TRPM4-Inspired Polymeric Nanochannels with Preferential Cation Transport for High-Efficiency Salinity-Gradient Energy Conversion
Dehua Huang, Kehan Zou, Yuge Wu, Ke Li, Zhehua Zhang, Tianchi Liu, Weipeng Chen, Zidi Yan, Shengyang Zhou, Xiang‐Yu Kong, Lei Jiang, Liping Wen
Abstract
Biological ion channels exhibit switchable cation transport with ultrahigh selectivity for efficient energy conversion, such as Ca 2+ -activated TRPM4 channels tuned by cation−π interactions, but achieving an analogous highly selective function is challenging in artificial nanochannels. Here, we design a TRPM4-inspired cation-selective nanochannel (CN) assembled by two poly(ether sulfone)s, respectively, with sulfonate acid and indole moieties, which act as cation-selective activators to manage Na + /Cl – selectivity via ionic and cation−π interactions. The cation selectivity of CNs can be activated by Na +, and thereby the Na + transference number significantly improves from 0.720 to 0.982 (Na + /Cl – selectivity ratio from 2.6 to 54.6) under a 50-fold salinity gradient, surpassing the K + transference number (0.886) and Li + transference number (0.900). The TRPM4-inspired nanochannel membrane enabled a maximum output power density of 5.7 W m –2 for salinity-gradient power harvesting. Moreover, a record energy conversion efficiency of up to 46.5% is provided, superior to most nanochannel membranes (below 30%). This work proposes a novel strategy to biomimetic nanochannels for highly selective cation transport and high-efficiency salinity-gradient energy conversion.