Zhou Bin, Le Jiabo, Cheng Zhangyuan, Zhao Xuan, Shen Ming, Xie Maoling, Hu Bingwen, Yang Xiaodong, Chen Liwei, Chen Hongwei
College of Materials Science and Engineering , Huaqiao University , Xiamen 361021 , China.
State Key Laboratory of Physical Chemistry of Solid Surfaces, IChEM, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8198-8205. doi: 10.1021/acsami.9b19953. Epub 2020 Feb 6.
We report the rational design and implementation of a new class of gel guest-assisted, ionic covalent organic framework (COF) membranes that exhibit superior H conduction. The as-synthesized COFs are postmodified via a lithiation (or sodiation) treatment. The hydrophilic Li or Na ions in the COFs form a dense and extensive hydrogen-bonding network of HO molecules with mobile H at the periphery, thereby transforming COFs into H conductors. Then, the ionic COFs are assembled into a flexible H conductor membrane via a gelation process, where the organic gel provides both mechanical strength and additional H carriers for fast H conduction. The final COF-based membrane exhibits an excellent H conductivity of 1.3 × 10 S cm at 313 K and 98% relative humidity, which are the highest values of the COF-based H conductors reported until now and are even comparable with those of the typical commercial Nafion membrane. We anticipate that the two-in-one strategy would open up a porous COF-driven new molecular framework and membrane architectural design/opportunity for development of next-generation ionic conductors.
我们报道了一类新型的凝胶客体辅助离子共价有机框架（COF）膜的合理设计与实现，该膜表现出优异的氢传导性能。合成后的COF通过锂化（或钠化）处理进行后修饰。COF中的亲水性锂或钠离子与外围具有移动氢的水分子形成密集且广泛的氢键网络，从而将COF转化为氢导体。然后，离子型COF通过凝胶化过程组装成柔性氢导体膜，其中有机凝胶既提供机械强度又提供额外的氢载体以实现快速氢传导。最终的基于COF的膜在313 K和98%相对湿度下表现出1.3×10 S cm的优异氢导率，这是迄今为止报道的基于COF的氢导体的最高值，甚至可与典型的商业Nafion膜相媲美。我们预计这种二合一策略将为下一代离子导体的开发开辟一个由多孔COF驱动的新分子框架和膜结构设计/机会。
