Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The appro...Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.展开更多
Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hyd...Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.展开更多
Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor pol...Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor polymers, poly[4,8-bis（5-（2-ethylhexyl）thiophen-2-yl）benzo[ 1,2-b;4,5-b＇]dithiophene-2,6-diyl-alt-（4-（2-ethylhexyl）-3-fluorothieno[3,4- b]thiophene）-2-carboxylate-2,6-diyl] （PTB7-Th） and poly[（5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl）-alt-（3,3＇-di（2- dodecyltetradecyl）-2,2＇;5＇,2＂;5＂,2＇-quaterthiophen-5,5＇＂-diyl）] （PffBT4T-2DT）, with suitably complementary absorption spectra and energy levels were applied and examined. Among all different donor-acceptor pairs studied here, the combination of PTB7-Th：poly[NN-bis（1-hexylheptyl）-3,4,9,10-pery,enediimide-1,6/1,7-diyl-alt-2,5-thiophene] （PDI-Th） exhibited the best power conversion efficiency （PCE） of 5.13%, with open-circuit voltage （Vo：） = 0.79 lV, short-circuit current density （Jsc） = 12.35 mA.cm-2 and fill-factor （FF） = 0.52. The polymer of PDI-Th acceptor used here had a regio-irregular backbone, conveniently prepared from a mixture of 1,6- and 1,7-dibromo-PDI. It is also noteworthy that neither additive nor post- treatment is required for obtaining such a cell performance.展开更多
Synthetic polypeptides,also known as poly(α-amino acid)s(PαAAs),are biomimetic and biodegradable polymers holding great potential for a variety of biomedical applications.Possessing the same peptide bonds as natural...Synthetic polypeptides,also known as poly(α-amino acid)s(PαAAs),are biomimetic and biodegradable polymers holding great potential for a variety of biomedical applications.Possessing the same peptide bonds as natural proteins,polypeptides can also adopt typical well-defined secondary structures includingα-helix,which have been shown to significantly impact the physicochemical properties and biological outcomes of materials.In this feature article,we review the state-of-the-art progresses ofα-helical polypeptides for biomedical applications,with a special emphasis on the manipulation of helix-to-coil dynamic transition,conformation-associated anti-biofouling coatings,cellular uptake regulation,and reducing immunogenicity of polypeptide-protein conjugates.Finally,perspectives on outstanding challenges remained in this field and some important future directions are discussed.展开更多
The ring-opening polymerization of heterocyclic monomers and the reversed ring-closing depolymerization of corresponding polymers with neutral thermodynamics are broadly explored to establish a circular economy of nex...The ring-opening polymerization of heterocyclic monomers and the reversed ring-closing depolymerization of corresponding polymers with neutral thermodynamics are broadly explored to establish a circular economy of next-generation plastics.Polythioesters(PTEs),analogues of polyesters,are emerging materials for this purpose due to their high refractive index,high crystallinity,dynamic property and responsiveness.In this work,we synthesize and polymerize a series of D-penicillamine-derivedβ-thiolactones(NRPenTL)with varied side chain alkyl groups,and study the structure-property relationship of the resulting polymers.The obtained PTEs exhibit tunable glass transition temperature in a wide range of 130–50℃,and melting temperature of 90–105℃.In addition,copolymerizations of monomers with different side chains are effective in modulating material properties.The obtained homo and copolymers can be fully depolymerized to recycle monomers.This work provides a robust molecular platform and detailed structure-property relationship of PTEs with potential of achieving sustainable plastics.展开更多
G-quadruplexes （G4s） play important roles in biological systems, such as telomere maintenance, replication, and transcription. Based on the DNA sequence, loop geometry, and the local environments, G4s can be classif...G-quadruplexes （G4s） play important roles in biological systems, such as telomere maintenance, replication, and transcription. Based on the DNA sequence, loop geometry, and the local environments, G4s can be classified into different conformations. It is important to detect different types of G4s to monitor the diseases related with G4s. Most ligands bind to G4s based on end-stacking modes, while rare ligands bind to G4s through groove binding modes. We have found that a cyanine dye DMSB interacts with parallel G4 by end-stacking and groove simultaneous binding mode. In this article, we found that DMSB could simply discriminate parallel G4s from other DNA motifs by using UV-vis spectrum. These results give some clues to develop high specificity G4 probes.展开更多
Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also ...Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also on their structures. Here, we report assembly and disassembly of two cyanine dyes,a dimeric cyaine dye(TC-P4) and its corresponding monomer(TC). In PBS, these dyes could form aggregates. The parallel c-myc G-quadruplex as a template causes the transformation of TC-P4 from Haggregates to dimer and monomer; while duplex and single-stranded DNAs could not. The interaction between these DNAs motifs and TC could all induce the appearance of monomer band. Parallel c-myc Gquadruplex could enhance the fluorescence intensity of TC-P4 and TC. The self-assembly and disassembly of TC and TC-P4 could be regulated and used as probes for G-quadruplex recognition from duplex and single-stranded DNAs in solution.展开更多
Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal...Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal- and pH-responsive hydrogel based on an amino acid gelator AA-Azo-EG6. Specifically, the gelator bears an amino acid head, an azobenzene （Azo） linker, and a short oligoethylene glycol tail （EG6）. The resulting AA-Azo-EG6 hydrogel is injectable and exhibits interesting helical self-assembled structures, Meanwhile, the hydrogel is able to experience a gel-sol or gel-precipitate phase transition responding to external stimuli. Thus, this AA-Azo-EG6 gelator is a promising building block for intelligent materials and drug delivery.展开更多
To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic ef...To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.展开更多
Recent advancements in DNA and RNA bioengineering have paved the way for developing stimuli-responsive nanostructures with remarkable potential across various applications.These nanostructures,crafted through sophisti...Recent advancements in DNA and RNA bioengineering have paved the way for developing stimuli-responsive nanostructures with remarkable potential across various applications.These nanostructures,crafted through sophisticated bioengineering techniques,can dynamically and precisely respond to both physiological and physical stimuli,including nucleic acids(DNA/RNA),adenosine triphosphate,proteins,ions,small molecules,pH,light,and temperature.They offer high sensitivity and specificity,making them ideal for applications such as biomarker detection,gene therapy,and controlled targeted drug delivery.In this review,we summarize the bioengineering methods used to assemble versatile stimuli-responsive DNA/RNA nanostructures and discuss their emerging applications in structural biology and biomedicine,including biosensing,targeted drug delivery,and therapeutics.Finally,we highlight the challenges and opportunities in the rational design of these intelligent bioengineered nanostructures.展开更多
Oxidized copper(Cu)species have shown significant promise for electrocatalytic CO_(2)reduction reaction(CO_(2)RR),but they are hard to retain for longterm operation at negative potential.Herein,we developed a substrat...Oxidized copper(Cu)species have shown significant promise for electrocatalytic CO_(2)reduction reaction(CO_(2)RR),but they are hard to retain for longterm operation at negative potential.Herein,we developed a substrate-anchored thermal annealing strategy to synthesize a CuO/MgO catalyst for CO_(2)RR to CH_(4)with a Faradaic efficiency(FE)of 82.3%and a current density as high as 568.2 mA cm^(-2)at-1.0 V vs.reversible hydrogen electrode.This catalyst also demonstrates exceptional electrocatalytic durability and stability under industrially relevant conditions.In the membrane electrode assembly,the catalyst exhibited a CH_(4)FE of~70%at a current density of 500 mA cm^(-2),along with excellent stability,maintaining operation for 65 h at a cell voltage of~3.6 V.Detailed in-situ characterizations and theoretical calculations confirm that the strong electronic metal-support interactions between CuO clusters and MgO support not only stabilize the Cu^(2+)sites but also optimize the adsorption energies of the key intermediates to promote the CH_(4)pathway.Our insights guide the design of efficient and durable electrocatalyst for CO_(2)methanation.展开更多
Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric prope...Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric properties.However,synthesizing non-precious ordered intermetallics that exhibit high stability under operating conditions remains a formidable challenge,primarily owing to their strong oxyphilicity,highly negative reduction potentials,and low corrosion resistance.In this work,we report a facile yet versatile seed-mediated solid-phase approach for fabricating uniform Ni_(3)Ga_(1) intermetallic nanocubes(NCs)fully encapsulated within N-doped carbon layers(denoted as Ni_(3)Ga_(1)@NC-800).Extensive characterization confirms the formation of a unique core-shell architecture,with atomic-resolution structural analysis and X-ray absorption fine structure measurements unequivocally verifying the atomically ordered Ni_(3)Ga_(1) intermetallic phase.The Ni_(3)Ga_(1)@NC-800 catalyst demonstrates exceptional performance in the 1,4-hydrogenation of α,β-unsaturated carbonyl compounds,exhibiting both remarkable activity and exclusive selectivity while maintaining high stability over multiple reaction cycles without observable performance decay.Combined experimental and theoretical calculations reveal that the strong interatomic p-d orbital hybridization facilitates electron transfer from Ga to Ni atoms,resulting in electron localization on ordered Ni atoms.This electronic configuration positively influences H_(2)activation and optimizes substrate adsorption strength,thereby substantially improving catalytic efficiency.Furthermore,this synthetic strategy proves generalizable,successfully extending to the synthesis of other non-precious ordered Ni_(1)Sn_(1) and Ni_(2)In_(3) intermetallics confined within N-doped carbon matrices.展开更多
Molecular-based conducting magnet or magnetic conductor, is an overlap of organic conductor and molecular magnet. Due to the existence of ferromagnetism, antiferromagnetism and quantum magnetism in insulated charge-tr...Molecular-based conducting magnet or magnetic conductor, is an overlap of organic conductor and molecular magnet. Due to the existence of ferromagnetism, antiferromagnetism and quantum magnetism in insulated charge-transfer salt, it becomes a common sense that magnetism is not good for conductivity. After the discovery of first molecular-based metallic ferromagnet, molecular-based conducting magnet with n-unit from organic conductor and magnetism from coordination counterion became a hot area. The metallic ferromagnet, semiconductor room-temperature ferrimagnet, metallic weak ferromagnet and supercon- ducting antiferromagnet have been discovered. The new molecular-based conducting magnet with higher conductivity and higher magnetic ordering temperature is expected.展开更多
A new formulation of the Lindemann mechanism of unimolecular reactions in gaseous phase is presented,without the use of steady state hypothesis. It is hereby shown that the nature of applicability of steady state hypo...A new formulation of the Lindemann mechanism of unimolecular reactions in gaseous phase is presented,without the use of steady state hypothesis. It is hereby shown that the nature of applicability of steady state hypothesis in the regime of high reactant gas pressure is different from that in the regime of low gas pressure. In the former case it is an equilibrium approximation,while in the latter case it is a highly reactive intermediate approximation in no connection with a steady state. Furthermore for the latter case it is shown that in the classical formulation of Lindemann mechanism the use of steady state hypothesis is an ad hoc assumption. A highly reactive intermediate in the sense that its concentration is very small during the whole course of reaction is a necessary condition for the applicability of very reactive intermediate approximation. When the two distinctive nature of the applicability of steady state hypothesis is mixed-up,wrong or useless conclusion may be arrived at. The only possible case of realizing a true steady state in a complex reaction is pointed out.展开更多
G-quadruplexes attract more and more attention in recent years.Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug developmen...G-quadruplexes attract more and more attention in recent years.Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug development.As a motif existed in physiological condition,flanking sequences are an important part of G-quadruplexes but the study on the impact of flanking sequences on (G-quadruplex)-ligand binding is rarely reported.In this paper,the effects of flanking sequences on binding affinity between a series of unimolecular parallel-stranded G-quadruplex sequences derived from c-myc oncogene promoter (termed as c-myc G-quadruplexes) and their ligands are discussed in detail.The results showed that the flanking sequences on c-myc G-quadruplexes play key roles in (G-quadruplex)-ligand interaction.When a c-myc G-quadruplex is bound to its ligands,the flanking sequences might form a binding cavity above the terminal G-quartet,which could provide a suitable site for ligands to dock in.Moreover,the bases on flanking sequences could interact with ligand through π-π stacking,and finally form a sandwich-stacking mode (terminal G-quartet,ligand and bases on the flanking sequence).This mode could stabilize the (G-quadruplex)-ligand complex effectively and enhance the binding affinity dramatically.However,flanking sequences are also found to exhibit steric hindrance effect which could impede the (G-quadruplex)-ligand binding.展开更多
The ring-opening polymerization(ROP)of Ncarboxyanhydrides(NCAs)holds great potential for the efficient preparation of versatile and biocompatible poly(amino acid)s,such as polypeptides and polypeptoids.This perspectiv...The ring-opening polymerization(ROP)of Ncarboxyanhydrides(NCAs)holds great potential for the efficient preparation of versatile and biocompatible poly(amino acid)s,such as polypeptides and polypeptoids.This perspective highlights the pivotal role of proton transfer in NCA ROP,emphasizing the use of proton transfer catalysts(PTCs)such as carboxylic acids and water to enhance polymerization kinetics and achieve(unprecedented)polymers with high molecular weights.Further studies on the exploration and rational design of PTCs offers promising opportunities to further innovate NCA ROP chemistry and broaden its applications in material science.展开更多
Poly-L-hydroxyproline(PHyp)represents an important model for comprehending the polyproline II helix and holds immense potential for broad biomedical applications.The synthesis of PHyp,however,involves inefficient prot...Poly-L-hydroxyproline(PHyp)represents an important model for comprehending the polyproline II helix and holds immense potential for broad biomedical applications.The synthesis of PHyp,however,involves inefficient protection-deprotection steps and has been restricted to low molecular weight(MW)and linear topology.Here,we report the first ring-opening polymerization(ROP)of unprotected hydroxyproline N-carboxyanhydride(Hyp-NCA)for the facile synthesis of PHyp with tunable linear or branching topologies.While linear PHyp was readily prepared with control via water-assisted polymerization in minutes,tertiary amine-mediated ROP of Hyp-NCA affords branched PHyp(B-PHyp)for the first time with MW up to 438 kDa,∼40 times higher than the previous record.Experimental and computational studies collectively uncovered fresh insights into the general mechanism regarding the hydroxy/amine selectivity.Postpolymerization modification of B-PHyp affords injectable hydrogels with a critical gelization concentration as low as 1.0%.This study provides an approach that may inspire the development of novel synthetic collagen-like biomaterials.展开更多
Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered tra...Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered transition metal oxides into ultrathin nanosheets functionalized with phosphate species by the combination of ball-milling and liquid-exfoliation with phosphoric acid.The resulting HNb Mo O6nanosheets with supported Pd nanoparticles displayed excellent catalytic performance in the one-pot conversion of phenol into caprolactam(CPL),achieving a yield of up to 71.9%.This one-pot route avoids the energy-intensive intermediate separation process in conventional multi-step approaches to CPL.The superior catalytic performance of the catalysts is attributed to the tunable Bronsted acid/Lewis acid ratio and readily accessible active sites on the ultrathin nanosheets.This research demonstrates a new methodology for constructing ultrathin nanosheets and preparing bifunctional catalysts for tandem reactions,which opens the way for one-pot production of CPL.展开更多
The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review fo...The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review focuses on the transformation of CO_(2)and N_(2),highlighting their significance in green chemistry.We begin by discussing the fundamental principles of green chemistry and the advantages of utilizing CO_(2)and N_(2)to mitigate greenhouse gas emissions and reduce reliance on fossil resources.Subsequently,the review examines advanced transformation pathways for CO_(2)conversion,including electrocatalytic reduction,photocatalytic processes,and thermochemical transformations,evaluating their efficiency and scalability.The reduction of N_(2)and nitrogen oxides(NO_(x))to ammonia(NH_(3))is explored,presenting innovative alternatives to the traditional Haber-Bosch process that offer improved energy efficiency and lower environmental impact.Furthermore,the synthesis of nitrogenous compounds beyond NH_(3)is discussed,highlighting the versatility of green NH_(3)in the production of diverse chemicals.A key focus is placed on integrating CO_(2)and N_(2)transformations through C-N coupling reactions,enabling the direct formation of organic molecules with reduced environmental footprints.The review concludes by identifying current challenges and future directions,emphasizing the potential of catalytic technologies to foster a sustainable and resilient chemical industry.展开更多
This paper reports the chitosan-mediated synthesis of porous hematite nanoparticles with FeCl3 as the precursor via a hydrothermal approach at 160℃.A series of porous chitosan/iron oxide hybrid nanoparticles were obt...This paper reports the chitosan-mediated synthesis of porous hematite nanoparticles with FeCl3 as the precursor via a hydrothermal approach at 160℃.A series of porous chitosan/iron oxide hybrid nanoparticles were obtained via changing the ratio of chitosan to FeCl3,FeCl3 concentration and pH value of the reaction solution,and producing porous iron oxide nanoparticles after calcination.The as-prepared samples were characterized by means of X-ray diffraction,transmission electron microscopy,thermal gravimetric analysis,Fourier transform infrared,and N2 sorption.The particle sizes of these metal oxides were less than 100 nm,and the pore sizes were in the range of 2-16 nm.It was demonstrated that chitosan played a key role in the formation of the porous structures.The resultant α-Fe2O3 nanoparticles were used as the support to immobilize Au or Pd nanoparticles,producing Au/α-Fe2O3 or Pd/α-Fe2O3 nanoparticles.The as-prepared α-Fe2O3 nanocatalyst exhibited high selectivity towards cyclohexanone and cyclohexanol for catalyzing cyclohexane oxidation with O2 at 150℃.展开更多
基金the National Key R&D Program of China(No.2021YFC2101604)National Natural Science Foundation of China(Nos.U23A20123,22278339)+1 种基金Fujian Provincial Key Science and Technology Program of China(No.2022YZ037013)Xiamen University for the financial support.
文摘Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.
基金supported by the National Key Research and Development Program of China(2020YFA0710201)the China Postdoctoral Science Foundation Funded Project(2021M701211)+1 种基金Fundamental Research Funds for the Central Universities,“Island Atmosphere and Ecology”Category Ⅳ Peak Discipline(No.QN202505)the National Natural Science Foundation of China(22293015,22121002).
文摘Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.
基金financially supported by the National Natural Science Foundation of China(Nos.21674001 and 51473003)
文摘Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor polymers, poly[4,8-bis（5-（2-ethylhexyl）thiophen-2-yl）benzo[ 1,2-b;4,5-b＇]dithiophene-2,6-diyl-alt-（4-（2-ethylhexyl）-3-fluorothieno[3,4- b]thiophene）-2-carboxylate-2,6-diyl] （PTB7-Th） and poly[（5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl）-alt-（3,3＇-di（2- dodecyltetradecyl）-2,2＇;5＇,2＂;5＂,2＇-quaterthiophen-5,5＇＂-diyl）] （PffBT4T-2DT）, with suitably complementary absorption spectra and energy levels were applied and examined. Among all different donor-acceptor pairs studied here, the combination of PTB7-Th：poly[NN-bis（1-hexylheptyl）-3,4,9,10-pery,enediimide-1,6/1,7-diyl-alt-2,5-thiophene] （PDI-Th） exhibited the best power conversion efficiency （PCE） of 5.13%, with open-circuit voltage （Vo：） = 0.79 lV, short-circuit current density （Jsc） = 12.35 mA.cm-2 and fill-factor （FF） = 0.52. The polymer of PDI-Th acceptor used here had a regio-irregular backbone, conveniently prepared from a mixture of 1,6- and 1,7-dibromo-PDI. It is also noteworthy that neither additive nor post- treatment is required for obtaining such a cell performance.
基金financially supported by the National Key Research and Development Program of China (No. 2019YFA0904203)the National Natural Science Fund for Distinguished Young Scholars (No. 22125101)
文摘Synthetic polypeptides,also known as poly(α-amino acid)s(PαAAs),are biomimetic and biodegradable polymers holding great potential for a variety of biomedical applications.Possessing the same peptide bonds as natural proteins,polypeptides can also adopt typical well-defined secondary structures includingα-helix,which have been shown to significantly impact the physicochemical properties and biological outcomes of materials.In this feature article,we review the state-of-the-art progresses ofα-helical polypeptides for biomedical applications,with a special emphasis on the manipulation of helix-to-coil dynamic transition,conformation-associated anti-biofouling coatings,cellular uptake regulation,and reducing immunogenicity of polypeptide-protein conjugates.Finally,perspectives on outstanding challenges remained in this field and some important future directions are discussed.
基金supported by the National Science Fund for Distinguished Young Scholars(No.22125101).
文摘The ring-opening polymerization of heterocyclic monomers and the reversed ring-closing depolymerization of corresponding polymers with neutral thermodynamics are broadly explored to establish a circular economy of next-generation plastics.Polythioesters(PTEs),analogues of polyesters,are emerging materials for this purpose due to their high refractive index,high crystallinity,dynamic property and responsiveness.In this work,we synthesize and polymerize a series of D-penicillamine-derivedβ-thiolactones(NRPenTL)with varied side chain alkyl groups,and study the structure-property relationship of the resulting polymers.The obtained PTEs exhibit tunable glass transition temperature in a wide range of 130–50℃,and melting temperature of 90–105℃.In addition,copolymerizations of monomers with different side chains are effective in modulating material properties.The obtained homo and copolymers can be fully depolymerized to recycle monomers.This work provides a robust molecular platform and detailed structure-property relationship of PTEs with potential of achieving sustainable plastics.
基金supported by Major National Basic Research Projects (973,No.2013CB733701)National Natural Science Foundation of China (Nos.81072576,91027033,21302188,21205121,21305145 and 31200576)Chinese Academy of Sciences (No.KJCX2-EW-N06-01)
文摘G-quadruplexes （G4s） play important roles in biological systems, such as telomere maintenance, replication, and transcription. Based on the DNA sequence, loop geometry, and the local environments, G4s can be classified into different conformations. It is important to detect different types of G4s to monitor the diseases related with G4s. Most ligands bind to G4s based on end-stacking modes, while rare ligands bind to G4s through groove binding modes. We have found that a cyanine dye DMSB interacts with parallel G4 by end-stacking and groove simultaneous binding mode. In this article, we found that DMSB could simply discriminate parallel G4s from other DNA motifs by using UV-vis spectrum. These results give some clues to develop high specificity G4 probes.
基金financially supported by General Program of the National Natural Science Foundation of China(Nos. 21472197. 21675126 and 21778058)"Science and Technology Service Network Initiative" of the Chinese Academy of Sciences
文摘Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also on their structures. Here, we report assembly and disassembly of two cyanine dyes,a dimeric cyaine dye(TC-P4) and its corresponding monomer(TC). In PBS, these dyes could form aggregates. The parallel c-myc G-quadruplex as a template causes the transformation of TC-P4 from Haggregates to dimer and monomer; while duplex and single-stranded DNAs could not. The interaction between these DNAs motifs and TC could all induce the appearance of monomer band. Parallel c-myc Gquadruplex could enhance the fluorescence intensity of TC-P4 and TC. The self-assembly and disassembly of TC and TC-P4 could be regulated and used as probes for G-quadruplex recognition from duplex and single-stranded DNAs in solution.
基金supported by [18_TD$IF]State High-Tech Development Program of China (863 Program, No. 2015AA020941)the National Natural Science Foundation of China(Nos. NSFC21474004 and NSFC21434008)the Youth Thousand-Talents Program of China for support
文摘Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal- and pH-responsive hydrogel based on an amino acid gelator AA-Azo-EG6. Specifically, the gelator bears an amino acid head, an azobenzene （Azo） linker, and a short oligoethylene glycol tail （EG6）. The resulting AA-Azo-EG6 hydrogel is injectable and exhibits interesting helical self-assembled structures, Meanwhile, the hydrogel is able to experience a gel-sol or gel-precipitate phase transition responding to external stimuli. Thus, this AA-Azo-EG6 gelator is a promising building block for intelligent materials and drug delivery.
基金supported by National Natural Science Foundation of China (22033009, 22121002, 22238011)。
文摘To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.
文摘Recent advancements in DNA and RNA bioengineering have paved the way for developing stimuli-responsive nanostructures with remarkable potential across various applications.These nanostructures,crafted through sophisticated bioengineering techniques,can dynamically and precisely respond to both physiological and physical stimuli,including nucleic acids(DNA/RNA),adenosine triphosphate,proteins,ions,small molecules,pH,light,and temperature.They offer high sensitivity and specificity,making them ideal for applications such as biomarker detection,gene therapy,and controlled targeted drug delivery.In this review,we summarize the bioengineering methods used to assemble versatile stimuli-responsive DNA/RNA nanostructures and discuss their emerging applications in structural biology and biomedicine,including biosensing,targeted drug delivery,and therapeutics.Finally,we highlight the challenges and opportunities in the rational design of these intelligent bioengineered nanostructures.
基金the National Key Research and Development Program of China(2023YFA1507400)the National Natural Science Foundation of China(22102192,22279146,22033009,22293015,22121002)+2 种基金the CAS Project for Young Scientists in Basic Research(YSBR-050)the Photon Science Center for Carbon Neutralitythe S&T Program of Hebei(B2021208074)for the support。
文摘Oxidized copper(Cu)species have shown significant promise for electrocatalytic CO_(2)reduction reaction(CO_(2)RR),but they are hard to retain for longterm operation at negative potential.Herein,we developed a substrate-anchored thermal annealing strategy to synthesize a CuO/MgO catalyst for CO_(2)RR to CH_(4)with a Faradaic efficiency(FE)of 82.3%and a current density as high as 568.2 mA cm^(-2)at-1.0 V vs.reversible hydrogen electrode.This catalyst also demonstrates exceptional electrocatalytic durability and stability under industrially relevant conditions.In the membrane electrode assembly,the catalyst exhibited a CH_(4)FE of~70%at a current density of 500 mA cm^(-2),along with excellent stability,maintaining operation for 65 h at a cell voltage of~3.6 V.Detailed in-situ characterizations and theoretical calculations confirm that the strong electronic metal-support interactions between CuO clusters and MgO support not only stabilize the Cu^(2+)sites but also optimize the adsorption energies of the key intermediates to promote the CH_(4)pathway.Our insights guide the design of efficient and durable electrocatalyst for CO_(2)methanation.
基金financially supported by the program of the National Natural Science Foundation of Shandong Province(No.ZR2023ZD23)the Shandong Province Key Research and Development Plan(No.2023CXGC010607).
文摘Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric properties.However,synthesizing non-precious ordered intermetallics that exhibit high stability under operating conditions remains a formidable challenge,primarily owing to their strong oxyphilicity,highly negative reduction potentials,and low corrosion resistance.In this work,we report a facile yet versatile seed-mediated solid-phase approach for fabricating uniform Ni_(3)Ga_(1) intermetallic nanocubes(NCs)fully encapsulated within N-doped carbon layers(denoted as Ni_(3)Ga_(1)@NC-800).Extensive characterization confirms the formation of a unique core-shell architecture,with atomic-resolution structural analysis and X-ray absorption fine structure measurements unequivocally verifying the atomically ordered Ni_(3)Ga_(1) intermetallic phase.The Ni_(3)Ga_(1)@NC-800 catalyst demonstrates exceptional performance in the 1,4-hydrogenation of α,β-unsaturated carbonyl compounds,exhibiting both remarkable activity and exclusive selectivity while maintaining high stability over multiple reaction cycles without observable performance decay.Combined experimental and theoretical calculations reveal that the strong interatomic p-d orbital hybridization facilitates electron transfer from Ga to Ni atoms,resulting in electron localization on ordered Ni atoms.This electronic configuration positively influences H_(2)activation and optimizes substrate adsorption strength,thereby substantially improving catalytic efficiency.Furthermore,this synthetic strategy proves generalizable,successfully extending to the synthesis of other non-precious ordered Ni_(1)Sn_(1) and Ni_(2)In_(3) intermetallics confined within N-doped carbon matrices.
基金financially supported by the National Natural Science Foundation of China (21173230)MOST (2011CE93202)
文摘Molecular-based conducting magnet or magnetic conductor, is an overlap of organic conductor and molecular magnet. Due to the existence of ferromagnetism, antiferromagnetism and quantum magnetism in insulated charge-transfer salt, it becomes a common sense that magnetism is not good for conductivity. After the discovery of first molecular-based metallic ferromagnet, molecular-based conducting magnet with n-unit from organic conductor and magnetism from coordination counterion became a hot area. The metallic ferromagnet, semiconductor room-temperature ferrimagnet, metallic weak ferromagnet and supercon- ducting antiferromagnet have been discovered. The new molecular-based conducting magnet with higher conductivity and higher magnetic ordering temperature is expected.
文摘A new formulation of the Lindemann mechanism of unimolecular reactions in gaseous phase is presented,without the use of steady state hypothesis. It is hereby shown that the nature of applicability of steady state hypothesis in the regime of high reactant gas pressure is different from that in the regime of low gas pressure. In the former case it is an equilibrium approximation,while in the latter case it is a highly reactive intermediate approximation in no connection with a steady state. Furthermore for the latter case it is shown that in the classical formulation of Lindemann mechanism the use of steady state hypothesis is an ad hoc assumption. A highly reactive intermediate in the sense that its concentration is very small during the whole course of reaction is a necessary condition for the applicability of very reactive intermediate approximation. When the two distinctive nature of the applicability of steady state hypothesis is mixed-up,wrong or useless conclusion may be arrived at. The only possible case of realizing a true steady state in a complex reaction is pointed out.
文摘G-quadruplexes attract more and more attention in recent years.Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug development.As a motif existed in physiological condition,flanking sequences are an important part of G-quadruplexes but the study on the impact of flanking sequences on (G-quadruplex)-ligand binding is rarely reported.In this paper,the effects of flanking sequences on binding affinity between a series of unimolecular parallel-stranded G-quadruplex sequences derived from c-myc oncogene promoter (termed as c-myc G-quadruplexes) and their ligands are discussed in detail.The results showed that the flanking sequences on c-myc G-quadruplexes play key roles in (G-quadruplex)-ligand interaction.When a c-myc G-quadruplex is bound to its ligands,the flanking sequences might form a binding cavity above the terminal G-quartet,which could provide a suitable site for ligands to dock in.Moreover,the bases on flanking sequences could interact with ligand through π-π stacking,and finally form a sandwich-stacking mode (terminal G-quartet,ligand and bases on the flanking sequence).This mode could stabilize the (G-quadruplex)-ligand complex effectively and enhance the binding affinity dramatically.However,flanking sequences are also found to exhibit steric hindrance effect which could impede the (G-quadruplex)-ligand binding.
基金supported by National Natural Science Foundation of China(22125101 and 22331002)supported by the National High Level Chemical Talent Center Fellowship.
文摘The ring-opening polymerization(ROP)of Ncarboxyanhydrides(NCAs)holds great potential for the efficient preparation of versatile and biocompatible poly(amino acid)s,such as polypeptides and polypeptoids.This perspective highlights the pivotal role of proton transfer in NCA ROP,emphasizing the use of proton transfer catalysts(PTCs)such as carboxylic acids and water to enhance polymerization kinetics and achieve(unprecedented)polymers with high molecular weights.Further studies on the exploration and rational design of PTCs offers promising opportunities to further innovate NCA ROP chemistry and broaden its applications in material science.
基金supported by the National Natural Science Foundation of China(grant nos.22331002 and 22125101)the Beijing Natural Science Foundation Key Project(grant no.Z220023)+1 种基金the Peking University Clinical Medicine plus X(grant no.ZX002)the Open Funding Project of the State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Preparation and Delivery(grant no.2023KF-01).
文摘Poly-L-hydroxyproline(PHyp)represents an important model for comprehending the polyproline II helix and holds immense potential for broad biomedical applications.The synthesis of PHyp,however,involves inefficient protection-deprotection steps and has been restricted to low molecular weight(MW)and linear topology.Here,we report the first ring-opening polymerization(ROP)of unprotected hydroxyproline N-carboxyanhydride(Hyp-NCA)for the facile synthesis of PHyp with tunable linear or branching topologies.While linear PHyp was readily prepared with control via water-assisted polymerization in minutes,tertiary amine-mediated ROP of Hyp-NCA affords branched PHyp(B-PHyp)for the first time with MW up to 438 kDa,∼40 times higher than the previous record.Experimental and computational studies collectively uncovered fresh insights into the general mechanism regarding the hydroxy/amine selectivity.Postpolymerization modification of B-PHyp affords injectable hydrogels with a critical gelization concentration as low as 1.0%.This study provides an approach that may inspire the development of novel synthetic collagen-like biomaterials.
基金supported by the National Key Research and Development Program of China(2022YFA1504901,2023YFA1508103)the National Natural Science Foundation of China(22293012,22179132,22293015,22121002)。
文摘Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered transition metal oxides into ultrathin nanosheets functionalized with phosphate species by the combination of ball-milling and liquid-exfoliation with phosphoric acid.The resulting HNb Mo O6nanosheets with supported Pd nanoparticles displayed excellent catalytic performance in the one-pot conversion of phenol into caprolactam(CPL),achieving a yield of up to 71.9%.This one-pot route avoids the energy-intensive intermediate separation process in conventional multi-step approaches to CPL.The superior catalytic performance of the catalysts is attributed to the tunable Bronsted acid/Lewis acid ratio and readily accessible active sites on the ultrathin nanosheets.This research demonstrates a new methodology for constructing ultrathin nanosheets and preparing bifunctional catalysts for tandem reactions,which opens the way for one-pot production of CPL.
基金supported by the National Key Research and Development Program of China(2024YFE0206400)the National Natural Science Foundation of China(22293015 and 22121002)+2 种基金the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA0390402)Chinese Academy Sciences Project for Young Scientists in Basic Research(YSBR-05O)Photon Science Center for Carbon Neutrality.
文摘The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review focuses on the transformation of CO_(2)and N_(2),highlighting their significance in green chemistry.We begin by discussing the fundamental principles of green chemistry and the advantages of utilizing CO_(2)and N_(2)to mitigate greenhouse gas emissions and reduce reliance on fossil resources.Subsequently,the review examines advanced transformation pathways for CO_(2)conversion,including electrocatalytic reduction,photocatalytic processes,and thermochemical transformations,evaluating their efficiency and scalability.The reduction of N_(2)and nitrogen oxides(NO_(x))to ammonia(NH_(3))is explored,presenting innovative alternatives to the traditional Haber-Bosch process that offer improved energy efficiency and lower environmental impact.Furthermore,the synthesis of nitrogenous compounds beyond NH_(3)is discussed,highlighting the versatility of green NH_(3)in the production of diverse chemicals.A key focus is placed on integrating CO_(2)and N_(2)transformations through C-N coupling reactions,enabling the direct formation of organic molecules with reduced environmental footprints.The review concludes by identifying current challenges and future directions,emphasizing the potential of catalytic technologies to foster a sustainable and resilient chemical industry.
基金supported by the Ministry of Science and Technology of China (2009CB930802)the Chinese Academy of Sciences (KJCX2.YW.H16)
文摘This paper reports the chitosan-mediated synthesis of porous hematite nanoparticles with FeCl3 as the precursor via a hydrothermal approach at 160℃.A series of porous chitosan/iron oxide hybrid nanoparticles were obtained via changing the ratio of chitosan to FeCl3,FeCl3 concentration and pH value of the reaction solution,and producing porous iron oxide nanoparticles after calcination.The as-prepared samples were characterized by means of X-ray diffraction,transmission electron microscopy,thermal gravimetric analysis,Fourier transform infrared,and N2 sorption.The particle sizes of these metal oxides were less than 100 nm,and the pore sizes were in the range of 2-16 nm.It was demonstrated that chitosan played a key role in the formation of the porous structures.The resultant α-Fe2O3 nanoparticles were used as the support to immobilize Au or Pd nanoparticles,producing Au/α-Fe2O3 or Pd/α-Fe2O3 nanoparticles.The as-prepared α-Fe2O3 nanocatalyst exhibited high selectivity towards cyclohexanone and cyclohexanol for catalyzing cyclohexane oxidation with O2 at 150℃.
