Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and...Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and controllable structures.COFs are widely used in the fields of adsorption and separation,catalysis,photovoltaics,and drug-delivery.The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods.In which,the types of linkage are closely related to the stability and performance of COFs.In this review,nitrogencontaining linkage-bonds(NCLBs)in COFs are divided into N-containing double bonds,N-containing conjugated rings and N-containing unconjugated rings.The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized.Moreover,the structural design,theoretical prediction and machinable application of COFs are prospected.展开更多
Lithium–sulfur(Li-S)batteries are regarded as one of the most promising energy storage devices because of their low cost,high energy density,and environmental friendliness.However,Li-S batteries suffer from sluggish ...Lithium–sulfur(Li-S)batteries are regarded as one of the most promising energy storage devices because of their low cost,high energy density,and environmental friendliness.However,Li-S batteries suffer from sluggish reaction kinetics and serious“shuttle effect”of lithium polysulfides(LiPSs),which causes rapid decay of battery capacity and prevent their practical application.To address these problems,introducing single-atom catalysts(SACs)is an effective method to improve the electrochemical performance of Li-S batteries,due to their high catalytic efficiency and definite active sites for LiPSs.In this paper,we summarized the latest developments in enhancing the electrochemical performance of cathode for Li-S batteries through introducing different SACs.Furthermore,we briefly introduced the catalytic mechanism of SACs and discussed the strategies of synthesizing SACs,including the spatial confinement strategy and the coordination design strategy.Finally,the challenges and prospects in this field are proposed.We believe that this review would help to design and fabricate high-performance Li-S batteries via introducing SACs and boost their practical application.展开更多
Subject Code:B02With the support by the National Natural Science Foundation of China and the National Basic Research Program of China,the research team led by Prof.Xia Haiping(夏海平)of Xiamen University described the...Subject Code:B02With the support by the National Natural Science Foundation of China and the National Basic Research Program of China,the research team led by Prof.Xia Haiping(夏海平)of Xiamen University described the first example of CCCCC pentadentate chelate with all binding atoms being carbon atoms.This result represents a new record of planar carbon coordination number for a transition metal,which was展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFD1700800 and 2023YFC3905903)the Science and Technology Project of Education Department of Jiangxi Province(No.GJJ2201103)+2 种基金the Fund of Nanchang Hangkong University(Nos.EA202201110 and EA202201065)National Undergraduate Innovation and Entrepreneurship Training Program(No.202310406023)the National Natural Science Foundation of China(No.52470149)。
文摘Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and controllable structures.COFs are widely used in the fields of adsorption and separation,catalysis,photovoltaics,and drug-delivery.The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods.In which,the types of linkage are closely related to the stability and performance of COFs.In this review,nitrogencontaining linkage-bonds(NCLBs)in COFs are divided into N-containing double bonds,N-containing conjugated rings and N-containing unconjugated rings.The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized.Moreover,the structural design,theoretical prediction and machinable application of COFs are prospected.
基金supported by the National Key Research and Development Program of China(No.2020YFB1713500)the Student Research Training Plan of Henan University of Science and Technology(No.2020026)the National Undergraduate Innovation and Entrepreneurship Training Program(Nos.202010464031,202110464005)。
文摘Lithium–sulfur(Li-S)batteries are regarded as one of the most promising energy storage devices because of their low cost,high energy density,and environmental friendliness.However,Li-S batteries suffer from sluggish reaction kinetics and serious“shuttle effect”of lithium polysulfides(LiPSs),which causes rapid decay of battery capacity and prevent their practical application.To address these problems,introducing single-atom catalysts(SACs)is an effective method to improve the electrochemical performance of Li-S batteries,due to their high catalytic efficiency and definite active sites for LiPSs.In this paper,we summarized the latest developments in enhancing the electrochemical performance of cathode for Li-S batteries through introducing different SACs.Furthermore,we briefly introduced the catalytic mechanism of SACs and discussed the strategies of synthesizing SACs,including the spatial confinement strategy and the coordination design strategy.Finally,the challenges and prospects in this field are proposed.We believe that this review would help to design and fabricate high-performance Li-S batteries via introducing SACs and boost their practical application.
文摘Subject Code:B02With the support by the National Natural Science Foundation of China and the National Basic Research Program of China,the research team led by Prof.Xia Haiping(夏海平)of Xiamen University described the first example of CCCCC pentadentate chelate with all binding atoms being carbon atoms.This result represents a new record of planar carbon coordination number for a transition metal,which was
