Solar-driven simultaneous steam production and electricity generation from salinity

Abstract

Solar-driven interfacial water evaporation, which concentrates solar heating at the water surface, has attracted increasing interest in pursuing highly efficient solar desalination. The rapid evaporation of water at the light absorber surface would induce a high concentration comparable with that of brine underlying the interface, which however has been paid much less attention and has never been proposed to produce electricity. Here in this work, we proved that, the theoretical real-time salinity power generated between the surface water and bulk seawater could be 12.5 W m⁻² during steam production under one sun illumination. By employing a hybrid system based on a piece of carbon nanotube modified filter paper and a commercial Nafion membrane, we achieved a maximum solar thermal efficiency of up to 75% and derived extra electricity power of ∼1 W m⁻² under one sun illumination. These results provide a novel avenue for blue energy utilization, demonstrating the potential for solar desalination and electricity generation under natural sunlight simultaneously.