Electrochemical reduction of CO_(2)(CO_(2)RR)to form high-energy-density and high-value-added multicarbon products has attracted much attention.Selective reduction of CO_(2)to C^(2+)products face the problems of low r...Electrochemical reduction of CO_(2)(CO_(2)RR)to form high-energy-density and high-value-added multicarbon products has attracted much attention.Selective reduction of CO_(2)to C^(2+)products face the problems of low reaction rate,complex mechanism and low selectivity.Currently,except for a few examples,copper-based catalysts are the only option capable of achieving efficient generation of C^(2+)products.However,the continuous dynamic reconstruction of the catalyst causes great difficulty in understanding the structure-performance relationship of CO_(2)RR.In this review,we first discuss the mechanism of C^(2+)product generation.The structural factors promoting C^(2+)product generation are outlined,and the dynamic evolution of these structural factors is discussed.Furthermore,the effects of electrolyte and electrolysis conditions are reviewed in a vision of dynamic surface.Finally,further exploration of the reconstruction mechanism of Cu-based catalysts and the application of emerging robotic AI chemists are discussed.展开更多
Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult...Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.展开更多
1 Introduction Aromatics(mainly benzene,toluene,and xylenes,BTX)are essential intermediates in the chemical industry.They are employed in the synthesis of a broad spectrum of chemicals and materials,e.g.,various polym...1 Introduction Aromatics(mainly benzene,toluene,and xylenes,BTX)are essential intermediates in the chemical industry.They are employed in the synthesis of a broad spectrum of chemicals and materials,e.g.,various polymers,plastics,resins,solvents,dyes,pharmaceuticals^([1]).The manufacturing pathway of BTX mainly includes petroleum reforming of naphtha,coal-to-aromatics,methanol-to-aromatics^([2]).展开更多
The intricate multiscale architectures in natural structural building blocks provide many sources of inspiration for the designs of artificial biomaterials.In nature,the assembly of highly ordered molecular crystals a...The intricate multiscale architectures in natural structural building blocks provide many sources of inspiration for the designs of artificial biomaterials.In nature,the assembly of highly ordered molecular crystals and amorphous aggregates often derives from inter-and intra-molecular interactions of biomacromolecules,e.g.,proteinaceous materials.The structural biomaterials derived from the protein self-assembly behave with remarkable mechanical performance.However,there is still a grand challenge to mimic the mechanical properties of natural protein-based biomaterials in a rational design fashion to yield comparable man-made synthetic ensembles.In this review,a brief perspective on current challenges and advances in terms of bioinspired structural materials is presented.We outline a framework for mimicking protein self-assembly of natural building blocks across multiscale and highlight the critical role of synthetic biology and chemical modifications in material biosynthesis.Particularly,we focus on the design and promising applications of protein-based fibers,adhesives,dynamic hydrogels and engineered living materials,in which natural mechanical functions are effectively reproduced.展开更多
Asymmetric olefin isomerization has become a powerful tool for positional migration of C=C double bonds to afford valuable chiral olefins.However,the synthesis of optically active all-carbon quaternary stereocenters v...Asymmetric olefin isomerization has become a powerful tool for positional migration of C=C double bonds to afford valuable chiral olefins.However,the synthesis of optically active all-carbon quaternary stereocenters via this strategy is still rare.Herein,we report a cobaltcatalyzed desymmetric olefin isomerization to access 1-methylcyclohexenes bearingβ-quaternary stereocenters in a chemo-,site-,and stereoselective fashion.Preliminary mechanistic studies have revealed the Co-H insertion/β–Helimination reaction pathway and the origin of remote stereocontrol of all-carbon quaternary centers.The gram-scale synthesis and stereoretentive transformations of spirocyclic products demonstrate the synthetic utility of this reaction.展开更多
Adhesives have attracted a great deal of attention as an advanced modality in biomedical engineering because of their unique wound management behavior.However,it is a grand challenge for current adhesive systems to ac...Adhesives have attracted a great deal of attention as an advanced modality in biomedical engineering because of their unique wound management behavior.However,it is a grand challenge for current adhesive systems to achieve robust adhesion due to their tenuous interfacial bonding strength.Moreover,the absence of dynamic adaptability in conventional chemical adhesives restricts neoblasts around the wound from migrating to the site,resulting in an inferior tissue-regeneration effect.Herein,an extracellular matrix-derived biocomposite adhesive with robust adhesion and a real-time skin healing effect is well-engineered.Liquid–liquid phase separation is well-harnessed to drive the assembly of the biocomposite adhesive,with the active involvement of supramolecular interactions between chimeric protein and natural DNA,leading to a robustly reinforced adhesion performance.The bioadhesive exhibits outstanding adhesion and sealing behaviors,with a sheared adhesion strength of approximately 18 MPa,outperforming its reported counterparts.Moreover,the engineered bioderived components endow this adhesive material with biocompatibility and exceptional biological functions including the promotion of cell proliferation and migration,such that the use of this material eventually yields real-time in situ skin regeneration.This work opens up novel avenues for functionalized bioadhesive engineering and biomedical translations.展开更多
Co_(3)O_(4) is considered as one of promising cathode catalysts for lithium oxygen(Li-O_(2))batteries,which contains both tetrahedral Co^(2+)sites(Co^(2+)Td)and octahedral Co^(3+)sites(Co^(3+)Oh).It is important to re...Co_(3)O_(4) is considered as one of promising cathode catalysts for lithium oxygen(Li-O_(2))batteries,which contains both tetrahedral Co^(2+)sites(Co^(2+)Td)and octahedral Co^(3+)sites(Co^(3+)Oh).It is important to reveal the effect of optimal geometric configuration and oxidation state of cobalt ion in Co_(3)O_(4) to improve the performance of Li-O_(2) batteries.Herein,through regulating the synthesis process,Co^(2+)and Co^(3+)sites in Co_(3)O_(4) were replaced with Zn and Al atoms to form materials with a unique Co site.The Li-O_(2) batteries based on ZnCo_(2)O_(4) showed longer cycle life than that of CoAl_(2)O_(4),suggesting that in Co_(3)O_(4),the Co^(3+)Oh site is a relatively better geometric configuration than Co^(2+)Td site for Li-O_(2) batteries.Theoretical calculations revealed that Co^(3+)Oh sites provide higher catalysis activity,regulating the adsorption energy of the intermediate LiO_(2) and accelerating the kinetics of the reaction in batteries,which further leads to the change of the morphology of the discharge product and ultimately improves the electrochemical performance of the batteries.展开更多
The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D...The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by vip solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry measurements.Correspondingly,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule removal.In this study,we integrated vip-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.展开更多
Broadband near-infrared(NIR) light sources demonstrate great potential in quantitative food analysis, material identification,invasive brain imaging diagnosis, and real-time health monitoring fields, etc. [1–3]. Comp...Broadband near-infrared(NIR) light sources demonstrate great potential in quantitative food analysis, material identification,invasive brain imaging diagnosis, and real-time health monitoring fields, etc. [1–3]. Compared with competing technologies based on quantum dots and organic crystals, NIR-emitting phosphor converted light-emitting diodes(pc-LEDs) favor high spectral modulation and physicochemical stability [4].展开更多
Lignin,as the second largest renewable biomass resource in nature,has increasingly received significant interest for its potential to be transformed into valuable chemicals,potentially contributing to carbon neutralit...Lignin,as the second largest renewable biomass resource in nature,has increasingly received significant interest for its potential to be transformed into valuable chemicals,potentially contributing to carbon neutrality.Among different approaches,renewable electricity-driven biomass conversion holds great promise to substitute a petroleum resource-driven one,owing to its characteristics of environmental friendliness,high energy efficiency,and tunable reactivity.The challenges lie on the polymeric structure and complex functional groups in lignin,requiring the development of efficient electrocatalysts for lignin valorization with enhanced activity and selectivity toward targeted chemicals.In this Review,we focus on the advancement of electrocatalytic valorization of lignin,from monomers,to dimers and to raw lignin,toward various valueadded chemicals,with emphasis on catalyst design,reaction innovation,and mechanistic study.The general strategies for catalyst design are also summarized,offering insights into enhancing the activity and selectivity.Finally,challenges and perspectives for the electrocatalytic conversion of lignin are proposed.展开更多
Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cel...Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cells,which involves hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER).The activity of HER/HOR in alkaline electrolyte,however,exhibits a significantly lower magnitude(2–3 orders)compared to that observed in an acidic medium,which hinders the development of alkaline water electrolysis and alkaline membrane fuel cells.Therefore,comprehending the characteristics of HOR/HER activity in alkaline electrolytes and elucidating its underlyingmechanismis a prerequisite for the designof advanced electrocatalysts.Based on this background,this reviewwill briefly summarize the explanations and controversies about the basic HOR mechanism,including bifunctional mechanismand hydrogen binding energy theory.Moreover,the crucial affecting factors of theHOR kinetics,such as dband center theory,interfacial water recombination,alkali metal cations and electronic effects,are discussed.Thus,based on the above theories,the design principle,catalytic performance,and latest progress ofHOR electrocatalysts are summarized.An outlook and future research perspectives of advanced catalysts for hydrogen energy recycling are addressed.This reviewis helpful to understand the latest development ofHORmechanismand design cost-effective and high-performance HOR electrocatalysts towards the production of clean renewable energies.展开更多
Fe-N-C materials with atomically dispersed Fe–N_(4) sites could tolerate the poisoning of phosphate,is regarded as the most promising alternative to costly Pt-based catalysts for the oxygen reduction in high temperat...Fe-N-C materials with atomically dispersed Fe–N_(4) sites could tolerate the poisoning of phosphate,is regarded as the most promising alternative to costly Pt-based catalysts for the oxygen reduction in high temperature polymer electrolyte membrane fuel cells(HT-PEMFCs).However,they still face the critical issue of insufficient activity in phosphoric acid.Herein,we demonstrate a P-doping strategy to increase the activity of Fe-N-C catalyst via a feasible one-pot method.X-ray absorption spectroscopy and electron microscopy with atomic resolution indicated that the P atom is bonded with the N in Fe–N_(4) site through C atoms.The as prepared Fe-NCP catalyst shows a half-wave potential of 0.75 V(vs.reversible hydrogen electrode(RHE),0.1 M H_(3)PO_(4)),which is 60 and 40 mV higher than that of Fe-NC and commercial Pt/C catalysts,respectively.More importantly,the Fe-NCP catalyst could deliver a peak power density of 357 mW·cm^(−2)in a high temperature fuel cell(160℃),exceeding the non-noble-metal catalysts ever reported.The enhancement of activity is attributed to the increasing charge density and poisoning tolerance of Fe–N_(4) caused by neighboring P.This work not only promotes the practical application of Fe-N-C materials in HT-PEMFCs,but also provides a feasible P-doping method for regulating the structure of single atom site.展开更多
Ultraviolet light(UV)is an essential component of ambient light,but high dose UV would damage genome DNA.While semiconductors and soft materials have been employed to detect the UV,the complex process and the instrume...Ultraviolet light(UV)is an essential component of ambient light,but high dose UV would damage genome DNA.While semiconductors and soft materials have been employed to detect the UV,the complex process and the instrumental requirement have limited the application in daily life.In this study,taking advantage of sequence designability,a series of hydrogels with different gel-sol transition rates was constructed under the same UV intensity by introducing competing hybridization to tune the stability of the molecular network.Through estimating the transition time between each system under UV light irradiation,the intensity of UV could be roughly estimated,which provided a convenient method for the visual detection of UV.展开更多
Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and s...Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and shear-thinning properties.Despite this,the underlying mechanism for these polymer-like properties remains unexplored.This study investigates the origin of SNWs’unique behavior from three distinct perspectives.Utilizing single-molecule force spectroscopy,we quantitatively measure the persistence lengths of SNWs,which provide a measure of flexibility.In addition,we evaluate the macroscopic mechanical properties of SNW materials,including the strength of electrospun fibers and gelation in solutions.Finally,we apply molecular dynamics to simulate the behaviors of SNWs under elongating and rotating conditions.The three perspectives mentioned above in the study collectively provide evidence for the structure-activity relationship of nanomaterials:a freely rotated backbone results in a flexible SNW,which is inclined to bend and entangle to form gels in solutions.Conversely,a stiff backbone leads to a rigid SNW,which induces strong fibers.展开更多
Atomically dispersed catalysts(ADCs)have been diffusely researched for the development of advanced catalytic processes owing to their welldefined structure,high atomic utilization,and outstanding activity.Precisely de...Atomically dispersed catalysts(ADCs)have been diffusely researched for the development of advanced catalytic processes owing to their welldefined structure,high atomic utilization,and outstanding activity.Precisely decoding the intrinsic structures and coordination microenvironments of ADCs still confronts significant challenges.Overcoming these challenges is important for profound understanding of the structure-activity relationships and directing the future design of ADCs.Herein,this minireview summarizes recent progress and advanced characterization techniques for the engineering of ADCs,including single-atom catalysts,dualatom catalysts,and atomic cluster catalysts with regard to precise synthesis,structural regulation,and the structure-performance relationship.The catalytic merits and regulation strategies of recent breakthroughs in energy conversion,enzyme mimicry,and organic synthesis are thoroughly discussed to disclose the catalytic mechanism-guided ADCs design.Finally,a comprehensive summary of the future challenges and potential prospects is presented to stimulate more design and application possibilities for ADCs.We believe that this comprehensive minireview will open up novel pathways for the widespread utilization of ADCs in diverse catalytic processes.展开更多
Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Ove...Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Over the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider silks.These strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse applications.Herein,we summarize the hosts that have been applied to produce recombinant spidroins.In addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also introduced.Furthermore,we demonstrate the applications of recombinant spidroin-based fibers.Finally,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.展开更多
Flexible inorganic double helical semiconductors similar to DNA have fueled the demand for efficient materials with innovative structures and excellent properties.The recent discovery of tin phosphide iodide(SnIP),the...Flexible inorganic double helical semiconductors similar to DNA have fueled the demand for efficient materials with innovative structures and excellent properties.The recent discovery of tin phosphide iodide(SnIP),the first carbon-free double helical semiconductor at an atomic level,has opened new avenues of research for semiconducting devices such as thermoelectric and sensor devices,solar cells,and photocatalysis.It has drawn significant academic attention due to its high structural flexibility,band gap in the visible spectrum range,and non-toxic elements.Herein,the recent progress in developing SnIP,including its prestigious structure,versatile and intriguing properties,and synthesis,is summarized.Other analogues of SnIP and SnIP-based hybrid materials and their applications in photocatalysis are also discussed.Finally,the review concludes with a critical summary and future aspects of this new inorganic semiconductor.展开更多
The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biol...The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biological detecting,remote sensing,and depth tracking due to their small sizes,sensitive properties of their spectral fingerprints,and flexible positional modulation in the microenvironment.Lanthanide-based luminescent materials that possess long excited-state lifetime,narrow emission bandwidth,and upconversion behaviors are promising as gain mediums for novel microlasers.In addition,lanthanide-based microlasers could be generated under natural ambient conditions with pumped or continuous light sources,which significantly promotes the practical applications of microlasers.Recent progress in the design,synthesis,and biomedical applications of lanthanide-based microlasers has been outlined in this review.Lanthanide ions doped and upconverted lanthanide-based microlasers are highlighted,which exhibit advantageous structures,miniaturized dimensions,and high lasing performance.The applications of lanthanide-based microlasers are further discussed,the upconverted microlasers show great advantages for biological applications owing to their tunable excitation and emission characteristics and excellent environmental stability.Moreover,perspectives and challenges in the field of lanthanide-based microlasers are presented.展开更多
The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air batteries.One promising way is to develop Fe single-atom catalysts.H...The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air batteries.One promising way is to develop Fe single-atom catalysts.However,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR intermediates.Herein,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was constructed.Various characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast kinetics.Consequently,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V vs.reversible hydrogen electrode(RHE),outperforming its counterparts in the references.Furthermore,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent stability.This work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.展开更多
文摘Electrochemical reduction of CO_(2)(CO_(2)RR)to form high-energy-density and high-value-added multicarbon products has attracted much attention.Selective reduction of CO_(2)to C^(2+)products face the problems of low reaction rate,complex mechanism and low selectivity.Currently,except for a few examples,copper-based catalysts are the only option capable of achieving efficient generation of C^(2+)products.However,the continuous dynamic reconstruction of the catalyst causes great difficulty in understanding the structure-performance relationship of CO_(2)RR.In this review,we first discuss the mechanism of C^(2+)product generation.The structural factors promoting C^(2+)product generation are outlined,and the dynamic evolution of these structural factors is discussed.Furthermore,the effects of electrolyte and electrolysis conditions are reviewed in a vision of dynamic surface.Finally,further exploration of the reconstruction mechanism of Cu-based catalysts and the application of emerging robotic AI chemists are discussed.
基金This work was supported by National Key R&D Program of China(2021YFF0500503)National Natural Science Foundation of China(21925202,U22B2071)International Joint Mission on Climate Change and Carbon Neutrality.
文摘Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.
基金the support from Tsinghua University and China Petroleumthe support from the academician workstation of Petrochemical Research Institute,China Petroleum。
文摘1 Introduction Aromatics(mainly benzene,toluene,and xylenes,BTX)are essential intermediates in the chemical industry.They are employed in the synthesis of a broad spectrum of chemicals and materials,e.g.,various polymers,plastics,resins,solvents,dyes,pharmaceuticals^([1]).The manufacturing pathway of BTX mainly includes petroleum reforming of naphtha,coal-to-aromatics,methanol-to-aromatics^([2]).
基金supported by the National Key R&D Program of China (No.2021YFB3502300)the National Natural Science Foundation of China (Nos.22125701,22020102003,22277064)+1 种基金the Beijing Nova Program,China (No.Z211100002121132)the Beijing Natural Science Foundation,China (No.2222010).
文摘The intricate multiscale architectures in natural structural building blocks provide many sources of inspiration for the designs of artificial biomaterials.In nature,the assembly of highly ordered molecular crystals and amorphous aggregates often derives from inter-and intra-molecular interactions of biomacromolecules,e.g.,proteinaceous materials.The structural biomaterials derived from the protein self-assembly behave with remarkable mechanical performance.However,there is still a grand challenge to mimic the mechanical properties of natural protein-based biomaterials in a rational design fashion to yield comparable man-made synthetic ensembles.In this review,a brief perspective on current challenges and advances in terms of bioinspired structural materials is presented.We outline a framework for mimicking protein self-assembly of natural building blocks across multiscale and highlight the critical role of synthetic biology and chemical modifications in material biosynthesis.Particularly,we focus on the design and promising applications of protein-based fibers,adhesives,dynamic hydrogels and engineered living materials,in which natural mechanical functions are effectively reproduced.
基金We gratefully acknowledge funding from the National Key R&D Program of China(grant no.2021YFF0701600)the National Natural Science Foundation of China(grant nos.22171159 and 22225103).
文摘Asymmetric olefin isomerization has become a powerful tool for positional migration of C=C double bonds to afford valuable chiral olefins.However,the synthesis of optically active all-carbon quaternary stereocenters via this strategy is still rare.Herein,we report a cobaltcatalyzed desymmetric olefin isomerization to access 1-methylcyclohexenes bearingβ-quaternary stereocenters in a chemo-,site-,and stereoselective fashion.Preliminary mechanistic studies have revealed the Co-H insertion/β–Helimination reaction pathway and the origin of remote stereocontrol of all-carbon quaternary centers.The gram-scale synthesis and stereoretentive transformations of spirocyclic products demonstrate the synthetic utility of this reaction.
基金supported by the National Key Research and Development Program of China(2022YFA0913200 and 2021YFB3502300)the National Natural Science Foundation of China(22020102003,22125701,22277064,82272161,52222214,and 22107097)+3 种基金Beijing Municipal Science and Technology Commission(221100007422088)Beijing Nova Program(Z211100002121132)Beijing Natural Science Foundation(2222010)Xiangfu Lab Research Project(XF012022C0200)。
文摘Adhesives have attracted a great deal of attention as an advanced modality in biomedical engineering because of their unique wound management behavior.However,it is a grand challenge for current adhesive systems to achieve robust adhesion due to their tenuous interfacial bonding strength.Moreover,the absence of dynamic adaptability in conventional chemical adhesives restricts neoblasts around the wound from migrating to the site,resulting in an inferior tissue-regeneration effect.Herein,an extracellular matrix-derived biocomposite adhesive with robust adhesion and a real-time skin healing effect is well-engineered.Liquid–liquid phase separation is well-harnessed to drive the assembly of the biocomposite adhesive,with the active involvement of supramolecular interactions between chimeric protein and natural DNA,leading to a robustly reinforced adhesion performance.The bioadhesive exhibits outstanding adhesion and sealing behaviors,with a sheared adhesion strength of approximately 18 MPa,outperforming its reported counterparts.Moreover,the engineered bioderived components endow this adhesive material with biocompatibility and exceptional biological functions including the promotion of cell proliferation and migration,such that the use of this material eventually yields real-time in situ skin regeneration.This work opens up novel avenues for functionalized bioadhesive engineering and biomedical translations.
基金supported by the National Key R&D Program of China(No.2021YFF0500503)the National Natural Science Foundation of China(Nos.21925202 and U22B2071).
文摘Co_(3)O_(4) is considered as one of promising cathode catalysts for lithium oxygen(Li-O_(2))batteries,which contains both tetrahedral Co^(2+)sites(Co^(2+)Td)and octahedral Co^(3+)sites(Co^(3+)Oh).It is important to reveal the effect of optimal geometric configuration and oxidation state of cobalt ion in Co_(3)O_(4) to improve the performance of Li-O_(2) batteries.Herein,through regulating the synthesis process,Co^(2+)and Co^(3+)sites in Co_(3)O_(4) were replaced with Zn and Al atoms to form materials with a unique Co site.The Li-O_(2) batteries based on ZnCo_(2)O_(4) showed longer cycle life than that of CoAl_(2)O_(4),suggesting that in Co_(3)O_(4),the Co^(3+)Oh site is a relatively better geometric configuration than Co^(2+)Td site for Li-O_(2) batteries.Theoretical calculations revealed that Co^(3+)Oh sites provide higher catalysis activity,regulating the adsorption energy of the intermediate LiO_(2) and accelerating the kinetics of the reaction in batteries,which further leads to the change of the morphology of the discharge product and ultimately improves the electrochemical performance of the batteries.
基金supported by the National Natural Science Foundation of China(22271171,21971142,and 22371015)Japan Society for Promotion Science(JSPS)KAKENHI(24K17698 and 24H00466)。
文摘The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching devices.Herein,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by vip solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry measurements.Correspondingly,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule removal.In this study,we integrated vip-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.
文摘Broadband near-infrared(NIR) light sources demonstrate great potential in quantitative food analysis, material identification,invasive brain imaging diagnosis, and real-time health monitoring fields, etc. [1–3]. Compared with competing technologies based on quantum dots and organic crystals, NIR-emitting phosphor converted light-emitting diodes(pc-LEDs) favor high spectral modulation and physicochemical stability [4].
基金supported by the National Key R&D Program of China(2023YFA1507400)the Haihe Laboratory of Sustainable Chemical Transformations,the National Natural Science Foundation of China(Grant No.22325805,21935001)Beijing Natural Science Foundation(JQ22003).
文摘Lignin,as the second largest renewable biomass resource in nature,has increasingly received significant interest for its potential to be transformed into valuable chemicals,potentially contributing to carbon neutrality.Among different approaches,renewable electricity-driven biomass conversion holds great promise to substitute a petroleum resource-driven one,owing to its characteristics of environmental friendliness,high energy efficiency,and tunable reactivity.The challenges lie on the polymeric structure and complex functional groups in lignin,requiring the development of efficient electrocatalysts for lignin valorization with enhanced activity and selectivity toward targeted chemicals.In this Review,we focus on the advancement of electrocatalytic valorization of lignin,from monomers,to dimers and to raw lignin,toward various valueadded chemicals,with emphasis on catalyst design,reaction innovation,and mechanistic study.The general strategies for catalyst design are also summarized,offering insights into enhancing the activity and selectivity.Finally,challenges and perspectives for the electrocatalytic conversion of lignin are proposed.
基金supported by the National Natural Science Foundation of China(22234005 and 21974070)the Natural Science Foundation of Jiangsu Province(BK20222015)Young Academic Leaders of the Qing Lan Project of Jiangsu Province(SUJIAOSHIHAN[2022]No.29).
文摘Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cells,which involves hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER).The activity of HER/HOR in alkaline electrolyte,however,exhibits a significantly lower magnitude(2–3 orders)compared to that observed in an acidic medium,which hinders the development of alkaline water electrolysis and alkaline membrane fuel cells.Therefore,comprehending the characteristics of HOR/HER activity in alkaline electrolytes and elucidating its underlyingmechanismis a prerequisite for the designof advanced electrocatalysts.Based on this background,this reviewwill briefly summarize the explanations and controversies about the basic HOR mechanism,including bifunctional mechanismand hydrogen binding energy theory.Moreover,the crucial affecting factors of theHOR kinetics,such as dband center theory,interfacial water recombination,alkali metal cations and electronic effects,are discussed.Thus,based on the above theories,the design principle,catalytic performance,and latest progress ofHOR electrocatalysts are summarized.An outlook and future research perspectives of advanced catalysts for hydrogen energy recycling are addressed.This reviewis helpful to understand the latest development ofHORmechanismand design cost-effective and high-performance HOR electrocatalysts towards the production of clean renewable energies.
基金the National Key Research and Development Program of China(No.2018YFA0702002)the Beijing Natural Science Foundation(No.Z210016)the National Natural Science Foundation of China(No.21935001)。
文摘Fe-N-C materials with atomically dispersed Fe–N_(4) sites could tolerate the poisoning of phosphate,is regarded as the most promising alternative to costly Pt-based catalysts for the oxygen reduction in high temperature polymer electrolyte membrane fuel cells(HT-PEMFCs).However,they still face the critical issue of insufficient activity in phosphoric acid.Herein,we demonstrate a P-doping strategy to increase the activity of Fe-N-C catalyst via a feasible one-pot method.X-ray absorption spectroscopy and electron microscopy with atomic resolution indicated that the P atom is bonded with the N in Fe–N_(4) site through C atoms.The as prepared Fe-NCP catalyst shows a half-wave potential of 0.75 V(vs.reversible hydrogen electrode(RHE),0.1 M H_(3)PO_(4)),which is 60 and 40 mV higher than that of Fe-NC and commercial Pt/C catalysts,respectively.More importantly,the Fe-NCP catalyst could deliver a peak power density of 357 mW·cm^(−2)in a high temperature fuel cell(160℃),exceeding the non-noble-metal catalysts ever reported.The enhancement of activity is attributed to the increasing charge density and poisoning tolerance of Fe–N_(4) caused by neighboring P.This work not only promotes the practical application of Fe-N-C materials in HT-PEMFCs,but also provides a feasible P-doping method for regulating the structure of single atom site.
基金supported by the Natural Science Foundation of Beijing Municipality,China (No.Z180016)the National Natural Science Foundation of China (No.21971248).
文摘Ultraviolet light(UV)is an essential component of ambient light,but high dose UV would damage genome DNA.While semiconductors and soft materials have been employed to detect the UV,the complex process and the instrumental requirement have limited the application in daily life.In this study,taking advantage of sequence designability,a series of hydrogels with different gel-sol transition rates was constructed under the same UV intensity by introducing competing hybridization to tune the stability of the molecular network.Through estimating the transition time between each system under UV light irradiation,the intensity of UV could be roughly estimated,which provided a convenient method for the visual detection of UV.
基金supported by the National Key R&D Program of China(grant no.2017YFA0700101)NSFC(grant nos.22241502,22035004,and 92261118)+1 种基金Young Elite Scientist Sponsorship Program by CAST(grant no.2022QNRC001)the XPLORER PRIZE.
文摘Sub-nanowires(SNWs),∼1 nm in thickness,possess an inorganic skeleton but display characteristics akin to those of carbon–carbon backbone polymers,such as flexibility,adhesion,gelation,self-assembling behaviors,and shear-thinning properties.Despite this,the underlying mechanism for these polymer-like properties remains unexplored.This study investigates the origin of SNWs’unique behavior from three distinct perspectives.Utilizing single-molecule force spectroscopy,we quantitatively measure the persistence lengths of SNWs,which provide a measure of flexibility.In addition,we evaluate the macroscopic mechanical properties of SNW materials,including the strength of electrospun fibers and gelation in solutions.Finally,we apply molecular dynamics to simulate the behaviors of SNWs under elongating and rotating conditions.The three perspectives mentioned above in the study collectively provide evidence for the structure-activity relationship of nanomaterials:a freely rotated backbone results in a flexible SNW,which is inclined to bend and entangle to form gels in solutions.Conversely,a stiff backbone leads to a rigid SNW,which induces strong fibers.
基金supported by the National Natural Science Foundation of China(grant no.22171157).
文摘Atomically dispersed catalysts(ADCs)have been diffusely researched for the development of advanced catalytic processes owing to their welldefined structure,high atomic utilization,and outstanding activity.Precisely decoding the intrinsic structures and coordination microenvironments of ADCs still confronts significant challenges.Overcoming these challenges is important for profound understanding of the structure-activity relationships and directing the future design of ADCs.Herein,this minireview summarizes recent progress and advanced characterization techniques for the engineering of ADCs,including single-atom catalysts,dualatom catalysts,and atomic cluster catalysts with regard to precise synthesis,structural regulation,and the structure-performance relationship.The catalytic merits and regulation strategies of recent breakthroughs in energy conversion,enzyme mimicry,and organic synthesis are thoroughly discussed to disclose the catalytic mechanism-guided ADCs design.Finally,a comprehensive summary of the future challenges and potential prospects is presented to stimulate more design and application possibilities for ADCs.We believe that this comprehensive minireview will open up novel pathways for the widespread utilization of ADCs in diverse catalytic processes.
基金supported by the National Key R&D Program of China(No.2022YFA0913200)the National Natural Science Foundation of China(Nos.22107097,22020102003,22125701,22175053,and 21771050)the Youth Innovation Promotion Association of CAS(No.2021226).
文摘Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Over the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider silks.These strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse applications.Herein,we summarize the hosts that have been applied to produce recombinant spidroins.In addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also introduced.Furthermore,we demonstrate the applications of recombinant spidroin-based fibers.Finally,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.
基金supported by the National Natural Science Foundation of China(No.52072198).
文摘Flexible inorganic double helical semiconductors similar to DNA have fueled the demand for efficient materials with innovative structures and excellent properties.The recent discovery of tin phosphide iodide(SnIP),the first carbon-free double helical semiconductor at an atomic level,has opened new avenues of research for semiconducting devices such as thermoelectric and sensor devices,solar cells,and photocatalysis.It has drawn significant academic attention due to its high structural flexibility,band gap in the visible spectrum range,and non-toxic elements.Herein,the recent progress in developing SnIP,including its prestigious structure,versatile and intriguing properties,and synthesis,is summarized.Other analogues of SnIP and SnIP-based hybrid materials and their applications in photocatalysis are also discussed.Finally,the review concludes with a critical summary and future aspects of this new inorganic semiconductor.
基金supported by Beijing Natural Science Foundation(2222010)the National Key Research and Development Program of China(2022YFF0710000 and 2021YFB3502300)+2 种基金the National Natural Science Foundation of China(52372274,52222214,22020102003,22388101,22125701,and 22361132542)the Natural Science Foundation of Jilin Province(20210101366JC)Tsinghua University Initiative Scientific Research Program。
基金supported by the National Natural Science Foundation of China(Nos.22020102003,22207104,and 22125701)the National Key R&D Program of China(Nos.2022YFF071000 and 2021YFF0701800)+2 种基金Natural Science Foundation of Jilin Province(No.20230101102JC)China Postdoctoral Science Foundation(Nos.2020M681055 and 2022T150634)Young Elite Scientists Sponsorship Program by CAST(Nos.2021-2023QNRC and YESS20210067).
文摘The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biological detecting,remote sensing,and depth tracking due to their small sizes,sensitive properties of their spectral fingerprints,and flexible positional modulation in the microenvironment.Lanthanide-based luminescent materials that possess long excited-state lifetime,narrow emission bandwidth,and upconversion behaviors are promising as gain mediums for novel microlasers.In addition,lanthanide-based microlasers could be generated under natural ambient conditions with pumped or continuous light sources,which significantly promotes the practical applications of microlasers.Recent progress in the design,synthesis,and biomedical applications of lanthanide-based microlasers has been outlined in this review.Lanthanide ions doped and upconverted lanthanide-based microlasers are highlighted,which exhibit advantageous structures,miniaturized dimensions,and high lasing performance.The applications of lanthanide-based microlasers are further discussed,the upconverted microlasers show great advantages for biological applications owing to their tunable excitation and emission characteristics and excellent environmental stability.Moreover,perspectives and challenges in the field of lanthanide-based microlasers are presented.
基金National Natural Science Foundation of China(No.51902013).
文摘The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air batteries.One promising way is to develop Fe single-atom catalysts.However,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR intermediates.Herein,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was constructed.Various characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast kinetics.Consequently,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V vs.reversible hydrogen electrode(RHE),outperforming its counterparts in the references.Furthermore,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent stability.This work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.
