Nanofluidic energy conversion and molecule separation through highly stable clay-based membranes
Energy collection and molecule separation are two emerging applications based on membrane technologies. It remains a challenge to improve the separation performance of molecular channels. Meanwhile, the applications of membranes are typically impeded by their poor stability under practical hydrous conditions. Herein, we present the fabrication of a uniformly lamellar membrane using montmorillonite nanosheets as building blocks. We managed to achieve nanofluidic ion transport and molecule separation simultaneously. The membrane nanochannels possess nanofluidic ion transport properties with an output power density up to 0.18 W m-1 at a membrane thickness of 11.2 μm under a 1000-fold transmembrane concentration difference. The membrane also shows water permeance of 429 L m-2 h-1 atm-1 at a thickness of 2.5 μm and high separation efficiency for both cationic and anionic dyes. Moreover, the montmorillonite-based membranes can maintain a high stability in aqueous conditions under soaking, shaking, and even ultrasonication.