Two-dimensional(2 D) materials have attracted increasing attentions recently due to their unique physical and chemical properties. We herein report the synthesis of four chemically stable 2 D covalent organic nanosh...Two-dimensional(2 D) materials have attracted increasing attentions recently due to their unique physical and chemical properties. We herein report the synthesis of four chemically stable 2 D covalent organic nanosheets(CONs) with large lateral sizes(up to 200 mm) and high aspect ratios(〉20 000) at the air-water interface through the Langmuir-Blodgett method. These CONs exhibit good crystallinity proved by high resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED). In addition, the hydrophobicity of these CONs can be systematically adjusted by the introduction of various functional groups, making them suitable as functional coating and membrane materials.展开更多
Two-dimensional covalent organic framework nanosheets(CONs)with ultrathin thickness and porous crystalline nature show substantial potential as novel membrane materials.However,bringing CONs materials into flexible me...Two-dimensional covalent organic framework nanosheets(CONs)with ultrathin thickness and porous crystalline nature show substantial potential as novel membrane materials.However,bringing CONs materials into flexible membrane form is a monumental challenge due to the limitation of weak interactions among CONs.Herein,one-dimensional silk nanofibrils(SNFs)from silkworm cocoon are designed as the nanobinder to link sulfonated CON(SCON)into robust SCON-based membrane through vacuum-filtration method.Ultrathin and large lateral-sized SCONs are synthesized via bottom-up interface-confined synthesis approach.Benefiting from high length-diameter ratio of SNF and rich functional groups in both SNF and SCON,two-dimensional(2D)SCONs are effectively connected together by physical entanglement and strong H-bond interactions.The resultant SCON/SNF membrane displays dense structure,high mechanical integrity and good stability.Importantly,the rigid porous nanochannels of SCON,high-concentration-SO3H groups insides the pores and H-bonds at SCON-SNF interfaces impart SCON/SNF membrane high-rate proton transfer pathways.Consequently,a superior proton conductivity of 365 mS cm^(-1)is achieved at 80C and 100%RH by SCON/SNF membrane.This work offers a promising approach for connecting 2D CON materials into flexible membrane as high-performance solid electrolyte for hydrogen fuel cell and may be applied in membrane-related other fields.展开更多
Two-dimensional(2D)covalent organic framework nanosheets(CONs)are attracting increasing research attention because of their unique properties derived from their ultrathin thickness,high surface-tovolume atomic ratio,a...Two-dimensional(2D)covalent organic framework nanosheets(CONs)are attracting increasing research attention because of their unique properties derived from their ultrathin thickness,high surface-tovolume atomic ratio,and extremely large surface area.2D CONs can provide high transport pathways for charge carriers(e.g.,electrons,holes and ions)through either the conjugated skeletons or the open channels.Therefore,they have shown great potential in energy related applications.In this review,we firstly introduce the recent developments and characteristics of 2D CONs by focusing on the two typical synthetic methods,i.e.,top-down and bottom-up methods.Then,the energy-related applications in energy storage and conversion of 2D CONs are summarized.Finally,we give our personal views on the challenges and perspectives for the future research of 2D CONs and their composites.展开更多
The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploi...The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploited to fully realize oxidase-like nanozyme in the emerging covalent organic frameworks(COFs)due to their polymeric nature and weak photoelectric activity.We herein report the first example of the preparation and oxidase-mimicking activity of novel ultrathin two-dimensional(2D)COF(termed as TTPA-COF)nanosheets.The ultrathin TTPA-COF nanosheets with hexagonal layered structure are constructed from two flexible photoactive(diarylamino)benzene-based linkers,and exhibit remarkable catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of O_(2) due to their large specific surface areas and abundant active sites.Moreover,it is worth noting that the nanozyme activity could be regulated by external light irradiation.Based on the oxidasemimicking activity of TTPA-COF nanosheets,a green colorimetric sensor is proposed for the sensitive and selective determination of glutathione(GSH)in a wide linear range of 0.5–40μM with a detection limit of 0.5μM.This work reported here would open new avenues for the exploration of low-cost and high-efficiency nanozymes,as well as extend the application of 2D COF nanosheets in the fields of catalysis and sensing.展开更多
基金supported by National University of Singapore No. CENGas R-261-508-001-646)Ministry of Education – Singapore ( 13No. MOE Ac RF Tier 1 R-279-000-472-112)
文摘Two-dimensional(2 D) materials have attracted increasing attentions recently due to their unique physical and chemical properties. We herein report the synthesis of four chemically stable 2 D covalent organic nanosheets(CONs) with large lateral sizes(up to 200 mm) and high aspect ratios(〉20 000) at the air-water interface through the Langmuir-Blodgett method. These CONs exhibit good crystallinity proved by high resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED). In addition, the hydrophobicity of these CONs can be systematically adjusted by the introduction of various functional groups, making them suitable as functional coating and membrane materials.
文摘Two-dimensional covalent organic framework nanosheets(CONs)with ultrathin thickness and porous crystalline nature show substantial potential as novel membrane materials.However,bringing CONs materials into flexible membrane form is a monumental challenge due to the limitation of weak interactions among CONs.Herein,one-dimensional silk nanofibrils(SNFs)from silkworm cocoon are designed as the nanobinder to link sulfonated CON(SCON)into robust SCON-based membrane through vacuum-filtration method.Ultrathin and large lateral-sized SCONs are synthesized via bottom-up interface-confined synthesis approach.Benefiting from high length-diameter ratio of SNF and rich functional groups in both SNF and SCON,two-dimensional(2D)SCONs are effectively connected together by physical entanglement and strong H-bond interactions.The resultant SCON/SNF membrane displays dense structure,high mechanical integrity and good stability.Importantly,the rigid porous nanochannels of SCON,high-concentration-SO3H groups insides the pores and H-bonds at SCON-SNF interfaces impart SCON/SNF membrane high-rate proton transfer pathways.Consequently,a superior proton conductivity of 365 mS cm^(-1)is achieved at 80C and 100%RH by SCON/SNF membrane.This work offers a promising approach for connecting 2D CON materials into flexible membrane as high-performance solid electrolyte for hydrogen fuel cell and may be applied in membrane-related other fields.
基金the Class D of Qianjiang Talent Program(No.ZD20011250001)the start-up grant(No.2019125016829)in Zhejiang University of Technology+1 种基金the financial support from the funding of"Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang"(No.2020R01002)the financial support from the National Natural Science Foundation of China(No.51907173)。
文摘Two-dimensional(2D)covalent organic framework nanosheets(CONs)are attracting increasing research attention because of their unique properties derived from their ultrathin thickness,high surface-tovolume atomic ratio,and extremely large surface area.2D CONs can provide high transport pathways for charge carriers(e.g.,electrons,holes and ions)through either the conjugated skeletons or the open channels.Therefore,they have shown great potential in energy related applications.In this review,we firstly introduce the recent developments and characteristics of 2D CONs by focusing on the two typical synthetic methods,i.e.,top-down and bottom-up methods.Then,the energy-related applications in energy storage and conversion of 2D CONs are summarized.Finally,we give our personal views on the challenges and perspectives for the future research of 2D CONs and their composites.
基金supported by the financial support from the National Natural Science Foundation of China(NSFC)(Nos.21976166,22006122,and 21405144)the research funding of“Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang”(No.2020R01002)+4 种基金the Class D of Qianjiang Talent Program(No.ZD20011250001)the Science Challenge Project(No.TZ2016004)he Project of State Key Laboratory of Environment-friendly Energy Materials(No.18zd320303)the Scientific Research Starting Foundation for Returned Overseas Chinese Scholars of Sichuan Province(No.19zd3200)support from the Opening Project of Jiangsu Province Engineering Research Center of Agricultural Breeding Pollution Control and Resource(No.2021ABPCR004).
文摘The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploited to fully realize oxidase-like nanozyme in the emerging covalent organic frameworks(COFs)due to their polymeric nature and weak photoelectric activity.We herein report the first example of the preparation and oxidase-mimicking activity of novel ultrathin two-dimensional(2D)COF(termed as TTPA-COF)nanosheets.The ultrathin TTPA-COF nanosheets with hexagonal layered structure are constructed from two flexible photoactive(diarylamino)benzene-based linkers,and exhibit remarkable catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of O_(2) due to their large specific surface areas and abundant active sites.Moreover,it is worth noting that the nanozyme activity could be regulated by external light irradiation.Based on the oxidasemimicking activity of TTPA-COF nanosheets,a green colorimetric sensor is proposed for the sensitive and selective determination of glutathione(GSH)in a wide linear range of 0.5–40μM with a detection limit of 0.5μM.This work reported here would open new avenues for the exploration of low-cost and high-efficiency nanozymes,as well as extend the application of 2D COF nanosheets in the fields of catalysis and sensing.