Hydrogen-Bonded\nOrganic Framework Nanochannels for\nSalinity Gradient Energy Conversion

Abstract

The\nsalinity gradient at the seawater and river water interfaces\nis an abundant renewable energy source, which can be converted into\nelectrical power through the selective nanofluidic nanochannel membranes.\nHowever, the practical applications of reported nanomaterials are\nlimited by the poor ion selectivity and low ion flux. Herein, we demonstrate\nhydrogen-bonded organic framework (HOF) nanochannels for osmotic power\ngeneration. The porous structure formed by hydrogen bonds and π-π\ninteractions and the internal unprotonated carboxyl groups endow the\nHOF nanochannels with great cation selectivity and high ion flux.\nBy mixing seawater and river water, 44.4 wt % HOF nanochannel membranes\nexhibit a maximum output power density of 6.04 W/m², which\noutperforms the commercial benchmark of 5 W/m². This study\nlays the foundation for the applications of HOF to the harvest of\nsalinity gradient energy.