Polymeric Nano‐Blue‐Energy Generator Based on Anion‐Selective Ionomers with 3D Pores and pH‐Driving Gating

Abstract Blue energy as a renewable, substantial energy resource has attracted scientists who are interested in discovering abundant membrane materials to achieve high power density. For decades, ionomers have been used as ion‐exchange membrane to harvest this energy. Though extensive studies have been conducted, the underlying mechanism of ionic transmembrane behavior is still under debate. Here, the ionic transmembrane properties through membranes with 3D pores prepared by ionomers (polyphenylsulphone with pyridine pendants (PPSU‐Py)) are systematically studied. A series of PPSU‐Py with tunable porosities and surface charge densities is obtained simply by adjusting the percentages of the pendant. Nanoscale morphologies of the ionomers are simulated with the dissipative particle dynamic method, which is in agreement with the experimental data. Then, nanofluidic behaviors of as‐prepared porous membranes are studied, which exhibit anion selectivity, pH gating, and modulated transmembrane conductance. Furthermore, a series of salinity gradient power harvesters based on the ionomers are constructed, of which the output power density is improved by tuning the charge density with the maximum output power density that reaches up to 1.44 W m ‐2 . The impact of the ionomer on nanofluidic behavior is systematically discussed, and it is believed this work will shed light on nanofluidic materials and blue energy generator design.