Fig. 7: COF membranes with cations/anions selectivity for osmotic energy conversion.
From: Covalent organic framework membranes for selective ion separation
a Negative charged COF membrane with modulated charge density in the pore channels to enhance the permselectivity and ion conductance, leading to a larger osmotic voltage and current. Reproduced with permission from ref. 126 (copyright Wiley-VCH, 2022) b The sulfonic acid-functionalized 3D SCOF membrane deployed in osmotic energy conversion. Reproduced with permission from ref. 128 (copyright Springer Nature, 2023). c A pair of 100-nm-thick oriented COF membranes COF − SO3H − x and COF − QA−x for osmotic energy conversion. Reproduced with permission from ref. 129 (copyright American Chemical Society, 2022). d The COF-TAPB-BDTA membrane with aligned benzothiadiazole dipole moieties for salinity gradients energy extraction. Reproduced with permission from ref. 131 (copyright Wiley-VCH, 2024). e The β-ketoenamine linkage COF membrane with record permselectivity in high salinity environments employed in low-grade waste heat conversion. Reproduced with permission from ref. 132 (copyright Springer Nature, 2024).
