本文要点：
以其有序结构而闻名的结晶多孔材料在具有有限离子密度的碱性燃料电池中具有高效的氢氧化物导电性。然而，多孔材料的刚性交联阻碍了它们加工成膜，而复合膜由于相的中断而降低了材料的导电性优势。
在这里，作者报告了一个独立的三维共价有机框架(3D COF)膜，通过其互连的3D离子纳米通道进行有效的OH-转运。大面积、均匀连接的COF膜，直径为8厘米，厚度为20微米，采用界面聚合策略，辅助以聚丙烯腈膜的牺牲模板来制备。
在微观水平上，咪唑盐构建单元的引入导致了3D COF的非萜烯化结构，为OH-传导创造了3D交互式连续亲水通道。3D COF膜表现出高电导率(在80°C、100%湿度下为169 mS/cm ),并在H2/O2单电池测试中实现了160 mW/cm2的峰值功率密度。
这种COF界面聚合策略为解决多孔材料膜形成的挑战带来了新的可能性，并有望推进其在离子传输领域的实际应用。
Figure 1. Synthesis and structure of 3D COFs. Synthetic condition and structures of TAM-BFBIm-iCOF, TAM-BFBZ-COF, and TAM-TPDACOF.
Figure 2. Structure and crystallinity. (a) The 1-fold interpenetrated dia topology and PXRD pattern of TAM-BFBIm-iCOF (b) The 7-fold interpenetrated dia topology and PXRD pattern of TAM-BFBZ-COF. (c) The 7-fold interpenetrated dia topology and PXRD pattern of TAM-TPDA-COF.
Figure 3. Preparation and structure of the TAM-BFBIm-iCOF membrane. (a) Schematic diagram for TAM-BFBIm-iCOF membrane preparation and the formation process. (b) XRD patterns and photographs of the TAM-BFBIm-iCOF membrane (black) and TAM-BFBIm-iCOF powder (pink). (c) SEM images and TEM image (upper right) of the TAM-BFBIm-iCOF membrane. (d) SEM cross-sectional image and EDS maps of the TAM-BFBIm-iCOF membrane and the corresponding distribution of carbon, bromine, nitrogen, and oxygen.
Figure 4. Structure and hydroxide conductivity of the membrane. (a) Schematic diagram of hydroxide transfer in the TAM-BFBIm-iCOF membrane. (b) Nyquist plots were obtained at different temperatures for the TAM-BFBIm-iCOF membrane. (c) Arrhenius activation energy of the TAM-BFBIm-iCOF membrane for hydroxide ion conductivity. (d) Polarization and power density curves of the TAM-BFBIm-iCOF membrane tested in the H2/O2 single-cell AEMFC at 60 °C and 100% RH.
https://doi.org/10.1021/jacs.4c16029
