▎ 摘　　要

NOVELTY - Photothermal conversion material comprises columnar structures spaced apart from one surface of the substrate, where material forming the substrate and columnar structures comprises graphene foam. USE - Photothermal conversion material used for seawater desalination, sewage treatment, preparation of a solar water heater or preparation of an ecological house system (claimed). ADVANTAGE - The photothermal conversion material has a three-dimensional structure, a large specific surface area, a good light absorption performance, a low thermal conductivity, a good solar thermal conversion performance, and a high photothermal conversion efficiency, which can absorb solar energy, and water is vaporized and the diffusion space of the water vapor is large.