Catalyst-free nitro-coupling synthesis of azo-linked conjugated microporous polymers with superior aqueous energy storage capability  

无催化剂硝基偶联合成偶氮基共轭微孔聚合物及其水系储能研究

作　　者：Dianlei Fang Xinlei Wang Shijie Zhang Lingyan Sheng Jian Tang Jie Zhou Weihua Tang 房佃磊;王鑫磊;张士杰;盛玲艳;唐键;周杰;唐卫华(School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing,210094,China)

机构地区：[1]School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing,210094,China

出　　处：《Science China Materials》2022年第4期958-966,共9页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(51861145401,21905136);the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。

摘　　要：Developing methods to construct conjugated microporous polymers(CMPs)with desirable structures is a crucial undertaking.However,obtaining azo-CMPs with extended azaacene cores is immensely challenging.Herein,we disclose the facile synthesis of diquinoxalino[2,3-a:2',3'-c]-phenazine-core CMP(3Qn-CMP;core diameter,∼1.6 nm)via the one-step hydrothermal homocoupling of nitro monomers in a mixture solution of N,N-dimethylformamide(or N,N-dimethylacetamide)and water(1:3,v/v).A 3Qn-CMP/rGO hybrid is readily prepared from CMP spheres(diameter,0.5-1.5µm)anchored on reduced graphene oxide(rGO)nanosheets(∼3 layers)by synergizing the one-pot synthesis of(rGO)for intercalation and self-assembly.The highly porous hybrid features dual redox active sites with azo and imine linkages and efficient charge conduction.3Qn-CMP and 3Qn-CMP/rGO exhibit outstanding energy storage capacity,current density tolerance(1-50 A g^(−1)),and long-term cycling stability in aqueous acidic electrolytes.3Qn-CMP and 3Qn-CMP/rGO also produce high specific capacitances of 615.4 and 847.8 F g^(−1),respectively,at 1 A g^(−1).Approximately 99.1%of this capacitance can be retained over 50,000 continuous charge/discharge cycles at 50 A g^(−1).To the best of our knowledge,our hybrid outperforms most organic molecules or CMP-/rGO-based composites reported in the literature in terms of capacitance and cycling durability.This work provides a general strategy to access a new library of CMPs and hybrids with multilevel elaborate architectures tailored for target applications,such as electrochemical energy storage and catalysis.发展可构建材料结构的方法对于共轭微孔聚合物(CMP)具有重要意义.目前,以偶氮键桥联氮杂并苯共轭微孔聚合物的合成仍具有极大的挑战.在此,我们以硝基化二喹喔啉并[2,3-a:2′,3′-c]吩嗪为单体,在N,N-二甲基甲酰胺与水混合溶剂中(1:3,v/v)一步水热还原合成偶氮基共价有机框架(孔径为~1.6 nm).通过原位一步还原氧化石墨烯(rGO)进行插层与自组装,获得的3Qn-CMP/rGO复合材料中CMP微球(粒径0.5-1.5µm)锚定于rGO纳米片层上(~3层).该多孔复合物具有偶氮和亚胺双重氧化还原位点及高电荷传导能力.3Qn-CMP和3Qn-CMP/rGO均在酸性水系电解质中表现出优异的电荷储存能力,倍率性(1-50 A g^(−1))和长期循环稳定性.在1 A g^(−1)的电流密度下,它们分别实现615.4和847.8 F g^(−1)的比电容,在50 A g^(−1)下充放电50,000次后的保留率高达99.1%.据我们所知,该比容量和循环稳定性优于文献中多数有机分子或CMP复合材料.该工作提供了多重结构偶氮共轭多孔聚合物材料及复合物的普适性合成策略,有望应用于电化学储能和催化等领域.

关 键 词：conjugated microporous polymers nitro-coupling AZO hydrothermal reaction energy storage 

分 类 号：O631.5[理学—高分子化学]