Electro-switchable nanofluidic Ti3C2TX membrane enables precise ion traffic control via anti-swelling hydrogel pillars

Bioinspired nanofluidic channels have garnered significant attention for their potential in ion sieving, energy conversion, and intelligent gating. However, conventional nano bionic channels often suffer from swelling in solutions, which compromises their ion transport regulation performance. To address these limitations, we designed a Mn 2+ -alginate intercalated Ti 3 C 2 T X membrane featuring interlayer channels narrower than 6.4 Å and excellent electrical conductivity. This structure exhibits exceptional anti-swelling stability (<2 % interlayer spacing variation), enabling precise ion transport control under voltage-gating effect. Under a positive voltage bias, the permeation rate of K + ions increased by a factor of 12 compared to the unbiased condition—representing a 2.05–3.5-fold improvement over previous reports. In contrast, under a −0.8 V bias, the permeation rate of Mg 2+ ions were strongly suppressed to only 6 % of the original rate. This outstanding gating performance stems from the tunability of the channel surface charge polarity and magnitude via applied voltage, which indirectly modifies the effective transport space for ions and constructs voltage-responsive ionic gates. Our nanoscale design advancing the development of intelligent nanofluidic systems for energy-efficient seawater desalination.