Regulation of Lithium-Ion Flux by Nanotopology Lithiophilic Boron-Oxygen Dipole in Solid Polymer Electrolytes for Lithium-Metal Batteries

Inhomogeneous lithium-ion(Li^(+))deposition is one of the most crucial problems,which severely deteriorates the performance of solid-state lithium metal batteries(LMBs).Herein,we discovered that covalent organic framework(COF-1)with periodically arranged boron-oxygen dipole lithiophilic sites could directionally guide Li^(+)even deposition in asymmetric solid polymer electrolytes.This in situ prepared 3D cross-linked network Poly(ACMO-MBA)hybrid electrolyte simultaneously delivers outstanding ionic conductivity(1.02×10^(-3)S cm^(-1)at 30°C)and excellent mechanical property(3.5 MPa).The defined nanosized channel in COF-1 selectively conducts Li^(+)increasing Li^(+)transference number to 0.67.Besides,The COF-1 layer and Poly(ACMO-MBA)also participate in forming a boron-rich and nitrogen-rich solid electrolyte interface to further improve the interfacial stability.The Li‖Li symmetric cell exhibits remarkable cyclic stability over 1000 h.The Li‖NCM523 full cell also delivers an outstanding lifespan over 400 cycles.Moreover,the Li‖LiFePO_(4)full cell stably cycles with a capacity retention of 85%after 500 cycles.the Li‖LiFePO_(4)pouch full exhibits excellent safety performance under pierced and cut conditions.This work thereby further broadens and complements the application of COF materials in polymer electrolyte for dendrite-free and high-energy-density solid-state LMBs.

Simultaneous regulation on coordination environment and interfacial chemistry via taurine for stabilized Zn metal anode

Aqueous Zn-ion batteries(AZIBs)are the potential options for the next-generation energy storage scenarios due to the cost effectiveness and intrinsic safety.Nevertheless,the industrial application of AZIBs is still impeded by a series of parasitic reactions and dendrites at zinc anodes.In this study,taurine(TAU)is used in electrolyte to simultaneously optimize the coordination condition of the ZnSO4electrolyte and interfacial chemistry at the anode.TAU can preferentially adsorb with the zinc metal and induce an in situ stable and protective interface on the anode,which would avoid the connection between H_(2)O and the zinc metal and promote the even deposition of Zn^(2+).The resulting Zn//Zn batteries achieve more than 3000 hours long cyclic lifespan under 1 mA cm^(-2)and an impressive cumulative capacity at 5 mA cm^(-2).Moreover,Zn//Cu batteries can realize a reversible plating/stripping process over 2,400cycles,with a desirable coulombic efficiency of 99.75%(1 mA cm^(-2)).Additionally,the additive endows Zn//NH_(4)V_(4)O_(10)batteries with more stable cyclic performance and ultrafast rate capability.These capabilities can promote the industrial application of AZIBs.

Conversion mechanism of NiCo_(2)Se_(4)nanotube sphere anodes for potassium-ion batteries

Given the abundance of potassium resources,potassium-ion batteries are considered a low-cost alternative to lithium-ion types.However,their electrochemical performance remains rather unsatisfactory because potassium ions have sluggish kinetics and large ionic radius.In this study,NiCo_(2)Se_(4)nanotube spheres are synthesized as efficient potassium storage hosts via a facile two-step hydrothermal process.The rationally designed electrode has various ameliorating morphological and functional features,including the following:(i)A hollow structure allows for relief of the volume expansion while offering an excellent electrochemical reac-tivity to accelerate the conversion kinetics;(ii)a high electrical conductivity for enhanced electron transfer;and(iii)myriad vacancies to supply active sites for electrochemical reactions.As such,the electrode delivers an initial reversible capacity of 458.1 mAh g^(−1)and retains 346.6 mAh g^(−1)after 300 cycles at 0.03 A g^(−1).The electrode sustains a high capacity of 101.4 mAh g^(−1)even at a high current density of 5 A g^(−1)and outperforms the majority of state-of-the-art anodes in terms of both cyclic capacity and rate capability,especially at above 1.0 A g^(−1).This study not only proves bimetallic selenides are promising candidates for potassium storage devices but also offers new insight into the rational design of electrode materials for high-rate potassium-ion batteries.

Simultaneous integration of Fe clusters and NiFe dual single atoms in nitrogen-doped carbon for oxygen reduction reaction

Atomically-dispersed iron-based electrocatalysts are promising substitutes for noble metal electrocatalysts because of excellent performance in oxygen reduction reaction(ORR).Rationally modulating the local coordination environment of the Fe site and optimizing the binding energy of oxygen reduction intermediates are effective strategies to optimize ORR activity.Herein,we report a new method in which Ni is introduced to construct NiFe dual single atoms and iron nanoclusters loaded on the nitrogen-doped carbon with a highly porous structure.This design plays a synergistic role of dual single atoms and clusters,optimizes the 3d orbital and Fermi level of Fe,breaks the symmetrical structure of Fe-N_(4),and effectively improves the adsorption/desorption behavior of the oxygen-containing intermediates.Electrochemical tests show FeNCs/NiFeSAs-NC has an excellent intrinsic activity.Theoretical calculations show the oxygen-containing species on the Ni active site will move to the middle of NiFe(bridge site connection)after optimization and that the key step is OH desorption,with a reaction energy of 0.27 eV.The electron exchange between NiFe-N6 and Fe-cluster is very strong,further indicating the introduction of Ni species and Fe clusters has a regulatory effect on the electronic structure of Fe-N_(4).

Synergistic Effect of Nitrogen/Phosphorus Co-Doping and Molybdenum Carbide Induced Electron Redistribution of Carbon Layer to Boost Hydrogen Evolution Reaction

The development of highly efficient non-precious-metal-based electrocatalysts for the hydrogen evolution reaction is imperative for promoting the large-scale application of electrochemical water splitting.Herein,nitrogen/phosphorus co-doped carbon nanorods encapsulated Mo_(2)C nanoparticles(Mo_(2)C@PNc)have been prepared by pre-phosphating treatment in combination of the coordination with polydopamine and the subsequent pyrolysis.The phosphating temperature has a significant effect on the content of phosphorus within the resultant Mo_(2)C@PNC,and the optimal catalyst delivers superior HER activity with the low overpotential of 104 mV at a current density of 10 mAcm^(-2) and good stability for 8 h,which has been theoretically demonstrated to originate from the synergistic effect between P doping and Mo_(2)C induced electron redistribution of nitrogen-doped carbon layer.

Fine-tuning redox ability of arylene-bridged bis(benzimidazolium)for electrochromism and visible-light photocatalysis

In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2[OTf^(–)]with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states.The inclusion of an anthracene unit as theπ-linker contributes to its exceptional redox and optoelectronic characteristics.Consequently,1^(2+)·2[OTf^(–)]was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time,and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions.

Insights into Reduction of CO_(2) to CO Catalyzed by Pyramidal-4Ni Clusters Supported on Doped CeO_(2)

Converting CO_(2) into valuable chemicals has become a widely used research method for CO_(2) conversion.In this work,the catalytic performance of pyramidal-4Ni catalysts supported on rare earth metal-doped CeO_(2)toward CO_(2) reductionreaction(CO_(2)RR)was investigated by using density-functional theorycalculations.For rare earth metal-doped CeO_(2),2Ce is substituted by 2 trivalent cations and at the same time one oxygen vacancy is created to make charge compensation.We investigated the oxygen vacancy nearest(Vo,N)and next-nearest(Vo,NN)to 4Ni,and found releasing CO and CO_(2) dissociation are the rate-determining steps,respectively,via the path of Vo,N and Vo,NN.Among the studied dopants(Ga,Sb,Lu,Gd,Pr,La,Bi),Gd is identified as the best dopant for catalyzing the reduction of CO_(2) at 823 K,with the turn-over frequency(TOF)of 104 times as large as that over 4Ni supported on pure CeO_(2).This exploration provides theoretical support and guidance for the research and application of rare earth metaldoped CeO_(2)-loaded Ni catalysts in the field of CO_(2) reduction.

Periodic Defect Boundary-Mediated Activity of Electrocatalytic Oxygen Reduction Reactions of Fe-N-C Catalysts

The introduction of defects can adjust the activity of graphene-based single-atom catalysts for oxygen reduction reactions(ORR).Herein,we for the first time investigate the ORR catalytic activity of FeN_(4)sites embedded on graphene with four types of line-defective boundary via density functional theory calculations.Our results show that periodic line defects consisting of pentagon-pentagon-octagon(C_(585))or quad-octagon chains(C_(484))can significantly enhance ORR activity,owing to the optimized electronic structures of FeN_(4)sites.The spin magnetic moment and the valence state of the Fe atom are both well correlated with the ORR overpotential.Experimental investigations further corroborate that FeN_(4)with a high degree of defects exhibits better ORR activity and stability compared to FeN_(4)sites of pristine graphene and commercial Pt/C.This work unravels the influence of the periodic defect boundary on the ORR performance of Fe-N-C catalysts and paves the way towards the rational design of highly effective single-atom electrocatalysts.

Progress in processing of porous titanium:a review

As a novel structural and functional material,porous titanium and its alloys have been widely used in the aerospace,marine engineering and biomedical fields due to their high corrosion resistance,low density,good biocompatibility and excellent mechanical properties.Therefore,in this paper,a comprehensive review of powder metallurgy(PM)(including additive manufacturing(AM)processes)for fabricating porous titanium is firstly covered in terms of their working principles,capabilities,shortcomings and strengths.Simultaneously,the influencing factors of various methods on final pore structure of porous Ti are involved.Secondly,a summary of the chemical methods(CM)to obtain the porous Ti is also provided,such as dealloying method and reduction method.Finally,the tendency and direction of preparation technology as well as application of porous titanium were prospected.

Photoredox catalytic alkylarylation of alkynes with arylsulfonylacetate as bifunctional reagent

Difunctionalization of alkynes represents a powerful and straightforward approach to the synthesis of complex molecules.However,the radical difunctionalization of alkynes mediated by bifunctional reagents remains challenging and underexplored,despite significant progress having been made in alkene difunctionalization.Here,we report a novel arylsulfonylacetate skeleton in which aryl rings are attached to acetates through SO_(2),serving as a powerful bifunctional reagent for the alkylarylation of alkynes via vinyl-radical intermediate under photoredox conditions.This modular bifunctional reagent enables the simultaneous incorporation of a wide range of functional groups,including(hetero)aryl ring and alkyl carboxylate into alkynes,resulting in synthetically valuable all-carbon tetrasubstituted alkene derivatives.This transformation is distinguished by its redox-neutral nature,readily accessible starting materials,compatibility with diverse functional groups and its capacity to facilitate convergent synthesis.The utility of this approach was further demonstrated by the late-stage functionalization of complex molecules and the preparation of fluorescent molecules and anti-cancer drugs.

How the microenvironment dominated by the distance effect to regulate the FeN_(4)site ORR activity and selectivity?

The distance effect of the doped heteroatoms away from the catalytic centers has rarely been reported.In this work,we conducted density functional theory calculations to thoroughly investigate the influence of heteroatom(N,P,B,and S atoms)doping distance on the oxygen reduction reaction(ORR)activity of graphene-based FeN_(4)sites.We uncovered a Sabatier-like relationship between heteroatom doping distance and ORR activity of FeN_(4)sites.The nearest doping does not significantly improve and even block the ORR activity of FeN_(4)sites.Optimal ORR activity is achieved when the heteroatoms are 4-5Å(N,P,and S atoms)or 6-7Å(B atoms)away from the Fe atoms.Analysis of electronic structure indicates that distance effect can modulate the local chemical environment of Fe atoms,thereby account for the changes in ORR activity along with the doping distance and doping atoms.This study provides insights into the influence of heteroatom doping on the chemical environment of reaction active centers,and provides the theoretical guidance for controlling the doping distance of heteroatoms to achieve optimal catalytic activity and selectivity.

Dynamic Sulfur-Rich Polymers from Elemental Sulfur and Epoxides

Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high reversibility.Utilizating sulfur, an inexpensive industrial waste product, to synthesize dynamic polysulfide polymers through reverse vulcanization has been a notable approach. However, this method required high temperatures and resulted in the release of unpleasant oders. In this study, we presented a robust method for the preparation of sulfur-rich polymers with dynamic polysulfide bonds from elemental sulfur and inexpensive epoxide monomers via a one-pot strategy at the mild room temperature. Different types of polysulfide molecules and polymers were synthesized by reacting various epoxide compounds with sulfur, along with the investigation of their structures and dynamic behaviors. It was noteworthy that the obatined polymers prepared from m-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline and elemental sulfur exhibit multiple dynamic behaviors, including polysulfide metathesis and polysulfide-thiol exchange, enabling their rapid stress relaxation, self-healing, reprocessing and degradable properties of the cross-linked polymer. More importantly, the hydroxyl groups at the side chains from epoxide ring opening exhibited potential transesterification. This work provided a facile strategy for designing dynamic sulfur-rich polymers via a mild synthesis route.

Nickel-catalyzed carbonylative four-component 1,4-dicarbofunctionalization of 1,3-enynes

An efficient Ni-catalyzed four-component 1,4-carbocarbonylation of 1,3-enynes with activated alkyl halides and arylboronic acids under atmospheric pressure of CO is presented.By tuning the electronic and steric effects of alkyl radicals,both electronrich and electron-deficient 1,3-enynes were compatible with this cascade.This protocol features mild conditions,broad substrate scope,excellent functional group compatibility and facile gram-scale synthesis,providing a practical approach to the quaternary carbon center-containing allenyl ketones.Mechanistic study revealed that the acyl-NiIIspecies plays an important role in both the coupling and the alkyl radical generation processes.

Lone pair-π interaction induced regioselective sulfonation of ethers under light irradiation

Non-covalent interactions are of significance in supramolecular chemistry and biochemistry,while synthetic procedures driven by these weak interactions remain challenging and rare.Inspired by the lone pair-π interaction presence in the Z-DNA structure,a light-induced regioselective sulfonation of ethers taking advantage of the lone pair-π interaction between the oxygen of ethers and sulfonyl chlorides has been disclosed.Moreover,this strategy is also applicable to the sulfonation of aniline derivatives.Features of the methods include readily accessible starting materials,high atom-economy,green and photocatalyst-free conditions and broad functional group tolerance.Mechanism studies suggest that the lone pair-πinteraction plays an important role to initiate the transformation.

Recent progress in advanced catalysts for electrocatalytic hydrogenation of organics in aqueous conditions

Electrocatalytic hydrogenation(ECH)of organics using water as hydrogen donors has been regarded as a green organic reduction technique to replace traditional chemical reactions that use sacrificial chemicals.The development of ECH process provides potential applications in the production of value-added chemicals owing to its low energy consumption,low pollution,high safety,and superior sustainability.However,its application is limited by the low conversion rate and poor selectivity toward desired products.The efficiency of ECH can be improved by rational design of electrocatalysts.This review covers several representative electrocatalytic systems(aldehydes,ketones,phenolic organics,alkynes,and organonitrogen compounds)and summarizes different ECH mechanisms,followed by thorough discussion on the modification strategies of electrocatalysts that are currently adopted to enhance the catalytic performance.Finally,in view of the current challenges for ECH,we discuss possible future directions in the field,aiming to provide guidance to the catalyst design toward highly efficient ECH reactions over different organic feedstocks.

Recent Advances in Wide-Range Temperature Metal-CO_(2)Batteries:A Mini Review

The metal-carbon dioxide batteries,emerging as high-energy-density energy storage devices,enable direct CO_(2)utilization,offering promising prospects for CO_(2)capture and utilization,energy conversion,and storage.However,the electrochemical performance of M-CO_(2)batteries faces significant challenges,particularly at extreme temperatures.Issues such as high overpotential,poor charge reversibility,and cycling capacity decay arise from complex reaction interfaces,sluggish oxidation kinetics,inefficient catalysts,dendrite growth,and unstable electrolytes.Despite significant advancements at room temperature,limited research has focused on the performance of M-CO_(2)batteries across a wide-temperature range.This review examines the effects of low and high temperatures on M-CO_(2)battery components and their reaction mechanism,as well as the advancements made in extending operational ranges from room temperature to extremely low and high temperatures.It discusses strategies to enhance electrochemical performance at extreme temperatures and outlines opportunities,challenges,and future directions for the development of M-CO_(2)batteries.

氨基酸基防污可注射自融合水凝胶的制备及其在术后防粘连中的应用

设计和制备具有优异防污能力的可注射防粘连材料对预防手术后组织和器官的粘连具有重要的意义.在此,我们将含有羟基的氨基酸衍生物引入水凝胶的制备中,通过N-丙烯酰丝氨酸(ASer)的自由基聚合制备了一种新型的氢键交联水凝胶(PASer).结果发现一个甲基取代基的存在会对分子间氢键相互作用产生明显的影响:与聚(N-丙烯酰苏氨酸)(PAThr)水凝胶相比,PASer水凝胶具有较低的成胶浓度和增强的力学性能.值得一提的是,亲水性羟基使PASer水凝胶能够有效抵抗蛋白质吸附和细胞粘附.PASer水凝胶具有优异的力学性能、可注射性、自融合性、良好的生物相容性和适宜的体内停留时间,符合临床对术后抗粘连材料的要求.体内研究实验结果表明,PASer水凝胶在建立的小鼠腹壁缺损模型中可以有效预防术后腹膜粘连发生.

用于室温全固态锂金属电池的精准丁二腈官能团化聚氧化乙烯固态电解质

聚环氧乙烷(PEO)聚合物电解质有望应用于全固态锂金属电池.然而,目前还没有提出有效的方法制备全固态PEO电解质,以克服其在室温下无法使用的局限性.在本研究中,我们基于聚合物C-H键功能化策略,通过在聚合物链上直接共价连接具有锂配位活性的丁二腈官能团,设计出了一种高离子导电性PEO电解质.该官能团有效增强了PEO链的无序性和流动性,同时也作为链间快速离子传导的活性位点,从而实现了离子周围自由体积和迁移行为的双重优化.得益于官能团对离子输运的精准调节,新型电解质表现出更强的离子传导性(离子电导率提升100倍)、更高的转移数(tLi+=0.51)和更宽的电化学窗口(>0.47 V).特别是功能化的PEO300k电解质具有超高室温离子电导率(25℃时为1.01×10^(-4)S cm^(-1))并且能够在室温下稳定工作,该研究为开发具有实际应用价值的聚合物电解质提供了新的途径.

Photoinduced copper-catalyzed alkoxyl radical-triggered ring-expansion/aminocarbonylation cascade

A photoinduced copper-catalyzed alkoxyl triggered C-C bond cleavage/aminocarbonylation cascade is presented.Through adjusting the structure of alkoxyl radical precursors,functionalized lactones and ketoamides were synthesized with good yields and excellent functional group tolerance under redox-neutral conditions.Notably,this protocol enables the integration of lactone fragments with many amine drugs and drug fragments.

Tough Polymeric Hydrogels Based on Amino Acid Derivative Mediated Dynamic Metal Coordination Bonds

Abstract The development of physically crosslinked hydrogels with excellent mechanical and sensing properties is of importance for expanding the practical applications of intelligent soft hydrogel materials.Herein,after copolymerization of hydroxyl-containing amino acid derivative N-acryloyl serine(ASer)with acrylamide(AM),we introduce Zr4+through an immersion strategy to construct metal ion-toughened non-covalent crosslinked hydrogels(with tensile strength of up to 5.73 MPa).It is found that the synergistic coordination of hydroxyl and carboxyl groups with Zr^(4+)substantially increases the crosslinking density of the hydrogels,thereby imparting markedly superior mechanical properties compared to hydroxyl-free Zr^(4+)-crosslinked hydrogels,such as N-acryloyl alanine(AAla)copolymerized with AM hydrogels(with tensile strength of 2.98 MPa)Through the adjustment of the composition of the copolymer and the density of coordination bonds,the mechanical properties of the hydrogels can be modulated over a wide range.Additionally,due to the introduction of metal ions and the dynamic nature of coordination bonds,the hydrogels also exhibit excellent sensing performance and good self-recovery properties,paving the way for the development of flexible electronic substrates with outstanding comprehensive performances.