Reduced Graphene Oxide–Polyurethane Nanocomposite Foam as a Reusable Photoreceiver for Efficient Solar Steam Generation

Solar steam generation driven by local hot spots is an efficient route to use solar energy. We introduce a novel photoreceiver composed of reduced graphene oxide (rGO) and polyurethane (PU) matrix for highly efficient solar steam generation. The rGO nanosheets covalently cross-linked to PU matrix provide excellent stability and broad optical absorption, together with the property of thermal insulation served by PU resulting in rapid increase of local thermal under illumination. Moreover, the hydrophilic segments and the interconnected pores of rGO/PU can be worked as water channels for replenishment of surface water evaporated. With excellent mechanical and chemical stability, the functional rGO/PU foam exhibited a solar photothermal efficiency of ∼81% at a light density of 10 kW/m2. The novel macro design demonstrated here is low cost, simple to prepare, and highly stable, being suitable for a series of practical applications in massive seawater desalination, solar steam generation, and sterilization of waste.