Single Idiosyncratic Ionic Generator Working in Iso-Osmotic Solutions Via Ligand Confined Assembled in Gaps Between Nanosheets

Abstract

Numerous reported bioinspired osmotic energy conversion systems employing cation-/anion-selective membranes and solutions with different salinity are actually far from the biological counterpart. The iso-osmotic power generator with the specific ionic permselective channels (e.g., K⁺ or Na⁺ channels) which just allow specific ions to get across and iso-osmotic solutions still remain challenges. Inspired by nature, we report a bioinspired K⁺-channel by employing a K⁺ selective ligand, 1,1,1-tris{[(2′-benzylaminoformyl)phenoxy]methyl}ethane (BMP) and graphene oxide membrane. Specifically, the K⁺ and Na⁺ selectivity of the prepared system could reach up to ≈17.8, and the molecular dynamics simulation revealed that the excellent permselectivity of K⁺ mainly stemmed from the formed suitable channel size. Thus, we assembled the K⁺-selective iso-osmotic power generator (KSIPG) with the power density up to ≈15.1 mW/m² between equal concentration solutions, which is higher than traditional charge-selective osmotic power generator (CSOPG). The proposed strategy has well shown the realizable approach to construct single-ion selective channels-based highly efficient iso-osmotic energy conversion systems and would surely inspire new applications in other fields, including self-powered systems and medical materials, etc.