Modulating Solar Energy Harvesting on TiO₂ Nanochannel Membranes by Plasmonic Nanoparticle Assembly for Desalination of Contaminated Seawater

Abstract

Steam generation via harvesting solar energy is one of the promising approaches for seawater desalination. Nowadays, organic contamination in seawater represents a great challenge that needs to be solved. Specially, low-molecular-weight organic molecules may easily pass through distillation membranes with water steam and enter freshwater sources. In this study, we develop a solar distillation membrane (DM) for contaminated seawater desalination rather than grading treatment of contaminated seawater by integrating a large-scale TiO2 nanochannel membrane with plasmonic silver nanoparticles (Ag NPs) via inhomogeneous assembling. Such incorporation enables a self-upstanding DM acting as an efficient broad-band plasmonic absorber (200–2500 nm) and possessing high solar steam efficiencies (82% at 6 kW m–2), thus driving the photothermal desalination and photocatalytic decontamination in a synchronous fashion. The resulting membranes exhibit a rapid evaporation rate (7.14 kg m–2 h–1), helping in achieving fresh water from seawater contaminated with a high concentration of organics with remarkable durability and reusability. We believe the DM proposed in this study could pave the way for a promising point-of-use device to obtain fresh water from contaminated saline water.