▎ 摘　　要

NOVELTY - Photothermal conversion material comprises hydrophilic layer located on hydrophilic surface of hydrophobic layer, where the hydrophilic layer is a agricultural and forestry residue layer, and the hydrophobic layer is a carbonized layer, graphene layer or carbon nanotube layer. USE - The photothermal conversion material is useful for desalinating sea water, performing steam distillation and treating sewage (claimed). ADVANTAGE - The photothermal conversion material is cost-effective and simple to prepare. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for producing photothermal conversion material, which involves crushing agricultural and forestry residues, adding adhesive and heating mixture, molding mixture, carbonizing upper surface of the mixture, or adding graphene or carbon nanotubes to form surface of the hydrophobic layer.