dimensional embedding that substantially reduces the data demands typically required for training.Using a self-attention mechanism to learn the subtle but highly relevant chemical context of functional groups,the method proposed here consistently outperforms existing approaches for predictions of multiple thermophysical properties.In a case study focused on adhesive polymer monomers,we train on a limited dataset comprising only 6,000 unlabeled and 600 labeled monomers.The resulting chemistry prediction model achieves over 92%accuracy in forecasting properties directly from SMILES strings,exceeding the performance of current state-of-the-art techniques.Furthermore,the latent molecular embedding is invertible,enabling the design pipeline to automatically generate new monomers from the learned chemical subspace.We illustrate this functionality by targeting several properties,including high and low glass transition temperatures(Tg),and demonstrate that our model can identify new candidates with values that surpass those in the training set.The ease with which the proposed framework navigates both chemical diversity and data scarcity offers a promising route to accelerate and broaden the search for functional materials.展开更多
基金Guangzhou Science and Technology Project,China(No.201904010213)。
文摘Metal-organic frameworks(MOFs)have potential application prospects in the electrochemical energy storage and conversion area on account of their high specific surface area,high porosity,tunable pore size,and structural diversity when compared to traditional porous materials.In order to expand the application scope of MOFs,thermal decomposition can be carried out via calcination treatment in order to convert them into porous metal oxide materials.In this review,we summarize the synthetic methods of MOF-derived transition metal oxide(TMO)composites and their applications in lithium-ion batteries(LIBs)as anodes.A variety of TMOs and composites with different structures and morphologies derived from MOFs based on several types of ligands,including 1,4-benzenedicarboxylic acid(H_(2)BDC),1,3,5-benzenetricarboxylic acid(H_(3)BTC),2-methylimidazole,ferricyanide,and other unusual organic linkers,have been discussed.Finally,current challenges and possible solutions of MOF-derived anode materials have been proposed.
基金supported by the Sichuan Foundation for Distinguished Young Scholars(2022JDJQ0049)the Chengdu International Science and Technology Cooperation Fund(Grant 2019-GH02-00074-HZ)+1 种基金the Chengdu Science and Technology Bureau(Grant 2021-YF05-00698-SN)the Scientific and Technological Achievements Transformation Fund of West China Hospital,Sichuan University(Grant CGZH21002).
文摘Manganese dioxide(MnO_(2)),a type of redox-active transition-metal dioxide,has found wide applications in catalysts,oxidants,ferrites,achromats and battery materials.In addition,MnO_(2) is also increasingly being used in the biomedical field for disease diagnosis and treatment.Despite its great potential,there are limited articles that comprehensively review the use of MnO_(2) in disease diagnosis and treatment.This review provides a concise overview of the latest developments in MnO_(2) nanomaterials,focusing on their applications as magnetic resonance,photoacoustic and fluorescent contrast agents.We first summarize the preparation methods of MnO_(2) nanomaterials and the mechanisms by which they serve as magnetic resonance contrast agents.We then briefly introduce their applications as photoacoustic and fluorescent contrast agents.Finally,we provide an overview of the therapeutic applications of MnO_(2) nanomaterials and discuss the challenges and prospects for their future clinical applications.
基金supported by the National Nature Science Foundation of China(grant number 22201134)the Natural Science Foundation for Colleges and Universities of Jiangsu Province(grant number 22KJB150028).
文摘Ferroelectric materials have broad application prospects in photovoltaics,energy storage,information storage and other fields;however,obtaining ferroelectric materials through rational molecular design remains a challenge.Noncentrosymmetric crystallization,directional arrangement of dipoles and an appropriate flipping barrier are all key difficulties in constructing ideal ferroelectric materials.In this article,a novel hybrid material,TDMHACdCl_(3)(1,where TDMHA^(+)is N-(tert-butyl)-N,N-dimethylhydroxylammonium),exhibiting ferroelectric properties was successfully synthesized and characterized.A CH_(3)/OH substitution strategy was employed to form a hydrogen bond between the organic cation and the inorganic framework,deflecting the dipole moment direction of the cation.To minimize the energy of the crystal lattice,hydrogen bonds compete with the cation conformation,causing the cations to deviate from the optimal conformation and allowing the dipoles to be oriented in one direction.The crystal structure and quantum chemical calculations are thoroughly discussed to reveal the origin of the ferroelectric property in this work.We believe that our design strategy will contribute to the discovery of more ferroelectric materials.
基金financially supported by the National Natural Science Foundation of China(51877216,21773309,21805307,21905300)the Natural Science Foundation of Shandong Province(ZR2020MB078),the Taishan Scholar Foundation(tsqn20161017,tspd20210308)+4 种基金theMajor Program of Shandong Province Natural Science Foundation(ZR201801280009)the PetroChinaInnovation Foundation(2018D-5007-0504)the Fundamental Research Funds for the Central Universities(18CX05007A,19CX05001A,19CX05002A)the Key Projects of China NationalKey R&D Plan(2018YFE0118200)the“111”Program of National College Disciplinary Innovation(B13031).
文摘Aqueous sodium-ion batteries(ASIBs)promise particularly increased operational safety and lower manufacturing cost than the current state-of-the-art organic electrolyte-based lithium-ion batteries.However,the output voltages of reported ASIBs are still restricted to under 1.5 V due to the generally high redox potentials of currently reported anode materials.In this work,we innovatively selected FeSe_(2)as the anode material for an ASIB to obtain a high output voltage.
文摘The emerging area of halide solid electrolytes has garnered significant interest due to its superior ionic conductivity,broad electrochemical stability range,and strong compatibility with positive electrode materials.In recent times,there has been a continuous emergence of diverse halide systems.This study provides a comprehensive review of the synthesis strategies classification schemes,structural attributes,ion transport mechanisms,and modified means of halides.Notably,the paper delves into a detailed analysis of the structural details and ion conduction mechanisms of several representative halides.Furthermore,this review also examines the intrinsic connection between the recently discovered oxyhalides and halides and figures out the primary obstacles and prospective directions for advancement through a thorough review and analysis.
基金supported by the National Key Research and Development Program of China(2017YFF0204706)the Program of Introducing Talents and Discipline Innovation to Universities 2017(X2017004)。
文摘Thermoelectrics is a research area that focuses on the development of high-performance materials for direct thermal and electrical energy conversion in power generation and solid-state cooling.Ever since Ioffe’s inference in 1950s that heavily doped semiconductors make the best thermoelectrics,inorganic semiconductors and semimetals have remained the cornerstone of high-performance thermoelectric materials.In this article,we review the recent advances in inorganic material thermoelectrics with special emphases on:(i)the complementary local-global view of material and the roles of configurational entropy and Fermi surface complexity in material screening;(ii)the emerging schemes of resonant bonding,dynamic disorder,“gap”engineering,pudding-mold-shaped bands in material performance enhancement;(iii)a list of promising bulk materials,such as host-vip structures,half-Heusler compounds,silicides,Zintl phases,and incommensurate structures;and(iv)state-of-the-art materials synthesis and fabrication techniques.These advances will facilitate the development of next-generation bulk thermoelectric materials.
基金funded by the Major Research Plan of the National Natural Science Foundation of China,no.91963101the National Natural Science Foundation of China,no.22175072.
文摘Surface modification is a simple and efficient method to enhance the gas sensing properties of semiconductor materials.In this paper,Fe_(2)O_(3)nanoparticle-decorated ZnO nanorods are successfully fabricated by a facile two-step synthesis method.The SEM,TEM and XPS results indicate that the Fe_(2)O_(3)nanoparticles grow directly on the surface of ZnO nanorods.The gas sensing properties of pure ZnO and Fe_(2)O_(3)/ZnO nanocomposites have been systematically analyzed.The gas response value of a 1 wt%Fe_(2)O_(3)/ZnO sample is 14.5 to 100 ppm triethylamine(TEA)at the optimal operating temperature of 260℃,which is about 3 times that of pure ZnO(5.0).In addition,the 1 wt%Fe_(2)O_(3)/ZnO sensor reflects a rapid response/recovery time(1 s/14 s).The density functional theory(DFT)simulation results confirm that after the Fe_(2)O_(3)cluster modifies the surface of ZnO,the atomic position at the interface changes significantly and the structure of Fe_(2)O_(3)/ZnO has the lowest adsorption energy for TEA molecules;these are the key factors for improving the gas sensitivity of the composite sample.
基金support from the National Natural Science Foundation of China(22171109 and 22001097)the Natural Science Foundation of Jiangsu Province of China(BK20201003)+1 种基金the Postdoctoral Research Foundation of China(2021M701657)the Shenzhen Science and Technology Program(KQTD20170330110107046).
文摘Geometric isomers are very important and interesting in the field of optical materials.In this work,we have designed and synthesized a new series of geometric isomers of iridium complexes featuring three charged(0,-1,-2)ligands,which contain a rigid asymmetric four-membered Ir-N-C-S chelating ring.The reaction of iridium complex precursors(2a and 2b)with an equal amount of the four-membered ring S^N ligand at a low temperature produces the kinetic isomers Ir1K and Ir2K,while a higher temperature leads to the formation of their corresponding thermodynamic isomers Ir1T and Ir2T.The X-ray diffraction analysis shows that the kinetic isomers exhibit a trans-S^N configuration,which is in contrast with the trans-N^N configuration of the thermodynamic isomers,and their coordination bond lengths,bond angles and packing patterns are also quite different.More importantly,all isomers showed efficient deepred emission(619-676 nm),and the thermodynamic isomers have shorter emission wavelengths,longer excited state lifetimes and higher luminescent efficiencies than their corresponding kinetic isomers.Theoretical calculations show that the four-membered ring S^N ligand in the thermodynamic isomers is more involved in the excited state than that in the kinetic isomers,and the^(3)MLCT effects are more pronounced in the thermodynamic isomers.Notably,OLED devices incorporating both thermodynamic and kinetic isomers(Ir2T and Ir2K)as emitting layers can achieve good maximum external quantum efficiencies(EQEs)(5.0%and 4.6%)peaking at 642 nm and 643 nm of the deep-red region with CIE coordinates(0.675,0.323)and(0.668,0.329),respectively,accompanied by a low turn-on voltage(3.0 V).This study provides an important strategy for the design of deep-red emitting geometric isomers of iridium complexes and their photoelectric applications.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(2020R1F1A1049740)the National Natural Science Foundation of China(NSFC)(Grant No.62074019 and 62174016)+1 种基金the Suzhou Science and Technology Project(Grant No.SZS2020313)Xifeng Yang and Yushen Liu also acknowledge the support of the Qing Lan Project of Jiangsu Province.
文摘Inorganic compounds with fluorite-related structures are among the well-known multifunctional materials.In this work,Y_(10)Ta_(4)O_(25):Eu^(3+)with a fluorite-related structure was prepared using the ceramic synthesis method.XRD patterns and Rietveld refinements were used to verify the phase formation with an orthorhombic space group of Cmmm(65).The relationship between the luminescence properties and structural characteristics was studied in detail.Compared with earlier reported phosphors,Y_(10)Ta_(4)O_(25):Eu^(3+)exhibits peculiar luminescence characteristics.The transition peaks from ^(5)D_(0) to ^(7)F_(1),^(7)F_(2),and ^(7)F_(4)(570-720 nm)all showed fairly strong intensities,and emission transitions from the high excited states ^(5)D_(1,2,3) were detected at room temperature,etc.The experiments confirmed that the peculiar luminescence of Y_(10)Ta_(4)O_(25):Eu^(3+)is due to its distinctive structure,such as the strong covalent nature and high polarizability of the(Y/Eu)O8 polyhedron in the lattice.The doping mechanism was investigated using the spectroscopy probe of Eu^(3+)by laser site-selective excitation and emission in the ^(5)D_(0)→^(7)F0 region.Eu^(3+)ions mostly tend to preferentially occupy the Y1 sites first,which show shorter bond lengths and significant electronic repulsion in the(Y/Eu)O8 polyhedron.The phosphor exhibited a high quantum efficiency of 45% and good thermal stability.Some light-emitting diode lighting devices were fabricated by encapsulating the phosphors and near-UV chip together with resin,and the structures showed a bright reddish-orange color.The photoluminescence characteristics indicated that the Y_(10)Ta_(4)O_(25):Eu^(3+)phosphor is promising for LEDs.The results are helpful in developing new reddish-orange emitting materials by introducing Eu^(3+)as a structural probe for doping sites and microstructures.
基金supported by the Research Foundation of Education Bureau of Liaoning Province(LJKQZ20222290)the National Natural Science Foundation of China(No.21971024,21671025)+1 种基金Liao Ning Revitalization Talents Program(XLYC1902011)which are gratefully acknowledged.
文摘Electrocatalytic water cracking for hydrogen evolution has drawn attention from researchers owing to its high efficiency.Polymolybdate has excellent redox behaviors and an O-rich surface,becoming attractive electrocatalytic materials.In this work,iso-and hetero-polymolybdate anions were introduced in the crystalline metal-organic coordination system as electrocatalytic electrode material for hydrogen evolution reactions.Semi-rigid bi-pyrazole bi-amide ligand was taken as the organic component,and four complexes were yielded under hydrothermal conditions.The reconstruction and oriented immobilization of polymolybdate occur during the assembly of the architectures,owing to the potential template effect from the metal-organic units.This phenomenon influences the distribution of active sites from polymolybdate.The discrete[AlMo6(OH)_(7)O_(17)]^(2-)anions in complex 3 were immobilized among the directionally arranged metal-organic chains and exposed more active sites.The carbon cloth-based electrode modified by complex 3 possesses obvious electrocatalytic activity by achieving a low overpotential of 17.0 mV at a current density of 10 mA cm^(-2) in 1 M KOH for the hydrogen evolution reaction.Meanwhile,an overpotential of 33.7 mV can be achieved when the current density is 10 mA cm^(-2) in simulated seawater.
基金S‘O’A(Deemed to be University),Bhubaneswar management and staff are thankfully acknowledged for their constant support and encouragement in this work.
文摘Metal organic framework(MOF)based semiconductor composites enhance the synergistic physiochemical properties of pristine semiconducting materials.In general,MOFs are perceived as an attractive candidate for constructing new composite materials because of their facile synthesis,tuneable porosity,high surface area,populous active sites and surface functional groups.As such,many researchers have infused pure MOFs with other classes of materials such as supplementary MOFs,carbonaceous materials,oxides,metal NPs,quantum dots,polymers etc.to fabricate distinctive constructs with synergetic properties.Considering the accelerating development occurring in the field of 3D reticulated hybrid materials towards photocatalysis,it is quite essential to summarize and explore their vast possibilities.In this regard,we aim at performing an analysis of metal oxide integrated MOFs(MO@MOF)towards photocatalytic applications.Many researchers have been tempted to improve the functionalities of pristine MOFs by composite formation with metal oxides(such as UiO-66@WO_(3),Bi_(2) O_(3)@HKUST-1,ZnO@ZIF-8,Fe_(3)O_(4)@MIL-100(Fe)etc.)and have reported its applications towards diverse areas of photo-catalysis.In this context,we have presented a holistic summarization focusing on the rational design,fabrication strategy,characterization aspects and underlying mechanistic charge dynamics of photocatalytic applications with metal oxide integrated metal organic frameworks.
基金support of Science Foundation Ireland(16/IA/4624)the Irish Research Council(IRCLA/2019/167)+1 种基金a startup fund from the Agency for Science,Technology and Research(SC25/22-119116)the support from the Agency for Science,Technology and Research under the Manufacturing,Trade and Connectivity(MTC)Programmatic funding scheme(M23L8b0049).
文摘Shape-memory effects and stimuli-induced phase transformations are observed across many types of materials but remain understudied in molecular materials.In this contribution,we revisit the Werner complex,[Ni(4-MePy)_(4)(NCS)_(2)](4-MePy=4-methylpyridine),a molecular material that has long been known to form Werner clathrates and possess a porous polymorph.Whereas earlier work implied that[Ni(4-MePy)_(4)(NCS)_(2)]could be a shape-memory material,we confirmed this to be the case through p-xylene(PX)vapor sorption studies.Specifically,[Ni(4-MePy)_(4)(NCS)_(2)]transformed from its reported nonporousαphase to the PX-loadedβphase induced by PX vapour.βreversibly transformed to its porousβ’phase upon PX removal over at least three PX sorption cycles.β’reverted toαupon heating at 80℃in a closed vessel.The porosity ofβ’was explored by examining its C_(3)H_(x)(x=4,6,and 8)gas sorption properties,which revealed vip size/shape-dependent sorption behaviour with uptakes of 0.6,0.9 and 1.6 mol mol^(-1)for C_(3)H_(8),C_(3)H_(6)and C_(3)H_(4),respectively.Insight into the structural transformations of theα,β,andβ’phases is provided by analysis of their previously reported crystal structures and new density functional theory calculations.
基金supported by the National Key Research and Development Program of China(2016YFA0202601,2016YFA0202603)the National Natural Science Foundation of China(51521001,51602239)+2 种基金the Programme of Introducing Talents of Discipline to Universities(B17034)the International Science&Technology Cooperation Program of China(2013DFA50840)the Yellow Crane Talent(Science&Technology)Program of Wuhan City and the Fundamental Research Funds for the Central Universities(WUT:2017III009,2017III005).We are grateful to Yun Liang,the Ningbo Institute of Materials Technology and Engineering for drawing the graphics.
文摘Traditional tin(Sn)-based oxide materials suffer from huge volume expansion/contraction during discharge/charge cycling,resulting in poor cyclic stability when they are used as anode materials.In comparison,the bimetal Sn-based oxides have gained increasing attention in the field of rechargeable sodium ion batteries(SIBs)because of the synergism between the metal components,which prevents agglomeration of the active particles.In this work,the electrochemical performances of copper tin oxide(CuSnO_(3))as an anode material for SIBs were investigated for the first time.
基金ALBA synchrotron(proposal 2019073634)ILL(EASY access system)+1 种基金Spain’s Agencia Estatal de Investigación Severo Ochoa Program for Centers of Excellence in R&D(CEX2019-000917-S)funding through grant PID2020-113805GB-I00.
文摘Defects in crystalline structures play a vital role in their properties,so their proper characterization is essential to understanding and improving the behaviour of the materials.In this work,their presence in Ca_(4)Fe_(9)O_(17) has been analysed.Its structure exhibits three different iron coordination topologies and can be described as layers of corner-sharing FeO_(5) bipyramids stacked along the c axis together with layers of edge-sharing FeO_(6) octahedra,both being linked by FeO_(4) tetrahedra.The relative position of the FeO_(4) tetrahedra generates three possible stacking directions,which results in stacking faults when more than one is combined.Structural refinement using the Rietveld method in X-ray and neutron powder diffraction data was not possible due to significant mismatches between the observed and calculated integrated intensities for several peaks resulting from this atomic disorder.Selected area electron diffraction(SAED)and high-resolution scanning transmission electron microscopy(HR-STEM)images confirm the local defective nature of the material.The FAULTS software enabled a successful refinement of the structure considering a high concentration of planar defects,conferred by the existence of three possible stacking directions in the crystal structure,all of them confined in the basal plane.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1607400)the National Natural Science Foundation of China(Grant Nos.12274154 and 12274436)+1 种基金the Science Center of the National Natural Science Foundation of China(Grant No.12188101)the Center for Materials Genome,China.
文摘Topological superconductors have garnered significant attention due to their potential for realizing topological quantum computation.However,a universal computational tool based on first-principles calculations for predicting topological superconductivity has not yet been fully developed,posing substantial challenges in identifying topological superconducting materials.In this paper,we present a numerical method to characterize the superconducting spectrum and topological invariants of two-dimensional(2D)slab systems using first-principles band structure,implemented in the open-source software WannierTools.To more accurately model the superconducting proximity effect,we integrate a phenomenological theory of SC pairing decay module into the program.Our approach can be applied to classical superconductor-topological insulator(SC-TI)heterostructures,SC-semiconductor heterostructures,and intrinsic topological superconductors.The program’s validity is demonstrated using the topological crystal insulator SnTe,the Rashba semiconductor InSb,and the superconductor NbSe2 as examples.We anticipate that this tool will accelerate the discovery of topological superconductor candidates.
基金supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences and Engineering Division.
文摘Machine learning(ML)offers considerable promise for the design of new molecules and materials.In real-world applications,the design problem is often domain-specific,and suffers from insufficient data,particularly labeled data,for ML training.In this study,we report a data-efficient,deep-learning framework for molecular discovery that integrates a coarse-grained functional-group representation with a self-attention mechanism to capture intricate chemical interactions.Our approach exploits group-contribution concepts to create a graph-based intermediate representation of molecules,serving as a low-dimensional embedding that substantially reduces the data demands typically required for training.Using a self-attention mechanism to learn the subtle but highly relevant chemical context of functional groups,the method proposed here consistently outperforms existing approaches for predictions of multiple thermophysical properties.In a case study focused on adhesive polymer monomers,we train on a limited dataset comprising only 6,000 unlabeled and 600 labeled monomers.The resulting chemistry prediction model achieves over 92%accuracy in forecasting properties directly from SMILES strings,exceeding the performance of current state-of-the-art techniques.Furthermore,the latent molecular embedding is invertible,enabling the design pipeline to automatically generate new monomers from the learned chemical subspace.We illustrate this functionality by targeting several properties,including high and low glass transition temperatures(Tg),and demonstrate that our model can identify new candidates with values that surpass those in the training set.The ease with which the proposed framework navigates both chemical diversity and data scarcity offers a promising route to accelerate and broaden the search for functional materials.
