Ultra-thin two-dimensional(2D)organic semiconductors are promising candidates for photocatalysts because of the short charge diffusion pathway and favorable exposure of active sites plus the versatile architecture.Non...Ultra-thin two-dimensional(2D)organic semiconductors are promising candidates for photocatalysts because of the short charge diffusion pathway and favorable exposure of active sites plus the versatile architecture.Nonetheless,the inherent dielectric confinement of 2D materials will induce a strong exciton effect hampering the charge separation.Herein,we demonstrated an effective way to reduce the dielectric confinement effect of 2D ionic covalent organic nanosheets(iCONs)by tailoring the functional group via molecular engineering.Three ultra-thin CONs with different functional groups and the same ionic moieties were synthesized through Schiff base condensation between ionic amino monomer triaminoguanidinium chloride(TG)and aldehyde linkers.The integration of the hydroxyl group was found to significantly increase the dielectric constant by enhancing the polarizability of ionic moieties,and thus reduced the dielectric confinement and the corresponding exciton binding energy(E_(b)).The champion hydroxyl-functional iCON exhibited promoted exciton dissociation and in turn a high photocatalytic hydrogen production rate under visible-light irradiation.This work provided insights into the rationalization of the dielectric confinement effect of low-dimensional photocatalysts.展开更多
Ionic covalent organic frameworks featuring both crystallinity and charged sites have arose tremendous attention from scientific community. The adjustable textural structures, well-defined channels and abundant charge...Ionic covalent organic frameworks featuring both crystallinity and charged sites have arose tremendous attention from scientific community. The adjustable textural structures, well-defined channels and abundant charged sites of ionic COFs facilitate great potential in diverse aspects, such as separation, ion conduction, sensing, catalysis and energy storage. In this review, we first introduced the design and construction of ionic covalent organic frameworks(COFs), and classified them according to the types of charged sites. We focused on the various applications of ionic COFs in diverse fields. The structure-function relationship was also explored in detail. Finally, the opportunities and challenges of ionic COFs were summarized to provide guidance for better design and application of ionic COFs.展开更多
基金the National Natural Science Foundation of China(22072065,22178162,22222806)the Distinguished Youth Foundation of Jiangsu Province(BK20220053)the Six Talent Peaks Project in Jiangsu Province(JNHB-035)。
文摘Ultra-thin two-dimensional(2D)organic semiconductors are promising candidates for photocatalysts because of the short charge diffusion pathway and favorable exposure of active sites plus the versatile architecture.Nonetheless,the inherent dielectric confinement of 2D materials will induce a strong exciton effect hampering the charge separation.Herein,we demonstrated an effective way to reduce the dielectric confinement effect of 2D ionic covalent organic nanosheets(iCONs)by tailoring the functional group via molecular engineering.Three ultra-thin CONs with different functional groups and the same ionic moieties were synthesized through Schiff base condensation between ionic amino monomer triaminoguanidinium chloride(TG)and aldehyde linkers.The integration of the hydroxyl group was found to significantly increase the dielectric constant by enhancing the polarizability of ionic moieties,and thus reduced the dielectric confinement and the corresponding exciton binding energy(E_(b)).The champion hydroxyl-functional iCON exhibited promoted exciton dissociation and in turn a high photocatalytic hydrogen production rate under visible-light irradiation.This work provided insights into the rationalization of the dielectric confinement effect of low-dimensional photocatalysts.
基金supported by the National Natural Science Foundation of China(Nos.22178280,21773223)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2020JM-005,2020JQ-017)+2 种基金the Fundamental Research Funds for the Central Universities,China(No.xzy012019027)the Fundamental Research Funds for“Young Talent Support Plan”of Xi'an Jiaotong University,China(No.HG6J001)the“1000-Plan Program”of Shaanxi Province,China.
文摘Ionic covalent organic frameworks featuring both crystallinity and charged sites have arose tremendous attention from scientific community. The adjustable textural structures, well-defined channels and abundant charged sites of ionic COFs facilitate great potential in diverse aspects, such as separation, ion conduction, sensing, catalysis and energy storage. In this review, we first introduced the design and construction of ionic covalent organic frameworks(COFs), and classified them according to the types of charged sites. We focused on the various applications of ionic COFs in diverse fields. The structure-function relationship was also explored in detail. Finally, the opportunities and challenges of ionic COFs were summarized to provide guidance for better design and application of ionic COFs.
