High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production meth...High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production method relies on repeated impregnation-carbonization and graphitization,and is plagued by lengthy preparation cycles and high energy consumption.Phase transition-assisted self-pressurized selfsintering technology can rapidly produce high-strength graphite materials,but the fracture strain of the graphite materials produced is poor.To solve this problem,this study used a two-step sintering method to uniformly introduce micro-nano pores into natural graphite-based bulk graphite,achieving improved fracture strain of the samples without reducing their density and mechanical properties.Using natural graphite powder,micron-diamond,and nano-diamond as raw materials,and by precisely controlling the staged pressure release process,the degree of diamond phase transition expansion was effectively regulated.The strain-to-failure of the graphite samples reached 1.2%,a 35%increase compared to samples produced by fullpressure sintering.Meanwhile,their flexural strength exceeded 110 MPa,and their density was over 1.9 g/cm^(3).The process therefore produced both a high strength and a high fracture strain.The interface evolution and toughening mechanism during the two-step sintering process were investigated.It is believed that the micro-nano pores formed have two roles:as stress concentrators they induce yielding by shear and as multi-crack propagation paths they significantly lengthen the crack propagation path.The two-step sintering phase transition strategy introduces pores and provides a new approach for increasing the fracture strain of brittle materials.展开更多
Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design...Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design that involves the encapsulation of CuNi alloy nanoparticles within mesoporous silicon carbide nanofibers (mSiC_(f)) to achieve efficient tandem conversion of furfural (FFA) into 2-(isopropoxymethyl)furan (IPF). The unique one-dimensional (1D) mesoporous structure of mSiC_(f), coupled with abundant oxygen-containing groups, offers a favorable surface microenvironment for the stabilization of bimetallic CuNi active sites. Through carefully optimizing metal to acid sites, we have developed a catalyst containing a total mass ratio of 20 % Cu and Ni, which exhibits a remarkable performance with complete FFA conversion and 92 % IPF selectivity in 4 h. In-depth mechanistic investigations have revealed that the superior activity of this catalyst is attributed to a tandem reaction mechanism. Initially, FFA is hydrogenated at the dual metal active sites to produce furfuryl alcohol (FOL) as an intermediate, which is subsequently etherified at the acid sites with suitable species and strengths on the mSiC_(f) supports. Additionally, the robust 1D mSiC_(f) framework effectively protects the metal sites from agglomeration, resulting in excellent reusability of the catalyst. This study underscores the potential of mesoporous silicon carbide-supported bimetallic active sites for achieving enhanced tandem catalytic functionality.展开更多
Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution react...Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution reaction(HER),especially under high current densities.This study proposes the implementation of a singleatom NiNC cocatalyst concurrently generating CO and releasing OH^(-)to neutralize H^(+)in the electrolyte,thereby simultaneously suppressing HER and promoting C–C coupling.By homogeneously mixing the NiNC cocatalyst with Cu nanoparticles(NPs),as opposed to a stratified configuration,a high ethylene Faradaic efficiency(FE)of 57%was achieved at 600 mA cm^(-2)in acidic media,along with a remarkable single-pass CO_(2)conversion efficiency of 52.4%.While rotating disk electrode tests and operando Raman spectroscopy attest to the restricted H^(+)diffusion and elevated local pH near the catalyst surface,in situ Infrared and differential electrochemical mass spectrometries corroborate the spillover of CO from the cocatalyst to neighboring Cu NPs for enhanced C–C coupling.This work offers new insights into the design and application principles of compositional eCO_(2)R catalysts for promoting multicarbon synthesis in acidic media at high current density.展开更多
Photocatalytic dual-functional reaction under visible light irradiation represents a sustainable development strategy.In detail,H2production coupled with benzylamine oxidation can remarkably lower the cost by replacin...Photocatalytic dual-functional reaction under visible light irradiation represents a sustainable development strategy.In detail,H2production coupled with benzylamine oxidation can remarkably lower the cost by replacing sacrificial agents.In this work,Cd S quantum dots(Cd S QDs)were successfully loaded onto the surface of a porphyrinic metal-organic framework(Pd-PCN-222)by the electrostatic selfassembly at room temperature.The consequent Pd-PCN-222/CdS heterojunction composites displayed superb photocatalytic activity under visible light irradiation,achieving a H2production and benzylamine oxidation rate of 5069 and 3717μmol g^(-1)h^(-1)with>99%selectivity in 3 h.There is no noticeable loss of catalytic capability during three successive runs.Mechanistic studies by in situ electron spin resonance and X-ray photoelectron spectroscopy disclosed that CdS QDs injected photoexcited electrons to Pd-PCN-222 and then Zr6clusters under visible-light irradiation,and thus Cd S QDs and Zr6clusters behave as the photocatalytic oxidation and reduction centers,respectively.展开更多
Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compoun...Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compound is facilely fabricated via one-pot electrostatic assembly of γ-PGA with cationic ethyl lauroyl arginate(ELA).The functionalized γ-PGA compound(γ-PGA-ELA)ethanol solution can facilely produce colorless and transparent coatings on various inorganic,metal,and polymeric substrates,especially for the lumen of slender catheters(length up to 2 m,and inner diameter down to 1 mm).The functionalized γ-PGA coating presents remarkable antibacterial efficacy in vitro and in vivo.In addition,the γ-PGA compound is used as antibacterial additives of polyolefin via melting extrusion,and the asprepared antibacterial polyolefin demonstrates advantageous antibacterial efficacy.More importantly,the functionalized γ-PGA coating exhibit good hemocompatibility,low cytotoxicity,and satisfactory histocompatibility.The as-proposed γ-PGA compound has a great potential to serve as a safe and multifunctional antibacterial candidate to combat biomedical devices-related infections.展开更多
Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential stra...Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential strategy is to design anchoring materials(AMs)to appropriately adsorb Li-S species.Herein,we propose a new three-procedure protocol,named InfoAd(Informative Adsorption)to evaluate the anchoring of Li_(2)S on two-dimensional(2D)materials and disclose the underlying importance of material features by combining high-throughput calculation workflow and machine learning(ML).In this paradigm,we calculate the anchoring of Li_(2)S on 12552D A_(x)B_(y)(B in the VIA/VIIA group)materials and pick out 44(un)reported nontoxic 2D binary A_(x)B_(y)AMs,in which the importance of the geometric features on the anchoring effect is revealed by ML for the first time.We develop a new Infograph model for crystals to accurately predict whether a material has a moderate binding with Li_(2)S and extend it to all 2D materials.Our InfoAd protocol elucidates the underlying structure-property relationship of Li_(2)S adsorption on 2D materials and provides a general research framework of adsorption-related materials for catalysis and energy/substance storage.展开更多
Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir...Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir（I）/Rh（I）–L complexes have been investigated by density functional theory method. Our calculations revealed that L with planar configuration shows the largest first hyperpolarizability value, which is 2.2 to 5.5 times larger than that of others. It is attributed to the single direction of intramolecular charge transfer. When metal ions were embedded in ligands, the first hyperpolarizability values of mono-and bimetal Ir/Rh（I）–L complexes were smaller than that of L, and that of bimetal Ir/Rh（I）–L complexes were smaller than the corresponding monometallic Ir/Rh（I）–L. This is caused by the intramolecular charge transfer from multiple directions as well as the amount of charge transfer. On the other hand, on increasing the number of metal ions, the charge transfer in the opposite direction cancels each other more obviously. Our work would provide some theoretical reference for the second-order NLO responses of mono-and bimetal complexes.展开更多
Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of h...Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of high-temperature treatments has introduced uncertainties regarding the compositions and microstructures of resulting derivatives.Additionally,complete carbonization has led to diminished yields of the produced carbon composites,significantly limiting their practical applications.Consequently,the exploration of pristine MOF-based EMW absorbers presents an intriguing yet challenging endeavor,primarily due to inherently low electrical conductivity.In this study,we showcase the utilization of structurally robust Zr-MOFs as scaffolds to build highly conductive Zr-MOF/PPy composites via an inner-outer dual-modification approach,which involves the production of conducting polypyrrole(PPy)both within the confined nanoporous channels and the external surface of Zr-MOFs via post-synthetic modification.The interconnection of confined PPy and surface-lined PPy together leads to a consecutive and extensive conducting network to the maximum extent.This therefore entails outstanding conductivity up to~14.3 S cm^(-1) in Zr-MOF/PPy composites,which is approximately 1-2 orders of magnitude higher than that for conductive MOF nanocomposites constructed from either inner or outer modification.Benefiting from the strong and tunable conduction loss,as well as the induced dielectric polarization originated from the porous structures and MOF-polymer interfaces,Zr-MOF/PPy exhibits excellent microwave attenuation capabilities and a tunable absorption frequency range.Specifically,with only 15 wt.%loading,the minimum reflection loss(RLmin)can reach up to-67.4 dB,accompanied by an effective absorption bandwidth(EAB)extending to 6.74 GHz.Furthermore,the microwave absorption characteristics can be tailored from the C-band to the Ku-band by adjusting the loading of PPy.This work provides valuable insights into the fabrication of conductive MOF composites by presenting a straightforward pathway to enhance and reg-ulate electrical conduction in MOF-based nanocomposites,thus paving a way to facilely fabricate pristine MOF-based microwave absorbers.展开更多
Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly im...Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly improved optoelectronic performance.In this work,we studied the effect of introducing halogen precursors on the structure of classical PbS nanocrystals(NCs)during the synthesis process and realized the preparation of PbS/Pb_(3)S_(2)X_(2) core/shell structure for the first time.The core/shell structure can effectively improve their optical properties.Furthermore,our approach enables the synthesis of Pb_(3)S_(2)Br_(2) that had not yet been reported.Our results not only provide valuable insights into the heterogeneous integration of PbYX and PbY materials to elevate material properties but also provide an effective method for further expanding the preparation of PbYX material systems.展开更多
Hydrogen,as a clean and versatile energy carrier,plays a vital role in the global transition toward carbon neutrality.Achieving a sustainable hydrogen economy requires safe,efficient,and cost‐effective technologies a...Hydrogen,as a clean and versatile energy carrier,plays a vital role in the global transition toward carbon neutrality.Achieving a sustainable hydrogen economy requires safe,efficient,and cost‐effective technologies across production,storage,transportation,and utilization.On the production side,electrolysis and solar‐driven photocatalysis are rapidly advancing toward industrial adoption,yet remain constrained by electrolysis efficiency,cost,and electrolyzer durability.For storage and transportation,lowering costs and energy consumption,improving system efficiency,and deploying safe,high‐capacity hydrogen storage and transportation solutions are key priorities.Regarding hydrogen utilization,particularly hydrogen fuel cells and hydrogen‐based power systems,require further enhancement in their durability,reliability,and integration flexibility to enable widespread deployment across sectors.Therefore,this review provides a comprehensive overview of green hydrogen technologies,emphasizing recent advances,key challenges,and industrial demonstrations.By integrating insights from electrochemical and photochemical production,solid‐state and liquid‐phase storage,and hydrogen end‐use pathways,we propose a roadmap toward the scalable deployment of green hydrogen infrastructure.Coordinated progress across these domains will position hydrogen as a cornerstone of a sustainable,secure,and decarbonized global energy solution.展开更多
Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice dist...Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.展开更多
In this work,a portable sensor based on ionic liquids-carboxylated carbon nanotubes/screen-printed carbon electrodes(IL-COOH-CNTs/SPCE)was constructed and coupled with machine learning for sensitive sulfamethoxazole(S...In this work,a portable sensor based on ionic liquids-carboxylated carbon nanotubes/screen-printed carbon electrodes(IL-COOH-CNTs/SPCE)was constructed and coupled with machine learning for sensitive sulfamethoxazole(SMZ)detection.The IL-COOH-CNTs/SPCE exhibited low impedance,a large effective surface area,and excellent stability.The sensor displayed a wide linear range from 1.04 to 233.00μmol/L,with a limit of detection(LOD)of 0.009μmol/L and a limit of quantification(LOQ)of 0.030μmol/L.The sensor coupled with least square support vector machine(LSSVM)achieved superior predictive performance than when coupled with artificial neural network(ANN).Furthermore,the recoveries for spiked food samples using this method showed no significant difference from those obtained using highperformance liquid chromatography(HPLC),confirming the high accuracy and practicality of the developed method.In summary,the IL-COOH-CNTs/SPCE sensor provides a reliable,portable,and efficient alternative for SMZ detection in aquatic and livestock products.展开更多
Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gas...Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.展开更多
SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu ca...SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu can promote the formation of non-magnetic grain boundaries in Sm-Fe-Ti system.The effect of Cu content on the grain boundary phase formation and magnetic properties in Sm(Fe_(0.8)Co_(0.2))_(11-x)TiCu_(x)(x=0-0.5)strips has been investigated.Sm(Fe_(0.8)Co_(0.2))_(10.8)TiCu_(0.2) strip exhibited a maximum Ms value of 1.07 T.Coercivity improved from 20.96 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(11)Ti strip to 165.92 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(10.5)TiCu_(0.5) strip.When Cu content increased from 0 to 0.5 at.%,Fe content of the grain boundary phase decreased from 43.8 to 12.6 at.%.Due to the good wettability of Cu,main 1:12 phase is well isolated and enveloped by(Sm,Cu)-rich grain boundary phase.Cu addition facilitates the formation of the continuous non-magnetic grain boundaries and reduces grain size of main 1:12 phase,contributing to coercivity improvement of the strips.展开更多
The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxya...The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.展开更多
Natural hydraulic lime(NHL) has garnered increasing attention for its sustainable and suitable performance in the field of historical building restoration. However, the prolonged hardening time and sluggish hydration ...Natural hydraulic lime(NHL) has garnered increasing attention for its sustainable and suitable performance in the field of historical building restoration. However, the prolonged hardening time and sluggish hydration rate of NHL infiuence the workability, strength development, and durability of construction structures in which it is used. In this study, nano-metakaolin(NMK) was applied as a highly reactive supplementary cementitious material(SCM) for NHL-based mortars to enhance their properties with various ratios. Meanwhile, the effects of NMK and its related enhancement mechanism on the physical properties and chemical structures of NHL composites were systematically investigated, mainly involving the modifications in their microstructure, chemical composition, and C-S-H structure. Results demonstrated that NMK-modified samples showed distinct and superior properties to pure NHL sample, such as shorter initial/final setting times(15.1%–49.1%, 27.1%–50.0%), and higher compactness(67.8%–81.4%, 38.1%–44.8%),lower shrinkage(25.0%–56.3%, 12.5%–25.0%), enhanced compressive strength(404.5%–546.0%, 180.8%–354.1%) and fiexural strength(227.5%–351.1%, 59.9%–125.7%) for both early and late curing times(7 and28 days). The inclusion of NMK not only acts as a fine filler, but also promotes NHL's hydrate rate by its super high pozzolanic activity, thus optimizing the pore structures and increasing the content and the average silicate chain length of hydration gel in NHL. Overall, this study can contribute to a deeper understanding of the enhancement mechanism of NMK on the physical properties and chemical structures of NHL from a meso/microscopic perspective, with a view to broadening NHL's potential applications.展开更多
The discovery and synthesis of colloidal quantum dots(QDs)were awarded the 2023 Nobel Prize in Chemistry.QDs,as a novel class of materials distinct from traditional molecular materials and bulk materials,have rapidly ...The discovery and synthesis of colloidal quantum dots(QDs)were awarded the 2023 Nobel Prize in Chemistry.QDs,as a novel class of materials distinct from traditional molecular materials and bulk materials,have rapidly emerged in the field of optoelectronic applications due to their unique size-,composition-,surface-,and process-dependent optoelectronic properties.More importantly,their ultra-high specific surface area allows for the application of various surface chemical engineering techniques to regulate and optimize their optoelectronic performance.Furthermore,three-dimensionally confined QDs can achieve nearly perfect photoluminescence quantum yields and extended hot carrier cooling times.Particularly,their ability to be colloidally synthesized and processed using industrially friendly solvents is driving transformative changes in the fields of electronics,photonics,and optoelectronics.展开更多
Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative ...Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative decay to compete with the serious non-radiative decay.However,the moderate electron-donating capacity of TPA seriously limits the selection of acceptor for constructing longwavelength TADF emitters with narrow bandgaps.To address this issue,in this work,the peripheral benzene of TPA was replaced with 1,4-benzodioxane and anisole to obtain two new electrondonating units N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-6-amine(TPADBO,−5.02 eV)and 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline(TPAMO,−5.00 eV),which possess much shallower highest occupied molecule orbital(HOMO)energy levels than the prototype TPA(−5.33 eV).Based on TPA and the modified TPA donor fragments,three TADF emitters were designed and synthesized,namely Py-TPA,Py-TPADBO and Py-TPAMO,with the same acceptor fragment 12-(2,6-diisopropylphenyl)pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline(Py).Among them,Py-TPAMO exhibits the highest photoluminescence quantum yield of 78.4%and the smallest singlet-triplet energy gap,which is because the introduction of anisole does not cause significant molecule deformation for the excited Py-TPAMO.And Py-TPAMO-based OLEDs successfully realize a maximum external quantum efficiency of 25.5%with the emission peak at 605 nm.This work provides a series of candidate of donor fragments for the development of efficient long-wavelength TADF emitters.展开更多
The photocatalytic production of hydrogen peroxide(H_(2)O_(2))via the oxygen reduction reaction(ORR)holds great significance in chemical engineering,agriculture,and national defense.However,the underlying influence of...The photocatalytic production of hydrogen peroxide(H_(2)O_(2))via the oxygen reduction reaction(ORR)holds great significance in chemical engineering,agriculture,and national defense.However,the underlying influence of interfacial charge dynamics on catalytic performance remains poorly understood due to limitations in conventional characterization techniques.In this study,we employ thiolate-protected gold-silver metal nanoclusters(MNCs)and nitrogen-doped carbon dot-modified nanoclusters(MNCs/N-CDs)as model systems to investigate ORR selectivity and charge dynamics under light irradiation.This catalyst design leverages the self-oxidation behavior of thiolate ligands and the intrinsic ORR selectivity of nanoclusters to establish a clean and well-defined photocatalytic system.By integrating time-resolved transient photovoltage(TPV)spectroscopy and operando transient potential scanning(TPS)test,we demonstrate that N-CDs promote the separation and storage of photoinduced charge carriers,as well as enhance oxygen adsorption and activation on the catalyst surface,thereby significantly improving H_(2)O_(2)production efficiency.These findings offer new mechanistic insights into the interplay between interfacial charge dynamics and photocatalytic performance,providing guidance for the rational design of advanced ORR catalysts.展开更多
Rational design of porous metal oxide films that serve as not only the scaffolds for light absorbers but also the transfer layer of photo generated charges is essential for fabricating highly efficient photoanodes for...Rational design of porous metal oxide films that serve as not only the scaffolds for light absorbers but also the transfer layer of photo generated charges is essential for fabricating highly efficient photoanodes for photoelectrochemical(PEC)hydrogen generation.In this work,w report a facile one-step pyrolysis method which can convert Zn-based MOF to porous ZnO(m-ZnO)with rough surface and abundant oxygen vacancies(O_(v)).When incorporating core-shell quantum dots(QDs)as the light absorbers,the obtained photoanodes(m-ZnO@QDs)achieved outstanding PEC performance for hydrogen generation,exhibiting 1.6 times and 5.8 times higher saturated photocurrent density(J_(sc))than thos of conventional TiO_(2)@QDs and ZnO@QDs photoanodes,respectively.Comprehensive optical and electrochemical measurements reveal tha the rough surface of m-ZnO can significantly improve the light-harvesting capacity of corresponding photoanodes through surface-enhanced light scattering.Moreover,the O_(v)in m-ZnO facilitate the interfacial transfer of photogenerated electrons.Our findings indicate that the MOF are valuable precursors for the preparation of porous films,offering a promising route to develop high-performance QDs-based PEC devices.展开更多
基金Natural Science Foundation of Shanghai(24ZR1400800)he Natural Science Foundation of China(U23A20685,52073058,91963204)+1 种基金the National Key R&D Program of China(2021YFB3701400)Shanghai Sailing Program(23YF1400200)。
文摘High-performance graphite materials have important roles in aerospace and nuclear reactor technologies because of their outstanding chemical stability and high-temperature performance.Their traditional production method relies on repeated impregnation-carbonization and graphitization,and is plagued by lengthy preparation cycles and high energy consumption.Phase transition-assisted self-pressurized selfsintering technology can rapidly produce high-strength graphite materials,but the fracture strain of the graphite materials produced is poor.To solve this problem,this study used a two-step sintering method to uniformly introduce micro-nano pores into natural graphite-based bulk graphite,achieving improved fracture strain of the samples without reducing their density and mechanical properties.Using natural graphite powder,micron-diamond,and nano-diamond as raw materials,and by precisely controlling the staged pressure release process,the degree of diamond phase transition expansion was effectively regulated.The strain-to-failure of the graphite samples reached 1.2%,a 35%increase compared to samples produced by fullpressure sintering.Meanwhile,their flexural strength exceeded 110 MPa,and their density was over 1.9 g/cm^(3).The process therefore produced both a high strength and a high fracture strain.The interface evolution and toughening mechanism during the two-step sintering process were investigated.It is believed that the micro-nano pores formed have two roles:as stress concentrators they induce yielding by shear and as multi-crack propagation paths they significantly lengthen the crack propagation path.The two-step sintering phase transition strategy introduces pores and provides a new approach for increasing the fracture strain of brittle materials.
基金supported by the National Natu-ral Science Foundation of China(Nos.52225204,52173233,and 52202085)the Innovation Program of Shanghai Municipal Edu-cation Commission(No.2021-01-07-00-03-E00109)+4 种基金Natural Sci-ence Foundation of Shanghai(No.23ZR1479200)the Shanghai Sci-entific and Technological Innovation Project(No.24520712800)“Shuguang Program”Supported by the Shanghai Education Devel-opment Foundation and Shanghai Municipal Education Commis-sion(No.20SG33)the Fundamental Research Funds for the Central Universities(No.2232024Y-01)the DHU Distinguished Young Professor Program(Nos.LZA2022001and LZB2023002).
文摘Mesoporous framework supported metal nanoparticle catalyst represents a promising material platform for creating multiple active sites that drive tandem reactions. In this study, we demonstrate a novel catalyst design that involves the encapsulation of CuNi alloy nanoparticles within mesoporous silicon carbide nanofibers (mSiC_(f)) to achieve efficient tandem conversion of furfural (FFA) into 2-(isopropoxymethyl)furan (IPF). The unique one-dimensional (1D) mesoporous structure of mSiC_(f), coupled with abundant oxygen-containing groups, offers a favorable surface microenvironment for the stabilization of bimetallic CuNi active sites. Through carefully optimizing metal to acid sites, we have developed a catalyst containing a total mass ratio of 20 % Cu and Ni, which exhibits a remarkable performance with complete FFA conversion and 92 % IPF selectivity in 4 h. In-depth mechanistic investigations have revealed that the superior activity of this catalyst is attributed to a tandem reaction mechanism. Initially, FFA is hydrogenated at the dual metal active sites to produce furfuryl alcohol (FOL) as an intermediate, which is subsequently etherified at the acid sites with suitable species and strengths on the mSiC_(f) supports. Additionally, the robust 1D mSiC_(f) framework effectively protects the metal sites from agglomeration, resulting in excellent reusability of the catalyst. This study underscores the potential of mesoporous silicon carbide-supported bimetallic active sites for achieving enhanced tandem catalytic functionality.
基金supported by the National Natural Science Foundation of China(No.22571222 and 22309125,)the Natural Science Foundation of Jiangsu Province(No.BK20220483,BK20211306,BK20220027,and BK20221239)+2 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB150010)the Six Talent Peaks Project in Jiangsu Province(No.TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘Electrocatalytic CO_(2)reduction(eCO_(2)R)in acidic electrolytes is propitious to enhance CO_(2)utilization,yet suffering from low current efficiency due to the rapid kinetics of the competing hydrogen evolution reaction(HER),especially under high current densities.This study proposes the implementation of a singleatom NiNC cocatalyst concurrently generating CO and releasing OH^(-)to neutralize H^(+)in the electrolyte,thereby simultaneously suppressing HER and promoting C–C coupling.By homogeneously mixing the NiNC cocatalyst with Cu nanoparticles(NPs),as opposed to a stratified configuration,a high ethylene Faradaic efficiency(FE)of 57%was achieved at 600 mA cm^(-2)in acidic media,along with a remarkable single-pass CO_(2)conversion efficiency of 52.4%.While rotating disk electrode tests and operando Raman spectroscopy attest to the restricted H^(+)diffusion and elevated local pH near the catalyst surface,in situ Infrared and differential electrochemical mass spectrometries corroborate the spillover of CO from the cocatalyst to neighboring Cu NPs for enhanced C–C coupling.This work offers new insights into the design and application principles of compositional eCO_(2)R catalysts for promoting multicarbon synthesis in acidic media at high current density.
基金support from the National Natural Science Foundation of China(Nos.21773314,21821003 and 21890382)the Guangdong Natural Science Funds for Distinguished Young Scholar(No.2019B151502017)。
文摘Photocatalytic dual-functional reaction under visible light irradiation represents a sustainable development strategy.In detail,H2production coupled with benzylamine oxidation can remarkably lower the cost by replacing sacrificial agents.In this work,Cd S quantum dots(Cd S QDs)were successfully loaded onto the surface of a porphyrinic metal-organic framework(Pd-PCN-222)by the electrostatic selfassembly at room temperature.The consequent Pd-PCN-222/CdS heterojunction composites displayed superb photocatalytic activity under visible light irradiation,achieving a H2production and benzylamine oxidation rate of 5069 and 3717μmol g^(-1)h^(-1)with>99%selectivity in 3 h.There is no noticeable loss of catalytic capability during three successive runs.Mechanistic studies by in situ electron spin resonance and X-ray photoelectron spectroscopy disclosed that CdS QDs injected photoexcited electrons to Pd-PCN-222 and then Zr6clusters under visible-light irradiation,and thus Cd S QDs and Zr6clusters behave as the photocatalytic oxidation and reduction centers,respectively.
基金financially supported by the National Natural Science Foundation of China(Nos.51973221 and 51873213)the Youth Innovation Promotion Association of CAS(No.2017269)+1 种基金the Major Science and Technology Innovation Project of Shandong Province(No.2019JZZY011105)the High-Tech Research&Development Program of CAS-WEGO Group。
文摘Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compound is facilely fabricated via one-pot electrostatic assembly of γ-PGA with cationic ethyl lauroyl arginate(ELA).The functionalized γ-PGA compound(γ-PGA-ELA)ethanol solution can facilely produce colorless and transparent coatings on various inorganic,metal,and polymeric substrates,especially for the lumen of slender catheters(length up to 2 m,and inner diameter down to 1 mm).The functionalized γ-PGA coating presents remarkable antibacterial efficacy in vitro and in vivo.In addition,the γ-PGA compound is used as antibacterial additives of polyolefin via melting extrusion,and the asprepared antibacterial polyolefin demonstrates advantageous antibacterial efficacy.More importantly,the functionalized γ-PGA coating exhibit good hemocompatibility,low cytotoxicity,and satisfactory histocompatibility.The as-proposed γ-PGA compound has a great potential to serve as a safe and multifunctional antibacterial candidate to combat biomedical devices-related infections.
基金supported by National key research and development program of China(2022YFA1503101)National Natural Science Foundation of China(22173067,22203058)+4 种基金Science and Technology Project of Jiangsu Province(BK20200873,BZ2020011)the Science and Technology Development Fund,Macao SAR(0052/2021/A)Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Lithium-sulfur(Li-S)batteries are notable for their high theoretical energy density,but the‘shuttle effect’and the limited conversion kinetics of Li-S species can downgrade their actual performance.An essential strategy is to design anchoring materials(AMs)to appropriately adsorb Li-S species.Herein,we propose a new three-procedure protocol,named InfoAd(Informative Adsorption)to evaluate the anchoring of Li_(2)S on two-dimensional(2D)materials and disclose the underlying importance of material features by combining high-throughput calculation workflow and machine learning(ML).In this paradigm,we calculate the anchoring of Li_(2)S on 12552D A_(x)B_(y)(B in the VIA/VIIA group)materials and pick out 44(un)reported nontoxic 2D binary A_(x)B_(y)AMs,in which the importance of the geometric features on the anchoring effect is revealed by ML for the first time.We develop a new Infograph model for crystals to accurately predict whether a material has a moderate binding with Li_(2)S and extend it to all 2D materials.Our InfoAd protocol elucidates the underlying structure-property relationship of Li_(2)S adsorption on 2D materials and provides a general research framework of adsorption-related materials for catalysis and energy/substance storage.
基金Supported by the National Natural Science Foundation of China(No.21173035)the “12th Five-Year” Science and Technology Research Project of the Education Department of Jilin Province([2016]494)
文摘Metal complexes with excellent nonlinear optical（NLO） properties have attracted considerable attention. The geometry structure, electronic spectra and NLO properties of 2,2？-bidipyrrins（L） and mono-and bimetal Ir（I）/Rh（I）–L complexes have been investigated by density functional theory method. Our calculations revealed that L with planar configuration shows the largest first hyperpolarizability value, which is 2.2 to 5.5 times larger than that of others. It is attributed to the single direction of intramolecular charge transfer. When metal ions were embedded in ligands, the first hyperpolarizability values of mono-and bimetal Ir/Rh（I）–L complexes were smaller than that of L, and that of bimetal Ir/Rh（I）–L complexes were smaller than the corresponding monometallic Ir/Rh（I）–L. This is caused by the intramolecular charge transfer from multiple directions as well as the amount of charge transfer. On the other hand, on increasing the number of metal ions, the charge transfer in the opposite direction cancels each other more obviously. Our work would provide some theoretical reference for the second-order NLO responses of mono-and bimetal complexes.
基金supported by the Fundamental Research Funds for the Central Universities(Nos.2232023D-01 and 2232023D-07)the Shanghai Science&Technology Committee(No.22ZR1403300)the National Natural Science Foundation of China(No.52372040).
文摘Metal-organic frameworks(MOFs)have attracted significant interest as self-templates and precursors for the synthesis of carbon-based composites aimed at electromagnetic wave(EMW)absorption.However,the utilization of high-temperature treatments has introduced uncertainties regarding the compositions and microstructures of resulting derivatives.Additionally,complete carbonization has led to diminished yields of the produced carbon composites,significantly limiting their practical applications.Consequently,the exploration of pristine MOF-based EMW absorbers presents an intriguing yet challenging endeavor,primarily due to inherently low electrical conductivity.In this study,we showcase the utilization of structurally robust Zr-MOFs as scaffolds to build highly conductive Zr-MOF/PPy composites via an inner-outer dual-modification approach,which involves the production of conducting polypyrrole(PPy)both within the confined nanoporous channels and the external surface of Zr-MOFs via post-synthetic modification.The interconnection of confined PPy and surface-lined PPy together leads to a consecutive and extensive conducting network to the maximum extent.This therefore entails outstanding conductivity up to~14.3 S cm^(-1) in Zr-MOF/PPy composites,which is approximately 1-2 orders of magnitude higher than that for conductive MOF nanocomposites constructed from either inner or outer modification.Benefiting from the strong and tunable conduction loss,as well as the induced dielectric polarization originated from the porous structures and MOF-polymer interfaces,Zr-MOF/PPy exhibits excellent microwave attenuation capabilities and a tunable absorption frequency range.Specifically,with only 15 wt.%loading,the minimum reflection loss(RLmin)can reach up to-67.4 dB,accompanied by an effective absorption bandwidth(EAB)extending to 6.74 GHz.Furthermore,the microwave absorption characteristics can be tailored from the C-band to the Ku-band by adjusting the loading of PPy.This work provides valuable insights into the fabrication of conductive MOF composites by presenting a straightforward pathway to enhance and reg-ulate electrical conduction in MOF-based nanocomposites,thus paving a way to facilely fabricate pristine MOF-based microwave absorbers.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0110300)the National Natural Science Foundation of China(Grant Nos.52372215,92163114,and 52202274)+5 种基金the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20230504)the Special Fund for the"Dual Carbon"Science and Technology Innovation of Jiangsu province(Industrial Prospect and Key Technology Research program)(Grant Nos.BE2022023 and BE2022021)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.21KJA430004)Gusu Innovation and Entre preneurship Leading Talent Program(Grant No.ZXL2022451)the China Postdoctoral Science Foundation(Grant No.2023M732523)supported by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project.
文摘Lead chalcohalides(PbYX,X=Cl,Br,I;Y=S,Se)is an extension of the classic Pb chalcogenides(PbY).Constructing the heterogeneous integration with PbYX and PbY material systems makes it possible to achieve significantly improved optoelectronic performance.In this work,we studied the effect of introducing halogen precursors on the structure of classical PbS nanocrystals(NCs)during the synthesis process and realized the preparation of PbS/Pb_(3)S_(2)X_(2) core/shell structure for the first time.The core/shell structure can effectively improve their optical properties.Furthermore,our approach enables the synthesis of Pb_(3)S_(2)Br_(2) that had not yet been reported.Our results not only provide valuable insights into the heterogeneous integration of PbYX and PbY materials to elevate material properties but also provide an effective method for further expanding the preparation of PbYX material systems.
基金supported by the National Key R&D Program of China(no.2022YFB3803700)the National Natural Science Foundation(52401386)the SINOPEC Research Institute of Petroleum Processing Co.Ltd.Fund(25H010102119).
文摘Hydrogen,as a clean and versatile energy carrier,plays a vital role in the global transition toward carbon neutrality.Achieving a sustainable hydrogen economy requires safe,efficient,and cost‐effective technologies across production,storage,transportation,and utilization.On the production side,electrolysis and solar‐driven photocatalysis are rapidly advancing toward industrial adoption,yet remain constrained by electrolysis efficiency,cost,and electrolyzer durability.For storage and transportation,lowering costs and energy consumption,improving system efficiency,and deploying safe,high‐capacity hydrogen storage and transportation solutions are key priorities.Regarding hydrogen utilization,particularly hydrogen fuel cells and hydrogen‐based power systems,require further enhancement in their durability,reliability,and integration flexibility to enable widespread deployment across sectors.Therefore,this review provides a comprehensive overview of green hydrogen technologies,emphasizing recent advances,key challenges,and industrial demonstrations.By integrating insights from electrochemical and photochemical production,solid‐state and liquid‐phase storage,and hydrogen end‐use pathways,we propose a roadmap toward the scalable deployment of green hydrogen infrastructure.Coordinated progress across these domains will position hydrogen as a cornerstone of a sustainable,secure,and decarbonized global energy solution.
文摘Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.
文摘In this work,a portable sensor based on ionic liquids-carboxylated carbon nanotubes/screen-printed carbon electrodes(IL-COOH-CNTs/SPCE)was constructed and coupled with machine learning for sensitive sulfamethoxazole(SMZ)detection.The IL-COOH-CNTs/SPCE exhibited low impedance,a large effective surface area,and excellent stability.The sensor displayed a wide linear range from 1.04 to 233.00μmol/L,with a limit of detection(LOD)of 0.009μmol/L and a limit of quantification(LOQ)of 0.030μmol/L.The sensor coupled with least square support vector machine(LSSVM)achieved superior predictive performance than when coupled with artificial neural network(ANN).Furthermore,the recoveries for spiked food samples using this method showed no significant difference from those obtained using highperformance liquid chromatography(HPLC),confirming the high accuracy and practicality of the developed method.In summary,the IL-COOH-CNTs/SPCE sensor provides a reliable,portable,and efficient alternative for SMZ detection in aquatic and livestock products.
基金funding support from the National Key Research and Development Program of China(No.2022YFB3805800)the National Natural Science Foundation of China(52173059)+1 种基金The Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJA540002)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB555).
文摘Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.
文摘SmFe_(12)-based alloys perform promising potential for new generation permanent magnets,attributed to their high saturation magnetization(Ms)and anisotropy field(Ha).Introduction of the low melting point element Cu can promote the formation of non-magnetic grain boundaries in Sm-Fe-Ti system.The effect of Cu content on the grain boundary phase formation and magnetic properties in Sm(Fe_(0.8)Co_(0.2))_(11-x)TiCu_(x)(x=0-0.5)strips has been investigated.Sm(Fe_(0.8)Co_(0.2))_(10.8)TiCu_(0.2) strip exhibited a maximum Ms value of 1.07 T.Coercivity improved from 20.96 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(11)Ti strip to 165.92 kA m^(-1) for Sm(Fe_(0.8)Co_(0.2))_(10.5)TiCu_(0.5) strip.When Cu content increased from 0 to 0.5 at.%,Fe content of the grain boundary phase decreased from 43.8 to 12.6 at.%.Due to the good wettability of Cu,main 1:12 phase is well isolated and enveloped by(Sm,Cu)-rich grain boundary phase.Cu addition facilitates the formation of the continuous non-magnetic grain boundaries and reduces grain size of main 1:12 phase,contributing to coercivity improvement of the strips.
基金financially supported by the National Natural Science Foundation of China(No.22101194)Natural Science Foundation of Jiangsu Province(No.BK20210733)+3 种基金Suzhou Municipal Science and Technology Bureau(No.ZXL2021447)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.
基金sponsored by National Key R&D Program of China (No. 2021YFC1523403)Guangxi Key Technologies R&D Program (No. AB22080102)+1 种基金Shanxi Provincial Cultural Relics Protection Science and Technology Program (No. 208141400241)Special Key Project of Chongqing Technology Innovation and Application Development (No. CSTB2022TIAD-KPX0095)。
文摘Natural hydraulic lime(NHL) has garnered increasing attention for its sustainable and suitable performance in the field of historical building restoration. However, the prolonged hardening time and sluggish hydration rate of NHL infiuence the workability, strength development, and durability of construction structures in which it is used. In this study, nano-metakaolin(NMK) was applied as a highly reactive supplementary cementitious material(SCM) for NHL-based mortars to enhance their properties with various ratios. Meanwhile, the effects of NMK and its related enhancement mechanism on the physical properties and chemical structures of NHL composites were systematically investigated, mainly involving the modifications in their microstructure, chemical composition, and C-S-H structure. Results demonstrated that NMK-modified samples showed distinct and superior properties to pure NHL sample, such as shorter initial/final setting times(15.1%–49.1%, 27.1%–50.0%), and higher compactness(67.8%–81.4%, 38.1%–44.8%),lower shrinkage(25.0%–56.3%, 12.5%–25.0%), enhanced compressive strength(404.5%–546.0%, 180.8%–354.1%) and fiexural strength(227.5%–351.1%, 59.9%–125.7%) for both early and late curing times(7 and28 days). The inclusion of NMK not only acts as a fine filler, but also promotes NHL's hydrate rate by its super high pozzolanic activity, thus optimizing the pore structures and increasing the content and the average silicate chain length of hydration gel in NHL. Overall, this study can contribute to a deeper understanding of the enhancement mechanism of NMK on the physical properties and chemical structures of NHL from a meso/microscopic perspective, with a view to broadening NHL's potential applications.
文摘The discovery and synthesis of colloidal quantum dots(QDs)were awarded the 2023 Nobel Prize in Chemistry.QDs,as a novel class of materials distinct from traditional molecular materials and bulk materials,have rapidly emerged in the field of optoelectronic applications due to their unique size-,composition-,surface-,and process-dependent optoelectronic properties.More importantly,their ultra-high specific surface area allows for the application of various surface chemical engineering techniques to regulate and optimize their optoelectronic performance.Furthermore,three-dimensionally confined QDs can achieve nearly perfect photoluminescence quantum yields and extended hot carrier cooling times.Particularly,their ability to be colloidally synthesized and processed using industrially friendly solvents is driving transformative changes in the fields of electronics,photonics,and optoelectronics.
基金supported by the National Natural Science Foundation of China (Nos. 62222503, 52073040 and 52130304)the Sichuan Science and Technology Program (Nos. 2024NSFSC0012,2023NSFSC1973 and 2024NSFSC1446)+2 种基金the China Postdoctoral Science Foundation (Nos. 2023M740504 and GZC20230380)the Sichuan Provincial Human Resources and Social Security Department Programthe Collaborative Innovation Center of Suzhou Nano Science&Technology
文摘Triphenylamine(TPA)is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence(TADF)emitters owing to its suitable dihedral angle that could enhance radiative decay to compete with the serious non-radiative decay.However,the moderate electron-donating capacity of TPA seriously limits the selection of acceptor for constructing longwavelength TADF emitters with narrow bandgaps.To address this issue,in this work,the peripheral benzene of TPA was replaced with 1,4-benzodioxane and anisole to obtain two new electrondonating units N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-6-amine(TPADBO,−5.02 eV)and 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline(TPAMO,−5.00 eV),which possess much shallower highest occupied molecule orbital(HOMO)energy levels than the prototype TPA(−5.33 eV).Based on TPA and the modified TPA donor fragments,three TADF emitters were designed and synthesized,namely Py-TPA,Py-TPADBO and Py-TPAMO,with the same acceptor fragment 12-(2,6-diisopropylphenyl)pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline(Py).Among them,Py-TPAMO exhibits the highest photoluminescence quantum yield of 78.4%and the smallest singlet-triplet energy gap,which is because the introduction of anisole does not cause significant molecule deformation for the excited Py-TPAMO.And Py-TPAMO-based OLEDs successfully realize a maximum external quantum efficiency of 25.5%with the emission peak at 605 nm.This work provides a series of candidate of donor fragments for the development of efficient long-wavelength TADF emitters.
基金supported by National Natural Science Foundation of China(42076193,52271223,52472049,52472230,52471234,52202107,52272043)Natural Science Foundation of Jiangsu Province(BK20220028,BK20230065)+5 种基金National Key R&D Program of China(2024YFA1509300)Ministry of Science and Technology of China(2024YFA1509500)State Key Laboratory of Catalysis(2024SKL-A-014)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectSuzhou Key Laboratory of Functional Nano&Soft Materials
文摘The photocatalytic production of hydrogen peroxide(H_(2)O_(2))via the oxygen reduction reaction(ORR)holds great significance in chemical engineering,agriculture,and national defense.However,the underlying influence of interfacial charge dynamics on catalytic performance remains poorly understood due to limitations in conventional characterization techniques.In this study,we employ thiolate-protected gold-silver metal nanoclusters(MNCs)and nitrogen-doped carbon dot-modified nanoclusters(MNCs/N-CDs)as model systems to investigate ORR selectivity and charge dynamics under light irradiation.This catalyst design leverages the self-oxidation behavior of thiolate ligands and the intrinsic ORR selectivity of nanoclusters to establish a clean and well-defined photocatalytic system.By integrating time-resolved transient photovoltage(TPV)spectroscopy and operando transient potential scanning(TPS)test,we demonstrate that N-CDs promote the separation and storage of photoinduced charge carriers,as well as enhance oxygen adsorption and activation on the catalyst surface,thereby significantly improving H_(2)O_(2)production efficiency.These findings offer new mechanistic insights into the interplay between interfacial charge dynamics and photocatalytic performance,providing guidance for the rational design of advanced ORR catalysts.
基金supported by the National Natural Science Foundation of China(Grant No.12275190,12105201)Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB723)。
文摘Rational design of porous metal oxide films that serve as not only the scaffolds for light absorbers but also the transfer layer of photo generated charges is essential for fabricating highly efficient photoanodes for photoelectrochemical(PEC)hydrogen generation.In this work,w report a facile one-step pyrolysis method which can convert Zn-based MOF to porous ZnO(m-ZnO)with rough surface and abundant oxygen vacancies(O_(v)).When incorporating core-shell quantum dots(QDs)as the light absorbers,the obtained photoanodes(m-ZnO@QDs)achieved outstanding PEC performance for hydrogen generation,exhibiting 1.6 times and 5.8 times higher saturated photocurrent density(J_(sc))than thos of conventional TiO_(2)@QDs and ZnO@QDs photoanodes,respectively.Comprehensive optical and electrochemical measurements reveal tha the rough surface of m-ZnO can significantly improve the light-harvesting capacity of corresponding photoanodes through surface-enhanced light scattering.Moreover,the O_(v)in m-ZnO facilitate the interfacial transfer of photogenerated electrons.Our findings indicate that the MOF are valuable precursors for the preparation of porous films,offering a promising route to develop high-performance QDs-based PEC devices.
