▎ 摘　　要

The widespread use and uncontrolled diffusion of nano-carbon materials are bringing threats to human health because the cytotoxicity of such materials increases over certain in-vivo concentrations. In the present study, the cytotoxicity of graphene quantum dots (GQDs) was reduced after photocatalysis with TiO2 and ultraviolet light. The FTIR and TEM analysis suggested that the hydrophilic functional groups of GQDs were removed, causing the aggregation of the nanoparticles and the reduction of water-diffused concentration. The treatment is valuable for the disposal of nano-carbon materials in the wastewater.