Silk nanofibril as nanobinder for preparing COF nanosheet-based proton exchange membrane

作     者：Ping Li Ningxin Zhang Xuan Li Shaokun Tang Ping Li;Ningxin Zhang;Xuan Li;Shaokun Tang

作者机构：School of Chemical Engineering&TechnologyTianjin UniversityTianjinChina Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin UniversityTianjinChina 

出 版 物：《Green Energy & Environment》 (绿色能源与环境（英文版）)

年 卷 期：2023年第8卷第3期

页      面：915-926页

核心收录：

学科分类：0821[工学-纺织科学与工程] 0808[工学-电气工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

主　　题：Covalent organic framework nanosheet Silk nanofibril Membrane Proton conductivity Fuel cell 

摘      要：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.