Efficiently cogenerating drinkable water and electricity from seawater via flexible MOF nanorod arrays

Abstract

Although solar vapor desalination via interface water evaporation (SDWIE) from seawater and evaporation-induced electricity generation from pure water or low concentration salt water, respectively, have been realized separately in different systems, cogenerating drinkable water and electricity from seawater via one device simultaneously is more desirable but still challenging. In this work, a flexible Cu-CAT-1 MOF nanorod array membrane with controllable 2D/3D structures is rationally designed via a facile solid conversion process at room temperature. The Cu-CAT-1 nanorod arrays anchor on filter paper via a thin gelatin layer. Due to unique hierarchical architectures, superior solar absorption, good photothermal conversion, high zeta potentials and outstanding hydrophilicity, the resulting membrane constructed 3D SDIWE device simultaneously displays extraordinary solar desalination performance (2.07 kg m⁻² h⁻¹ based on the projected area) and nice all-weather electricity output (18.2 mW m⁻²) using simulated seawater. It can power up small electronic devices such as calculators, timers and light-emitting diodes (LEDs). This provides a novel avenue for the design of drinkable water and electricity cogeneration devices.