Carbon materials for solar steam-generation

Steam can be generated by solar illumination of nanoparticles suspended in water, which is called "solar steamgeneration" and gets attention for the novel process for the production of drinkable water (water desalination). Recently, various carbon materials have been reported to be applicable for this process as solar energy absorbers (solar light receivers) with high conversion efficiency of light energy to thermal energy, mainly because of broad band solar absorption, capability for getting low bulk density (high porosity) to be self-floating on the water surface, etc., in addition to low costs for preparation. Here, we reviewed SSG performances by focusing on carbon materials, by classifying in the porous carbons, including carbon foams and activated carbons, graphite-based carbons, including reduced graphite oxides and graphene oxide, fibrous carbons, including carbon fibers, carbon nanofibers, carbon nanotubes and their clothes and webs, and biomass-derived carbons. The applicability of biomass-derived carbons prepared through simple carbonization processes to SSG process can reinforce the conformability to the coming "carbon neutral society". Recent results on co-generation of electric power with water desalination are also reviewed.