Mesoporous Three-Dimensional Graphene Networks for Highly Efficient Solar Desalination under 1 Sun Illumination

Abstract

Solar desalination via thermal evaporation of abundant seawater is one of the most promising technologies to address the serious global water scarcity problem since it does not require additional supporting energy other than infinite solar energy for generating clean water. However, low efficiency and a large amount of heat loss are considered critical limitations of solar desalination technology. The combination of mesoporous three-dimensional graphene networks (3DGNs) with a high solar absorption property and water transporting wood pieces with a thermal insulation property has shown greatly enhanced solar to vapor conversion efficiency. 3DGN deposited on a wood piece provides a world record value of solar to vapor conversion efficiency, about 91.8%, under one sun illumination and excellent desalination efficiency of five orders salinity decrement. The mass-producible 3DGN enriched with many mesopores efficiently releases the vapors from the enormous area of the surface by heat localization on the top surface of the wood piece. Because the efficient solar desalination device made by 3DGN on the wood piece is highly scalable and inexpensive, it could serve as one of the main sources for the worldwide supply of purified water achieved via earth-abundant materials without an extra supporting energy source.