Authors: Tianhao Zhu, Yan Kong, Bohui Lyu, Li Cao, Benbing Shi, Xiaoyao Wang, Xiao Pang, Chunyang Fan, Chao Yang, Hong Wu, Zhongyi Jiang
Published: 2023-09-22
DOI: 10.1038/s41467-023-41555-5
Source: Full article
Abstract3D ionic covalent organic framework (COF) membranes, which are envisioned to be able to break the trade-off between ion conductivity and ion selectivity, are waiting for exploitation. Herein, we report the fabrication of a 3D sulfonic acid-functionalized COF membrane (3D SCOF) for efficient and selective ion transport, using dual acid-mediated interfacial polymerization strategy. The 3D SCOF membranes possess highly interconnected ion transport channels, ultramicroporous pore sizes (0.97 nm), and abundant sulfonate groups (with a high ion exchange capacity of 4.1 mmol g−1), leading to high proton conductivity of 843 mS cm−1 at 90 °C. When utilized in osmotic energy conversion, a high power density of 21.2 W m−2, and a remarkable selectivity of 0.976 and thus an exceptional energy conversion efficiency of 45.3% are simultaneously achieved. This work provides an alternative approach to 3D ionic COF membranes and promotes the applications of 3D COFs in ion transport and separation.