▎ 摘　　要

NOVELTY - Method for preparing a sheet-shaped porous graphene quantum dot/phosphorylated copper composite material, involves (i) self-assembling using a mixed aqueous solution of graphene quantum dots, and copper acetate as a precursor solution, (ii) freeze-drying to obtain a graphene quantum dot/metal ion precursor having a sheet-like structure, and (iii) using sodium hypophosphite as a phosphorus source, and converting the precursor into the target material through a low-temperature phosphating method. USE - The method is useful for preparing the composite material which is useful in a photothermal seawater desalination (all claimed). ADVANTAGE - The method utilizes wide source of components, involves easy operation and has high cost performance.