Cation-Gated Ion Transport at Nanometer Scale for Tunable Power Generation br

Gated ion channels in biological cell membranes allow efficient tuning of cross-membrane ion transport with enhanced permeation and selectivity, converting ionic signals intovarious forms of electrical signals and energies on demands, which functionalities though are still difficult to achieve in artificial membranes. Here, we report cation-gated ion transport through synthesized porous aromaticfilms containing nanometer-scale ionic channels togetherwith-NH2groups at interiors. Ion selectivity and permeability is greatly tuned by gatingcations, up to 2 orders of magnitude, and as a consequence, the membrane efficiently producess witch able electricity output from salinity gradients. The results are attributed to positively charged cations binding at-NH2groups, which screens the intrinsic negative surface charge atchannels'interiors and inverts charge polarity there. Our work adds understanding to ion gating effects at nanoscale and offers strategies of developing smart membranes and their heterostructures for separation, energy conversion, cell membrane mimics, and related technologies