Room-temperature phosphorescence(RTP)materials exhibiting long emission lifetimes have gained increasing attention owing to their potential applications in encryption,anti-counterfeiting,and sensing.However,most polym...Room-temperature phosphorescence(RTP)materials exhibiting long emission lifetimes have gained increasing attention owing to their potential applications in encryption,anti-counterfeiting,and sensing.However,most polymers exhibit a short RTP lifetime(<1 s)because of their unstable triplet excitons.Herein,a new strategy of polymer chain stabilized phosphorescence(PCSP),which yields a new kind of RTP polymers with an ultralong lifetime and a sensitive oxygen response,has been reported.The rigid polymer chains of poly(methyl mathacrylate)(PMMA)immobilize the emitter molecules through multiple interactions between them,giving rise to efficient RTP.Meanwhile,the loosely-packed amorphous polymer chains allow oxygen to diffuse inside,endowing the doped polymers with oxygen sensitivity.Flexible and transparent polymer films exhibited an impressive ultralong RTP lifetime of 2.57 s at room temperature in vacuum,which was among the best performance of PMMA.Intriguingly,their RTP was rapidly quenched in the presence of oxygen.Furthermore,RTP microparticles with a diameter of 1.63μm were synthesized using in situ dispersion polymerization technique.Finally,oxygen sensors for quick,visual,and quantitative oxygen detection were developed based on the RTP microparticles through phosphorescence lifetime and image analysis.With distinctive advantages such as an ultralong lifetime,oxygen sensitivity,ease of fabrication,and cost-effectiveness,PCSP opens a new avenue to sensitive materials for oxygen detection.展开更多
Selective oxidation of olefin to epoxides is an important reaction in industry,however,developing heterogeneous catalysts to achieve the effective catalysis for this reaction under O_(2)atmosphere at room temperature ...Selective oxidation of olefin to epoxides is an important reaction in industry,however,developing heterogeneous catalysts to achieve the effective catalysis for this reaction under O_(2)atmosphere at room temperature is challenging but highly desired.In this work,two novel 2D cobalt metal-organic complexes,namely[Co(L)(5-HIP)]·2H_(2)O(Co-MOC-1)and[Co(L)(BTEC)_(0.5)]·H_(2)O(Co-MOC-2)(L=(E)-4,4-(ethene-1,2-diyl))bis(N-(pyridin-3-yl)benzamide;5-H_(2)HIP=5-hydroxyisophthalic acid;H4BTEC=pyromellitic acid)were designed and synthesized through hydrothermal method,which exhibited different metal coordination modes(4-coordinate and 5-coordinate,respectively)and 2D layer structures directed by different carboxylates co-ligands.Two Co-MOCs can serve as heterogeneous catalysts for the selective oxidation of olefins to epoxides at room temperature using O_(2)as oxidant.Furthermore,a higher catalysis activity of Co-MOC-1 than Co-MOC-2(96.7%vs.90.2%yield of 1,2-epoxycyclooctane)was observed,which may be attributed to the coordination unsaturated Co centers,the less coordination number and larger interlayer spacing of Co-MOC-1.展开更多
Phosphorus-based luminescent materials consist of certain phosphorus in the aromatic backbones,endowing a larger nuclear charge(Z,15P),rich valence states for the phosphorus core,and various electron geometries.These ...Phosphorus-based luminescent materials consist of certain phosphorus in the aromatic backbones,endowing a larger nuclear charge(Z,15P),rich valence states for the phosphorus core,and various electron geometries.These features enable promising exploitation for luminescent materials with significant quantum efficiencies and tunable singlet and triplet populations.This mini review focuses on the break-throughs of organic and organometallic phosphorus compounds in advanced circularly polarized fluorescence(CPF)and circularly polarized room-temperature phosphorescence(CP-RTP)by unveiling the structure-function relationships,e.g.,design concept,charge transfer(CT)type,chiral conformation,and excited state transition configuration,and the recent applications in optical information encryption,lighting-displaying,and organic light emitting diodes(OLEDs).By dedicated analysis of current progresses,we hope this work will throw insights into phosphorus-based CPF and CP-RTP behaviors and provide a reference for the rational design of high-performance phosphorus-based emitters.展开更多
Bio-based organic room-temperature phosphorescence(RTP)materials have drawn considerable interest due to their potential to replace conventional petroleum-based RTP materials and attain comprehensive full life-cycle c...Bio-based organic room-temperature phosphorescence(RTP)materials have drawn considerable interest due to their potential to replace conventional petroleum-based RTP materials and attain comprehensive full life-cycle carbon reduction,a feat attributable to their renewable,biocompatible,and environmentally friendly characteristics.Bio-based organic RTP materials derived from natural biomass(e.g.,cellulose,lignin,chitosan)or biologically produced substances possess the capacity to spontaneously generate RTP or contribute to its generation.In this paper,the development lineage of bio-based RTP materials is introduced from the above two directions,including different systems,how to construct such systems,and the current progress.With strategies including hydrogen bonding networks,host—vip encapsulation,and polymeric matrices,it achieves RTP lifetimes up to seconds and full visible-band emission.It then explores the application scenarios that emerge from the natural advantages of these materials,including anti-counterfeiting and encryption,environmental monitoring,and bioimaging.Finally,it brieflydiscusses the potential challenges associated with bio-based RTP materials and envisions future development directions for them.While bio-based RTP materials rival petroleum-based counterparts in RTP efficiency,challenges persist:high production costs,poor environmental/thermal stability,and balancing degradability with durability.These sustainable alternatives offer biodegradability,renewability,and reduced lifecycle carbon emissions,utilizing agricultural byproducts(e.g.,corn stalks,shrimp shells)to enhance circular economies.展开更多
Room-temperature sodium-sulfur(RT Na-S)batteries have been regarded as promising energy storage technologies in grid-scale stationary energy storage systems due to their low cost,natural abundance,and high-energy dens...Room-temperature sodium-sulfur(RT Na-S)batteries have been regarded as promising energy storage technologies in grid-scale stationary energy storage systems due to their low cost,natural abundance,and high-energy density.However,the practical application of RT Na-S batteries is hindered by low reversible capacity and unsatisfying long-cycling performance arising from the severe shuttle effect and sluggish S redox kinetics.This review provides an overview of recent efforts for the optimization strategies of the electronic structure of catalysts via catalyst engineering to enhance the adsorption and catalytic activity toward soluble long-chain sodium polysulfides(NaPSs).Finally,the current challenges and prospects for further optimization strategies of catalysts,understanding catalysis and structural evolution mechanism,and achieving practical applications are highlighted to meet the commercial requirements of RT Na-S batteries.展开更多
La0.5Sm0.2Sr0.3MnO3/（Ag2O）x/2 （x = 0.00, 0.04, 0.08, 0.25, 0.30） samples were prepared by the solid-state reaction method, and their transport behaviors, transport mechanism, and magnetoresistance effect were stud...La0.5Sm0.2Sr0.3MnO3/（Ag2O）x/2 （x = 0.00, 0.04, 0.08, 0.25, 0.30） samples were prepared by the solid-state reaction method, and their transport behaviors, transport mechanism, and magnetoresistance effect were studied through the measurement and fitting of p-T curves. The results show that the element Ag takes part in reaction when the doping amount is small. Ag is mainly distributed at the grain boundary of the host material and is in metallic state when the doping amount is relatively large; then the system becomes a two-phase composite. A small amount of Ag doping can apparently increase grain-boundary magnetoresistance induced by the spin-dependent scattering. The resistivity of the sample doped with 30 mol% Ag is one order of magnitude smaller than that of low-doped samples, and its magnetoresistance in the magnetic field of 0.5 T and at 300 K is strengthened apparently reaching 9.4%, which is connected not only with the improvement of the grain-boundary structure of the host material but also with the decrease of material resistivity.展开更多
Near-equiaxed β grain was achieved in the near-α Ti60(Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C) titanium alloy via laser directed energy deposition(LDED). The microstructural evolution along the building d...Near-equiaxed β grain was achieved in the near-α Ti60(Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C) titanium alloy via laser directed energy deposition(LDED). The microstructural evolution along the building direction and the room-temperature tensile properties along the horizontal and vertical directions(building direction) were systematically studied through SEM and OM. EBSD and XRD were utilized to accurately demonstrate the texture of the α and β phases. The results showed that the α phase presented a low texture intensity, which was ascribed to the weak textured β grain with near-equiaxed morphology, since there are Burgers orientation relationships during the β →α transition. In addition, numerical simulation, combined with the CET curve of Ti60 alloy considering the effect of multi-composition,was utilized to elucidate the formation mechanism of the near-equiaxed β grains. Furthermore, according to the solidification theory, we proposed that the solidification temperature range ΔTfwas more accurate than the growth restriction factor Q in predicting the formation tendency of equiaxed β grain in different titanium alloys. Tensile results showed that the horizontal and vertical samples had similar strength,while the former exhibited larger elongation than the latter. The effect of the near-equiaxed β grain and the internal α phase on mechanical properties were revealed at last.展开更多
This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and ...This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and status are investigated.A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio(72%S).In contrast,a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio(44%S).In carbonate ester electrolyte,only the sulfur trapped in porous structures is active via‘solid-solid’behavior during cycling.The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents.To improve the capacity of the sulfur-rich cathode,ether electrolyte with NaNO_(3) additive is explored to realize a‘solid-liquid’sulfur redox process and confine the shuttle effect of the dissolved polysulfides.As a result,the sulfur-rich cathode achieved high reversible capacity(483 mAh g^(−1)),corresponding to a specific energy of 362 Wh kg^(−1) after 200 cycles,shedding light on the use of ether electrolyte for high-loading sulfur cathode.展开更多
GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high...GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high carrier concentration.Here,we successfully enhance the Seebeck coefficient of GeTe from~30 to 220μV·K^(−1) at 300 K,which is achieved by AgInSe2 alloying and Bi doping.It is demonstrated that Bi doping helps to optimize the Seebeck coefficient without deteriorating the intrinsic electrical transport properties of the matrix.A high room-temperature power factor(PF)of~11μW·cm^(−1)·K^(−2) is achieved for a wide range of Bi-doped samples.The simultaneously introduced abundant point defects cause mass and strain fluctuations,which decrease the lattice thermal conductivity(κ_(L))to a low value of 0.6 W·m^(−1)·K^(−1) at 300 K.Due to the synergetic effects of Bi doping in AgInSe2-alloyed GeTe,a high room-temperature ZT value of 0.46 is obtained together with a high ZT value of 1.1 at 523 K.展开更多
Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for...Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for transforming the fascinating properties at the nanoscale into the macroscopic scale for practical applications.Herein,suitable cross-linking agents(amino-propyltriethoxysilane,Mn^(2+),Fe^(2+),Zn^(2+),and Co^(2+)) as interfacial mediators to engineer the interlayer interactions are reported to realize the graphene oxide(GO)-assisted assembly of Ti_(3)C_(2)T_(x) MXene aerogel at room temperature.This elaborate aerogel construction not only suppresses the oxidation degradation of Ti_(3)C_(2)T_(x) but also generates porous aerogels with a high Ti_(3)C_(2)T_(x) content(87 wt%) and robustness,thereby guaranteeing the functional accessibility of Ti_(3)C_(2)T_(x) nanosheets and operational reliability as integrated functional materials.In combination with a further sulfur modification,the Ti_(3)C_(2)T_(x) aerogel electrode shows promising electrochemical performances as the freestanding anode for sodium-ion storage.Even at an ultrahigh loading mass of 12.3 mg cm^(-2),a pronounced areal capacity of 1.26 mAh cm^(-2) at a current density of 0.1 A g^(-1) has been achieved,which is of practical significance.This work conceptually suggests a new way to exert the utmost surface functionalities of MXenes in 3D monolithic form and can be an inspiring scaffold to promote the application of MXenes in different areas.展开更多
Room-temperature phosphorescence（RTP） materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes.In this short review,recent progress on enhanc...Room-temperature phosphorescence（RTP） materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes.In this short review,recent progress on enhancement of RTP from purely organic materials is summarized.According to the mechanism of phosphorescence emission,two principles are discussed to construct efficient RTP materials：one is promoting intersystem crossing（ISC） efficiency by using aromatic carbonyl,heavyatom,or/and heterocycle/heteroatom containing compounds;the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states,including embedding phosphors into polymers and packing them tightly in crystals.With aforementioned strategies,RTP from purely organic materials was achieved both in fluid and rigid media.展开更多
Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL ...Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL and ultralong RTP(to naked eyes ~14 s) are successfully achieved in CDs system. Encoding information and patterns fabricated by directly screen-printing method are invisible to eyes under natural light. Interestingly, clear and multicolor patterns with tunable FL and RTP emissions are identified under the 365 nm, 395 nm and 465 nm excitation and removal of them, indicating potential application of carbon dots with different FL and RTP outputs in the high-level photonic anti-counterfeiting field.展开更多
Synthesis and applications of three-dimensional(3 D)porous graphene frameworks(GFs)have attracted extensive interest owing to their intriguing advantages of high specific surface area,enriched porosity,excellent elect...Synthesis and applications of three-dimensional(3 D)porous graphene frameworks(GFs)have attracted extensive interest owing to their intriguing advantages of high specific surface area,enriched porosity,excellent electrical conductivity,exceptional compressibility and processability.However,it is still challenging for economically viable,fast and scalable assembly of 3 D GFs at room-temperature.Herein,we reported a one-step scalable strategy for fast self-assembly of graphene oxide into 3 D macroscopically porous GFs,with assistance of polyoxometalates(POM)as functional cross-linker and hydrazine hydrate as reductant at room-temperature.The resulting 3 D interconnected macroporous POM-GFs uniformly decorated with ultrasmall POM nanoclusters were directly processed into binder-/additive-free film compact electrodes(1.68 g cm^(-3))with highly aligned,layer-stacked structure and electrically conductivity(622 S m-1)for high-performance supercapacitors,showing an impressive gravimetric capacitance of205 F g-1,volumetric capacitance of 334 F cm^(-3) at 1 mV s^(-1),and remarkable cycling stability with capacitance retention of 83%after 10,000 cycles,outperforming the most reported GFs.Further,the solid-state supercapacitors offered excellent gravimetric capacitance of 157 F g-1 exceptionally volumetric capacitance of 115 F cm^(-3) at 2 mV s^(-1) based on single electrode,and volumetric energy density of2.6 mWh cm^(-3).Therefore,this work will open novel opportunities to room-temperature fast assembly of 3 D porous graphene architectures for high-energy-density supercapacitors.展开更多
Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. ...Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.展开更多
Reducing the hot working temperature and high-temperature deformation resistance of titanium alloy to improve hot rolling and hot extrusion workability of products with thin walls and complex section shapes has always...Reducing the hot working temperature and high-temperature deformation resistance of titanium alloy to improve hot rolling and hot extrusion workability of products with thin walls and complex section shapes has always been an important topic in the field of titanium alloy processing.This paper proposed a strategy of adding Mo and Fe elements to simultaneously reduce the hot working temperature and high-temperature deformation resistance of Ti-6Al-4V alloy.The effects of Mo and Fe contents on the mi-crostructure,β transus temperature(Tp),and high-temperature flow stress(HFS)of Ti-6Al-4V-xMo-xFe(x=0-5)alloys were investigated.The results showed that adding Mo and Fe can substantially reduce the Tp and HFS of the alloy,and greatly improve its room-temperature strength.Compared with com-mercial Ti-6Al-4V samples,the T_(β) of Ti-6Al-4V-2Mo-2Fe and Ti-6Al-4V-3Mo-3Fe samples was decreased by 68-98 ℃,and the HFS at 800-900 ℃ was decreased by 37.8%-46.0%.Compared with hot-rolled Ti-6Al-4V samples,the room-temperature tensile strength of hot-rolled Ti-6Al-4V-2Mo-2Fe samples was increased by about 30%,while the elongation hardly decreased.The increased strength was mainly at-tributed to fine grain strengthening and solid solution strengthening.The hot workability and room-temperature strength of Ti-6Al-4V alloy can be significantly improved by adding 2-3 wt.%Mo and Fe simultaneously.展开更多
Stabilizing triplet excited states is important for room temperature phosphorescence(RTP)materials to achieve multifunctional applications in humid environment.However,due to the lack of preparation strategies,the rea...Stabilizing triplet excited states is important for room temperature phosphorescence(RTP)materials to achieve multifunctional applications in humid environment.However,due to the lack of preparation strategies,the realization of RTP materials in water still faces challenges.Herein,a new design strategy was presented to achieve RTP in water by confining carbonized polymer dots(CPDs)in amino functional mesoporous silica(MSNs-NH_(2)).The as-prepared MSNs-CPDs aqueous dispersion exhibited blue afterglow,lasting more than 3 s to naked eyes.The triplet excited states were protected from non-radiative deactivation by the double-confinement effect including covalent bonding fixation and mesoporous structure confinement.The MSNs-CPDs inherited the structure of MSNs-NH_(2),so the stability of morphology and properties were superior to CPDs and even most of silica-based CPDs RTP materials.A water-related encryption technique demonstrated the promising application of MSNs-CPDs as smart materials in the field of information security.Besides,the possibility of potential application in ion detection was also explored.展开更多
Metal oxide semiconductors(MOS)-reduced graphene oxide(rGO)nanocomposites have attracted great attention for room-tempe rature gas sensing applications.The development of novel sensing materials is the key issue for t...Metal oxide semiconductors(MOS)-reduced graphene oxide(rGO)nanocomposites have attracted great attention for room-tempe rature gas sensing applications.The development of novel sensing materials is the key issue for the effective detection of ammoniagas at room temperature.In the present work,the novel reduced graphene oxide(rGO)-In2 O3 nanocubes hybrid materials have been prepared via a simple electrostatic self-assembly strategy.Characterization re sults exhibit that the intimate interfacial contact between In2 O3 nanocubes and the rGO sheets are achieved.Particularly,the as-prepared rGO/In2 O3 nanocomposites displayed high sensitivity,fast response and excellent selectivity towards ammonia(NH3)at room-temperature,which clearly uncovers the merit of structural design and rational integration with rGO sheets.The superior gas sensing performance of the rGO/In2 O3 nanocomposites can be attributed to the synergetic effects of rGO sheets and porous In2 O3 nanocubes.The reported synthesis offers a general approach to rGO/MOS-based semiconductor composites for room-temperature gas sensing applications.展开更多
According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-b...According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-biodegradable,thus they produce a mass of waste disposal and cause environmental pollution is-sue.For the purpose of transforming waste into wealth and reducing environmental pollution,nitrogen and sulfur co-doped carbon nanofiber/carbon black(N,S-CNF/CB)composite derived from the discarded cigarette filters is employed to modify glass fiber(GF)separator for the first time in this study.N,S-CNF improves binding ability towards sodium polysulfides(SPSs)by chemisorption.Non-polar CB limits the dissolution of SPSs in the liquid electrolyte by physisorption.The experiment and density functional theory calculation results indicate that a RT-Na/S battery with a N,S-CNF/CB+GF separator exhibits good cycling stability and rate performance.After 100 cycles at a low current rate of 0.1 C,a RT-Na/S battery with a sulfur mass fraction of 71%delivers a discharge capacity of 703 mAh g^(−1).In addition,at a high current rate of 0.5 C,a discharge capacity of 527 mAh g^(−1) is still maintained after 900 cycles with a very low capacity fading rate of 0.035%per cycle.展开更多
Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its ...Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials.展开更多
Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within...Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.展开更多
基金National Natural Science Foundation of China(No.22475241)Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515010826 and 2023A1515012696)the Fundamental Research Funds for the Central Universities(Nos.17lgjc03 and 18lgpy04).
文摘Room-temperature phosphorescence(RTP)materials exhibiting long emission lifetimes have gained increasing attention owing to their potential applications in encryption,anti-counterfeiting,and sensing.However,most polymers exhibit a short RTP lifetime(<1 s)because of their unstable triplet excitons.Herein,a new strategy of polymer chain stabilized phosphorescence(PCSP),which yields a new kind of RTP polymers with an ultralong lifetime and a sensitive oxygen response,has been reported.The rigid polymer chains of poly(methyl mathacrylate)(PMMA)immobilize the emitter molecules through multiple interactions between them,giving rise to efficient RTP.Meanwhile,the loosely-packed amorphous polymer chains allow oxygen to diffuse inside,endowing the doped polymers with oxygen sensitivity.Flexible and transparent polymer films exhibited an impressive ultralong RTP lifetime of 2.57 s at room temperature in vacuum,which was among the best performance of PMMA.Intriguingly,their RTP was rapidly quenched in the presence of oxygen.Furthermore,RTP microparticles with a diameter of 1.63μm were synthesized using in situ dispersion polymerization technique.Finally,oxygen sensors for quick,visual,and quantitative oxygen detection were developed based on the RTP microparticles through phosphorescence lifetime and image analysis.With distinctive advantages such as an ultralong lifetime,oxygen sensitivity,ease of fabrication,and cost-effectiveness,PCSP opens a new avenue to sensitive materials for oxygen detection.
基金financially supported by the National Natural Science Foundation of China(Nos.22271021,21971024,22201021)the Doctoral Scientific Research Foundation of Liaoning Province(No.2022-BS-302)。
文摘Selective oxidation of olefin to epoxides is an important reaction in industry,however,developing heterogeneous catalysts to achieve the effective catalysis for this reaction under O_(2)atmosphere at room temperature is challenging but highly desired.In this work,two novel 2D cobalt metal-organic complexes,namely[Co(L)(5-HIP)]·2H_(2)O(Co-MOC-1)and[Co(L)(BTEC)_(0.5)]·H_(2)O(Co-MOC-2)(L=(E)-4,4-(ethene-1,2-diyl))bis(N-(pyridin-3-yl)benzamide;5-H_(2)HIP=5-hydroxyisophthalic acid;H4BTEC=pyromellitic acid)were designed and synthesized through hydrothermal method,which exhibited different metal coordination modes(4-coordinate and 5-coordinate,respectively)and 2D layer structures directed by different carboxylates co-ligands.Two Co-MOCs can serve as heterogeneous catalysts for the selective oxidation of olefins to epoxides at room temperature using O_(2)as oxidant.Furthermore,a higher catalysis activity of Co-MOC-1 than Co-MOC-2(96.7%vs.90.2%yield of 1,2-epoxycyclooctane)was observed,which may be attributed to the coordination unsaturated Co centers,the less coordination number and larger interlayer spacing of Co-MOC-1.
基金supported by the National Natural Science Foundation of China(No.21871133)the Natural Science Foundation of Jiangsu Province(No.BK20211146)the Science,Technology,and Innovation Commission of Shenzhen Municipality(No.JCYJ20180307153251975)。
文摘Phosphorus-based luminescent materials consist of certain phosphorus in the aromatic backbones,endowing a larger nuclear charge(Z,15P),rich valence states for the phosphorus core,and various electron geometries.These features enable promising exploitation for luminescent materials with significant quantum efficiencies and tunable singlet and triplet populations.This mini review focuses on the break-throughs of organic and organometallic phosphorus compounds in advanced circularly polarized fluorescence(CPF)and circularly polarized room-temperature phosphorescence(CP-RTP)by unveiling the structure-function relationships,e.g.,design concept,charge transfer(CT)type,chiral conformation,and excited state transition configuration,and the recent applications in optical information encryption,lighting-displaying,and organic light emitting diodes(OLEDs).By dedicated analysis of current progresses,we hope this work will throw insights into phosphorus-based CPF and CP-RTP behaviors and provide a reference for the rational design of high-performance phosphorus-based emitters.
基金financial support from the National Natural Science Foundation of China(22125803,T2488302,and 22020102006)Postdoctoral Fellowship Program of CPSF(GZB20240220)+2 种基金the Guangxi Department of Science and Technology(AA23062016)Natural Science Foundation of Shanghai(25ZR1402108)Fundamental Research Funds for the Central Universities.
文摘Bio-based organic room-temperature phosphorescence(RTP)materials have drawn considerable interest due to their potential to replace conventional petroleum-based RTP materials and attain comprehensive full life-cycle carbon reduction,a feat attributable to their renewable,biocompatible,and environmentally friendly characteristics.Bio-based organic RTP materials derived from natural biomass(e.g.,cellulose,lignin,chitosan)or biologically produced substances possess the capacity to spontaneously generate RTP or contribute to its generation.In this paper,the development lineage of bio-based RTP materials is introduced from the above two directions,including different systems,how to construct such systems,and the current progress.With strategies including hydrogen bonding networks,host—vip encapsulation,and polymeric matrices,it achieves RTP lifetimes up to seconds and full visible-band emission.It then explores the application scenarios that emerge from the natural advantages of these materials,including anti-counterfeiting and encryption,environmental monitoring,and bioimaging.Finally,it brieflydiscusses the potential challenges associated with bio-based RTP materials and envisions future development directions for them.While bio-based RTP materials rival petroleum-based counterparts in RTP efficiency,challenges persist:high production costs,poor environmental/thermal stability,and balancing degradability with durability.These sustainable alternatives offer biodegradability,renewability,and reduced lifecycle carbon emissions,utilizing agricultural byproducts(e.g.,corn stalks,shrimp shells)to enhance circular economies.
基金supported by the National Natural Science Foundation of China(No.22005201)the Young Scholars Science Foundation of Lanzhou Jiaotong University(No.2022023)the Fundamental Research Funds for the Central Universities,and the Youth Science and Technology Foundation of Gansu Province(Nos.22JR5RA541 and 22JR5RA374).
文摘Room-temperature sodium-sulfur(RT Na-S)batteries have been regarded as promising energy storage technologies in grid-scale stationary energy storage systems due to their low cost,natural abundance,and high-energy density.However,the practical application of RT Na-S batteries is hindered by low reversible capacity and unsatisfying long-cycling performance arising from the severe shuttle effect and sluggish S redox kinetics.This review provides an overview of recent efforts for the optimization strategies of the electronic structure of catalysts via catalyst engineering to enhance the adsorption and catalytic activity toward soluble long-chain sodium polysulfides(NaPSs).Finally,the current challenges and prospects for further optimization strategies of catalysts,understanding catalysis and structural evolution mechanism,and achieving practical applications are highlighted to meet the commercial requirements of RT Na-S batteries.
基金supported by the Key Program of the National Natural Science Foundation of China (No. 19934003)the Grand Program of Natural Science Research of Anhui Education Department (No. ZD2007003-1)the Natural Science Research Program of Universities and Colleges of Anhui Province, China (Nos. KJ2008A19ZC, KJ2009B281Z, and KJ2009A053Z)
文摘La0.5Sm0.2Sr0.3MnO3/（Ag2O）x/2 （x = 0.00, 0.04, 0.08, 0.25, 0.30） samples were prepared by the solid-state reaction method, and their transport behaviors, transport mechanism, and magnetoresistance effect were studied through the measurement and fitting of p-T curves. The results show that the element Ag takes part in reaction when the doping amount is small. Ag is mainly distributed at the grain boundary of the host material and is in metallic state when the doping amount is relatively large; then the system becomes a two-phase composite. A small amount of Ag doping can apparently increase grain-boundary magnetoresistance induced by the spin-dependent scattering. The resistivity of the sample doped with 30 mol% Ag is one order of magnitude smaller than that of low-doped samples, and its magnetoresistance in the magnetic field of 0.5 T and at 300 K is strengthened apparently reaching 9.4%, which is connected not only with the improvement of the grain-boundary structure of the host material but also with the decrease of material resistivity.
基金supported by the National Key Technologies R&D Program (Nos. 2016YFB1100102, 2018YFB1106003).
文摘Near-equiaxed β grain was achieved in the near-α Ti60(Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C) titanium alloy via laser directed energy deposition(LDED). The microstructural evolution along the building direction and the room-temperature tensile properties along the horizontal and vertical directions(building direction) were systematically studied through SEM and OM. EBSD and XRD were utilized to accurately demonstrate the texture of the α and β phases. The results showed that the α phase presented a low texture intensity, which was ascribed to the weak textured β grain with near-equiaxed morphology, since there are Burgers orientation relationships during the β →α transition. In addition, numerical simulation, combined with the CET curve of Ti60 alloy considering the effect of multi-composition,was utilized to elucidate the formation mechanism of the near-equiaxed β grains. Furthermore, according to the solidification theory, we proposed that the solidification temperature range ΔTfwas more accurate than the growth restriction factor Q in predicting the formation tendency of equiaxed β grain in different titanium alloys. Tensile results showed that the horizontal and vertical samples had similar strength,while the former exhibited larger elongation than the latter. The effect of the near-equiaxed β grain and the internal α phase on mechanical properties were revealed at last.
基金This research was supported by the Australian Research Council(ARC)(DE170100928,DP170101467)an Australian Renewable Energy Agency(ARENA)Project(G00849).The authors acknowledge the use of the facilities at the UOW Electron Microscopy Center(LE0882813 and LE0237478)and Dr.Tania Silver for critical reading of the manuscript.
文摘This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and status are investigated.A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio(72%S).In contrast,a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio(44%S).In carbonate ester electrolyte,only the sulfur trapped in porous structures is active via‘solid-solid’behavior during cycling.The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents.To improve the capacity of the sulfur-rich cathode,ether electrolyte with NaNO_(3) additive is explored to realize a‘solid-liquid’sulfur redox process and confine the shuttle effect of the dissolved polysulfides.As a result,the sulfur-rich cathode achieved high reversible capacity(483 mAh g^(−1)),corresponding to a specific energy of 362 Wh kg^(−1) after 200 cycles,shedding light on the use of ether electrolyte for high-loading sulfur cathode.
基金financially supported by the Singapore MOE AcRF Tier 2(Nos.2018-T2-1-010)Singapore A*STAR project(A19D9a0096 and SC25/21-102419)+3 种基金Singapore MOE Tier 1 RG128/21.Q.Zhu and A.Suwardi acknowledge Agency for Science,Technology and Research(A*STAR)Singapore Career Development Fund(CDF)(No.C210112022)the Sustainable Hybrid Lighting System for Controlled Environment Agriculture Program(No.A19D9a0096)support from S&T Program of Hebei(No.206Z4403G)。
文摘GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high carrier concentration.Here,we successfully enhance the Seebeck coefficient of GeTe from~30 to 220μV·K^(−1) at 300 K,which is achieved by AgInSe2 alloying and Bi doping.It is demonstrated that Bi doping helps to optimize the Seebeck coefficient without deteriorating the intrinsic electrical transport properties of the matrix.A high room-temperature power factor(PF)of~11μW·cm^(−1)·K^(−2) is achieved for a wide range of Bi-doped samples.The simultaneously introduced abundant point defects cause mass and strain fluctuations,which decrease the lattice thermal conductivity(κ_(L))to a low value of 0.6 W·m^(−1)·K^(−1) at 300 K.Due to the synergetic effects of Bi doping in AgInSe2-alloyed GeTe,a high room-temperature ZT value of 0.46 is obtained together with a high ZT value of 1.1 at 523 K.
基金This work was supported by the National Natural Science Foundation of China(52071137,51977071,51802040,and 21802020)the Science and Technology Innovation Program of Hunan Province(2021RC3066 and 2021RC3067)+1 种基金the Natural Science Foundation of Hunan Province(2020JJ3004 and 2020JJ4192)N.Zhang and X.Xie also acknowledge the financial support of the Fundamental Research Funds for the Central Universities.
文摘Low-temperature assembly of MXene nanosheets into three-dimensional(3D) robust aerogels addresses the crucial stability concern of the nano-building blocks during the fabrication process,which is of key importance for transforming the fascinating properties at the nanoscale into the macroscopic scale for practical applications.Herein,suitable cross-linking agents(amino-propyltriethoxysilane,Mn^(2+),Fe^(2+),Zn^(2+),and Co^(2+)) as interfacial mediators to engineer the interlayer interactions are reported to realize the graphene oxide(GO)-assisted assembly of Ti_(3)C_(2)T_(x) MXene aerogel at room temperature.This elaborate aerogel construction not only suppresses the oxidation degradation of Ti_(3)C_(2)T_(x) but also generates porous aerogels with a high Ti_(3)C_(2)T_(x) content(87 wt%) and robustness,thereby guaranteeing the functional accessibility of Ti_(3)C_(2)T_(x) nanosheets and operational reliability as integrated functional materials.In combination with a further sulfur modification,the Ti_(3)C_(2)T_(x) aerogel electrode shows promising electrochemical performances as the freestanding anode for sodium-ion storage.Even at an ultrahigh loading mass of 12.3 mg cm^(-2),a pronounced areal capacity of 1.26 mAh cm^(-2) at a current density of 0.1 A g^(-1) has been achieved,which is of practical significance.This work conceptually suggests a new way to exert the utmost surface functionalities of MXenes in 3D monolithic form and can be an inspiring scaffold to promote the application of MXenes in different areas.
基金the financial support from The National Basic Research Program of China(No.2014CB643802)Ministry of Science and Technology(No.2016YFB0401001)the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals
文摘Room-temperature phosphorescence（RTP） materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes.In this short review,recent progress on enhancement of RTP from purely organic materials is summarized.According to the mechanism of phosphorescence emission,two principles are discussed to construct efficient RTP materials：one is promoting intersystem crossing（ISC） efficiency by using aromatic carbonyl,heavyatom,or/and heterocycle/heteroatom containing compounds;the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states,including embedding phosphors into polymers and packing them tightly in crystals.With aforementioned strategies,RTP from purely organic materials was achieved both in fluid and rigid media.
基金supported by the Natural Science Foundation of Hubei Province for Distinguished Young Scholars (No. 2019CFA056)the Fundamental Research Funds for the Central Universities and Wuhan University and the Fundamental Research Funds for the Central Universities (No. 2042021kf0226)。
文摘Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL and ultralong RTP(to naked eyes ~14 s) are successfully achieved in CDs system. Encoding information and patterns fabricated by directly screen-printing method are invisible to eyes under natural light. Interestingly, clear and multicolor patterns with tunable FL and RTP emissions are identified under the 365 nm, 395 nm and 465 nm excitation and removal of them, indicating potential application of carbon dots with different FL and RTP outputs in the high-level photonic anti-counterfeiting field.
基金financially supported by the National Key R@D Program of China(Grants 2016YFB0100100,2016YFA0200200)the National Natural Science Foundation of China(Grant Nos.51872283,22075279,21805273,22005297,22005298)+7 种基金the Liao Ning Revitalization Talents Program(Grant XLYC1807153)the Natural Science Foundation of Liaoning ProvinceJoint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(Grant 20180510038)Dalian Innovation Support Plan for High Level Talents(2019RT09)the Dalian National Laboratory For Clean Energy(DNL),CASDNL Cooperation Fund,CAS(DNL180310,DNL180308,DNL201912,and DNL201915)DICP(DICP ZZBS201708,DICP ZZBS201802,DICP I2020032)the China Postdoctoral Science Foundation(2019M661141,2020M680995)。
文摘Synthesis and applications of three-dimensional(3 D)porous graphene frameworks(GFs)have attracted extensive interest owing to their intriguing advantages of high specific surface area,enriched porosity,excellent electrical conductivity,exceptional compressibility and processability.However,it is still challenging for economically viable,fast and scalable assembly of 3 D GFs at room-temperature.Herein,we reported a one-step scalable strategy for fast self-assembly of graphene oxide into 3 D macroscopically porous GFs,with assistance of polyoxometalates(POM)as functional cross-linker and hydrazine hydrate as reductant at room-temperature.The resulting 3 D interconnected macroporous POM-GFs uniformly decorated with ultrasmall POM nanoclusters were directly processed into binder-/additive-free film compact electrodes(1.68 g cm^(-3))with highly aligned,layer-stacked structure and electrically conductivity(622 S m-1)for high-performance supercapacitors,showing an impressive gravimetric capacitance of205 F g-1,volumetric capacitance of 334 F cm^(-3) at 1 mV s^(-1),and remarkable cycling stability with capacitance retention of 83%after 10,000 cycles,outperforming the most reported GFs.Further,the solid-state supercapacitors offered excellent gravimetric capacitance of 157 F g-1 exceptionally volumetric capacitance of 115 F cm^(-3) at 2 mV s^(-1) based on single electrode,and volumetric energy density of2.6 mWh cm^(-3).Therefore,this work will open novel opportunities to room-temperature fast assembly of 3 D porous graphene architectures for high-energy-density supercapacitors.
基金the financial support from the Instrument Developing Project of the Chinese Academy of Sciences (No. YJKYYQ20170009)the National Natural Science Foundation of China(NSFC Nos. 21722603 and 21871083)the Innovation Program of Shanghai Municipal Education Commission
文摘Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.
基金National Natural Science Foundation of China(No.52090041).
文摘Reducing the hot working temperature and high-temperature deformation resistance of titanium alloy to improve hot rolling and hot extrusion workability of products with thin walls and complex section shapes has always been an important topic in the field of titanium alloy processing.This paper proposed a strategy of adding Mo and Fe elements to simultaneously reduce the hot working temperature and high-temperature deformation resistance of Ti-6Al-4V alloy.The effects of Mo and Fe contents on the mi-crostructure,β transus temperature(Tp),and high-temperature flow stress(HFS)of Ti-6Al-4V-xMo-xFe(x=0-5)alloys were investigated.The results showed that adding Mo and Fe can substantially reduce the Tp and HFS of the alloy,and greatly improve its room-temperature strength.Compared with com-mercial Ti-6Al-4V samples,the T_(β) of Ti-6Al-4V-2Mo-2Fe and Ti-6Al-4V-3Mo-3Fe samples was decreased by 68-98 ℃,and the HFS at 800-900 ℃ was decreased by 37.8%-46.0%.Compared with hot-rolled Ti-6Al-4V samples,the room-temperature tensile strength of hot-rolled Ti-6Al-4V-2Mo-2Fe samples was increased by about 30%,while the elongation hardly decreased.The increased strength was mainly at-tributed to fine grain strengthening and solid solution strengthening.The hot workability and room-temperature strength of Ti-6Al-4V alloy can be significantly improved by adding 2-3 wt.%Mo and Fe simultaneously.
基金financially supported by the National Natural Science Foundation of China (NSFC, No. 22035001)
文摘Stabilizing triplet excited states is important for room temperature phosphorescence(RTP)materials to achieve multifunctional applications in humid environment.However,due to the lack of preparation strategies,the realization of RTP materials in water still faces challenges.Herein,a new design strategy was presented to achieve RTP in water by confining carbonized polymer dots(CPDs)in amino functional mesoporous silica(MSNs-NH_(2)).The as-prepared MSNs-CPDs aqueous dispersion exhibited blue afterglow,lasting more than 3 s to naked eyes.The triplet excited states were protected from non-radiative deactivation by the double-confinement effect including covalent bonding fixation and mesoporous structure confinement.The MSNs-CPDs inherited the structure of MSNs-NH_(2),so the stability of morphology and properties were superior to CPDs and even most of silica-based CPDs RTP materials.A water-related encryption technique demonstrated the promising application of MSNs-CPDs as smart materials in the field of information security.Besides,the possibility of potential application in ion detection was also explored.
基金supported by the National Natural Science Foundation of China(No.61102006)Natural Science Foundation of Shandong Province,China(Nos.ZR2015EM019 and ZR2014EL006)。
文摘Metal oxide semiconductors(MOS)-reduced graphene oxide(rGO)nanocomposites have attracted great attention for room-tempe rature gas sensing applications.The development of novel sensing materials is the key issue for the effective detection of ammoniagas at room temperature.In the present work,the novel reduced graphene oxide(rGO)-In2 O3 nanocubes hybrid materials have been prepared via a simple electrostatic self-assembly strategy.Characterization re sults exhibit that the intimate interfacial contact between In2 O3 nanocubes and the rGO sheets are achieved.Particularly,the as-prepared rGO/In2 O3 nanocomposites displayed high sensitivity,fast response and excellent selectivity towards ammonia(NH3)at room-temperature,which clearly uncovers the merit of structural design and rational integration with rGO sheets.The superior gas sensing performance of the rGO/In2 O3 nanocomposites can be attributed to the synergetic effects of rGO sheets and porous In2 O3 nanocubes.The reported synthesis offers a general approach to rGO/MOS-based semiconductor composites for room-temperature gas sensing applications.
基金supported by the National Natural Science Foundation of China(Nos.51631004 and 52130101)the Basic Construction Fund in Jilin Province Budget for 2019(No.2019C042-8).
文摘According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-biodegradable,thus they produce a mass of waste disposal and cause environmental pollution is-sue.For the purpose of transforming waste into wealth and reducing environmental pollution,nitrogen and sulfur co-doped carbon nanofiber/carbon black(N,S-CNF/CB)composite derived from the discarded cigarette filters is employed to modify glass fiber(GF)separator for the first time in this study.N,S-CNF improves binding ability towards sodium polysulfides(SPSs)by chemisorption.Non-polar CB limits the dissolution of SPSs in the liquid electrolyte by physisorption.The experiment and density functional theory calculation results indicate that a RT-Na/S battery with a N,S-CNF/CB+GF separator exhibits good cycling stability and rate performance.After 100 cycles at a low current rate of 0.1 C,a RT-Na/S battery with a sulfur mass fraction of 71%delivers a discharge capacity of 703 mAh g^(−1).In addition,at a high current rate of 0.5 C,a discharge capacity of 527 mAh g^(−1) is still maintained after 900 cycles with a very low capacity fading rate of 0.035%per cycle.
基金the financial support from the National Natural Science Foundation of China (Nos. 21788102, 22125803, 22020102006 and 21871083)Program of Shanghai Academic/Technology Research Leader (No. 20XD1421300)+2 种基金‘Shu Guang’ Project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (No. 19SG26)the Innovation Program of Shanghai Municipal Education Commission (No. 2017–01–07–00–02-E00010)the Fundamental Research Funds for the Central Universities.
文摘Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials.
基金We thank the financial support from the National Natural Science Foundation of China.(No.20172038)
文摘Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
