▎ 摘　　要

NOVELTY - Modified nanocatalyst comprises cadmium sulfide (CdS) as the core and nitrogen-graphene quantum dots-cadmium sulfide (N-GQDs) grown on the surface, where the two are connected by covalent bonds, and the N-GQDs are graphene quantum dots doped with nitrogen. USE - The nanocatalyst is useful in degrading dye waste water (claimed). ADVANTAGE - The nanocatalyst can expand the light absorption range and facilitate hole-electron separation; improves the catalytic efficiency; has good degradation ability to methylene blue and methyl orange under ultraviolet light conditions. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing nanocatalyst comprising (i) dissolving citric acid and ammonium carbonate in water and ultrasonically dispersing, transferring into a reactor for hydrothermal reaction, cooling, performing rotary evaporation and drying in sequence to obtain N-GQDs; and (ii) dissolving N-GQDs in water, adding cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide to mix and ultrasonically dispersing, transferring to the reactor for hydrothermal reaction, sequentially cooling down, washing and drying.